In this Ralph Alger Bagnold medal lecture I will present a tour of the world’s mighty and kilometers-thick ice sheets that existed in the last glacial. The journey will take us to palaeo ice sheets of North America, Greenland, Britain and Ireland, Scandinavia, northern Europe, Russia and Antarctica.  Having looked at glacial landforms in all these locations I will attempt to show what they tell us about processes of formation and the functioning of ice sheets.  There are some important lessons to help us forecast future ice sheets and sea level. For example, to what extent does the history of an ice sheet matter for its future dynamics and change? A theme will be on my four-decade journey, riding the wave of increasing spatial resolution which started with peering into the gloom of fuzzy satellite images. I will show that the renaissance in mapping, description and untangling of landform patterns have been pivotal in advancing knowledge. Further themes will include: the troublesome problem of scale; building large geomorphological and geochronological databases; reconciling field to continental-scale observations; numerical modelling of landform creation; and recent advances on integrating numerical ice sheet modelling approaches with empirical data sets.

I am likely to reflect (or rant) on some diversions such as on the third referee, the freedom of PhD research against grant deliverables, the need to study nature not books, that it takes a long time and many people to make progress on hard problems, and on the importance to geomorphology of a wide diversity of researchers in how they think.

How to cite: Clark, C. D.: Landforms in focus; riding the wave of increasing spatial resolution, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6235, https://doi.org/10.5194/egusphere-egu25-6235, 2025.

High mountain environments are disproportionately affected by climate change. Around the world, mountain glaciers are retreating, leaving unstable sediments behind. Thawing permafrost and changing rainfall conditions make many mountain slopes unstable and increase natural hazards. Plants colonize the newly available terrain, but also need to shift upslope to survive rising temperature, threatening biodiversity. What will happen in the future? Might unstable sediments and moving slopes limit plant colonization and shifts? Or can colonizing and shifting plants actually stabilize moving sediments and slopes? This depends on biogeomorphic feedbacks!

In this award lecture, I will take you on a journey through recent finding and advances in “mountain biogeomorphology”, the discipline investigating feedbacks between moving mountain slopes and dynamic mountain plants. Our journey will start in the front of retreating glaciers. Here, I will illustrate the strong biogeomorphic feedbacks between paraglacial geomorphic processes and vegetation succession, mediated by “ecosystem engineer” plants that not only stabilize moving moraine slopes but also promote periglacial landform development, soil formation and vegetation succession.

In a second part, I will evaluate the role of biogeomorphic feedbacks in a changing climate. Using a “biogeomorphic balance” concept, we will assess how biogeomorphic feedbacks can influence future slope movements, vegetation shifts, natural hazards and biodiversity in different scenarios. Finally, I will take you to the current research frontiers in mountain biogeomorphology. I will illuminate the yet not fully understood role of plant traits and sediment properties as key controls for biogeomorphic feedbacks. Subsequently, we will explore how increasing data availability and novel methods, including artificial intelligence (AI) techniques, can help to unravel biogeomorphic feedback mechanisms and dynamics. Thereby, mountain biogeomorphic research can advance understanding and mitigation of climate change impacts on high mountain environments.

How to cite: Eichel, J.: Feedbacks between moving mountain slopes and dynamic mountain plants, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16685, https://doi.org/10.5194/egusphere-egu25-16685, 2025.

This research investigates the alongshore variability of shoreline and dune line responses to storm events and long-term changes on Culatra Island, located in the Algarve region of Portugal utilizing a combination of LiDAR data, satellite imagery, and numerical models (ShorelineS and SnapWave). Using a dune model based on Larson et al. (2016), integrated within the ShorelineS framework, to analyze the dynamic interactions between dune erosion, overwash by waves, and dune growth driven by aeolian (wind) transport. These interactions are critical in understanding the long-term and storm-induced changes in shoreline positions.

The calibrated ShorelineS model, supported by SnapWave's wave data, reveals that longshore transport gradients are the predominant drivers of shoreline change, significantly influenced by southeast prevailing waves, shallow active heights at the ebb delta, and the presence of the western breakwater.

By simplifying these processes into a 1D sand balance equation, where dune interactions are treated as source and sink terms, the model effectively captures several key dynamics of coastal morphology. However, certain idealizations, such as the assumed dune vegetation lines and simplified coastal profiles, result in some processes, like overwash, not being fully represented.

To ensure the accuracy and reliability of the model outputs, extensive sensitivity analyses were conducted with parameters such as impact coefficient Cs, median grain size d50, wave output points distances, and sediment transport factor (qscal). Validation of the ShorelineS model against 2011 DEM data and satellite trends reveals varying degrees of accuracy. For shoreline positions, the model demonstrates a strong positive correlation with DEM data (R² = 0.78) and even better alignment with satellite trends (R² = 0.85). However, the model's predictions for dune positions exhibit higher variability and weaker correlations with DEM data (R² = 0.47), indicating significant discrepancies. Interestingly, the model shows a stronger positive correlation with satellite trends for dunes (slope = 0.96).

The research identifies several key factors contributing to alongshore variability in dune and shoreline responses during storm events, including initial berm width, storm duration, wave height, and cumulative sediment transport due to dune erosion. Notably, dune responses exhibit higher sensitivity to these coastal parameters compared to shoreline responses, with cumulative sediment transport being a significant driver of dune change (Corr: -0.86).

Overall, this study highlights the critical need for integrating comprehensive modeling approaches with empirical data to inform coastal management practices. It offers a robust framework for future research aimed at enhancing the sustainability and resilience of coastal environments.

How to cite: Dabu, R., Roelvink, D., van Dongeren, A., and Garzon, J.: Alongshore Varying Dune Retreat at a Barrier Island, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-770, https://doi.org/10.5194/egusphere-egu25-770, 2025.

As decision support methods (including as Artificial Intelligence supported decision making) progress, new ways and frameworks are emerging to enhance our understanding of sediment transport processes (via improved monitoring), but also better modeling those phenomena. This study offers a preliminary view of how deep learning models can link with real-time data from instrumented sediment particles, to predict the risk of bed surface destabilization in channels and rivers, which can lead to infrastructure scour. 
Specifically, three deep learning models are analyzed, herein: a) Long Short-Term Memory (LSTM), b) Gated Recurrent Units (GRU), and c) Transformers. These models were compared according to their accuracy, computational efficiency, and suitability for real-time applications.This study integrates data from specifically designed sediment stability monitoring sensors [1-3], with three deep learning models to predict the possibility that sediment is transported along the bed surface of the river [4], in real time. This is important for a series of applications, such as flood risk management, assessment of hazards to hydraulic infrastructure and water resource management, helping achieve resilient and sustainable development under a changing climate change. Future studies can explore further improving the efficiency of sensor enabled novel hydroinformatics approaches.

References
[1] Al-Obaidi, K., Xu, Y., & Valyrakis, M. (2020). The design and calibration of instrumented particles for assessing water infrastructure hazards. Journal of Sensor and Actuator Networks, 9(3), 36.
[2] AlObaidi, K., & Valyrakis, M. (2021). Linking the explicit probability of entrainment of instrumented particles to flow hydrodynamics. Earth Surface Processes and Landforms, 46(12), 2448-2465.
[3] Al-Obaidi, K., & Valyrakis, M. (2021). A sensory instrumented particle for environmental monitoring applications: Development and calibration. IEEE Sensors Journal, 21(8), 10153-10166.
[4] Valyrakis, M., Diplas, P., & Dancey, C. L. (2011). Prediction of coarse particle movement with adaptive neuro‐fuzzy inference systems. Hydrological Processes, 25(22), 3513-3524.

How to cite: Mavris, I. and Valyrakis, M.: Towards Enhancing River Bed Stability Assessment: A Comparative Study of LSTM, GRU, and Transformer Predictive Models, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2032, https://doi.org/10.5194/egusphere-egu25-2032, 2025.

The increasing frequency and magnitude of extreme weather events across the Earth's surface results in increasing pressure for living organisms and their habitats, including those in aquatic ecosystems. The main focus of this study is on the resilience of Mediterranean mussels (Mytilus galloprovincialis) against pronounced hydrodynamic stresses that may be experienced more frequently compared to the past. These mussels can be typically found in Mediterranean coasts and estuaries (such as in Greece, Spain, Italy, and Portugal), and they are also extensively farmed in the open sea using aquaculture practices. As such, they are of particular interest given their economic significance for Mediterranean countries, as well as their ecological role (offering significant ecosystem services as "ecosystem engineers", such as coastal protection).
The hydrodynamic stress of Mediterranean mussels is herein assessed indirectly using appropriately designed wave-flume experiments and analyzing video observations of the effects of wave motions of different characteristics on the Mediterranean mussels. For these experiments we embed specialised sensors to these mussels so they can record even minute displacements and changes in their orientation [1, 2]. Specifically, small, medium, and large mussels are exposed to two different configurations (similar to earlier studies [3]) on the surface of an artificial seabed, over which different wave fields are traversing. The movement of individual mussels was visually evaluated under varying wave intensities, transitioning from high to low energy and vice versa. These observations aim to determine the conditions and orientations under which these organisms drift relative to the wave flow direction or remain practically undisturbed. In the context of climate change and its impact on marine environments, this study may provide valuable insights into efforts to protect endangered marine species and enhance strategies for safeguarding aquaculture crops against damage caused by storms or significant wave fields.

References
[1] AlObaidi, K., & Valyrakis, M. (2021). Linking the explicit probability of entrainment of instrumented particles to flow hydrodynamics. Earth Surface Processes and Landforms, 46(12), 2448-2465.
[2] Al-Obaidi, K., & Valyrakis, M. (2021). A sensory instrumented particle for environmental monitoring applications: Development and calibration. IEEE Sensors Journal, 21(8), 10153-10166.
[3] Curley, E.A.M., Valyrakis, M., Thomas, R., Adams, C.E., & Stephen, A. (2021). Smart sensors to predict entrainment of freshwater mussels: A new tool in freshwater habitat assessment. Science of the Total Environment, 787, 147586.

How to cite: Karagianni, E. and Valyrakis, M.: Resilience of Mediterranean Mussels to Hydrodynamic Stresses: Insights for Climate Change Adaptation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2045, https://doi.org/10.5194/egusphere-egu25-2045, 2025.

Gravity flow is a key sedimentary process in deep-lacustrine environments, with transitional flow deposits commonly occurring in both distal and proximal zones of the turbidite systems. These deposits are crucial to understanding the sedimentary dynamics of fine-grained deep-water sediments. The transitional deposits between turbidity currents and mud-rich debris flows are particularly important for advancing our understanding of fine-grained sedimentation processes and have significant implications for unconventional oil and gas exploration.

The aim of this study is to describe transitional-flow facies, interpret their flow evolution and depositional processes, and assess their impact on the differential accumulation of organic matter in a fresh-water syn-rift deep-lacustrine system. Data were collected from the 111.39-m-thick Eocene  lacustrine oil-prone source rock succession, penetrated by the two wells in the Qibei Sub-sag, Bohai Bay Basin, China. Nine sedimentary facies were identified in the studied fine-grained succession, with various internal sedimentary structures (e.g., ripple cross lamination, low-angle cross lamination, wave lamination, parallel lamination, graded structure, deformed structure, and homogeneous structure) reflecting the dynamics of sedimentary processes in a deep-lacustrine depositional lobe distal environment. Millimeter-scale logging defined 5 bed types based on 2383 measured and recorded beds, with inferred transitional flow deposits exhibiting distinctive stacking patterns, from coarser grained turbidites to fine-grained debrites. A wide range of transitional-flow facies are recognized and can be assigned to turbulence-enhanced transitional flow, lower transitional plug flow, upper transitional plug flow and quasi-laminar plug flow. Despite the predominance of finning upward grain size trends, sedimentary structures in these heterolithic deposits may stack in varying orders, reflecting different flow dynamics.

The vertical facies trends of transitional flow deposit provide insights into the longitudinal flow evolution of flows, which were initially turbulent, but became increasingly laminar through deceleration and fine-grain entrainment. The assimilation of the lake-bottom mud into the density flows likely played a key role in modulating flow turbulence, helping to explain the common occurrence of transitional-flow facies indicated by sedimentological features such as sheared flame structures and deformed mud intrusions, which suggest interaction between the flow and the muddy lake floor.

Lacustrine organic matter was delivered to the lake floor by continuous settling, whereas terrestrial organic matter was transported via sediment density flows. The deep-lacustrine background mudstone is dominated by Type II₁ kerogen, whereas the quasi-laminar plug flow mudstone is dominated by Type II₁ and II₂ kerogen, turbulence-enhanced transitional flow and lower transitional plug flow mudstones are dominated by Type II₂ and III kerogen. These observations challenge the view that mud accumulates only from suspension fallout in distal basin-floor environments. This study suggests that composition, texture, and organic matter types of mud-dominated deep-lacustrine mudstones vary predictably in response to changes in depositional processes. The results have broader applicability to other deep-lacustrine sedimentary systems, highlighting the dynamic nature of transitional flows. Detailed microtextural and compositional analysis, combined with rigorous geochemical parameters, is essential for the understanding of the source-rock potential of basinal mudstones and fine-grained organic-rich sediments more general.

How to cite: Wang, J., Zhao, J., You, Z., Pu, X., Liu, K., Zhang, W., Shi, Z., Han, W., and Wang, Z.: Flow transformation processes recorded in the Eocene early syn-rift deep-lacustrine fine grained sedimentary rock in the Qibei Sub-sag, Bohai Bay Basin, China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3094, https://doi.org/10.5194/egusphere-egu25-3094, 2025.

This study aims to simulate the sedimentary processes of marine (lake) to terrestrial transitional clastic rocks and quantitatively analyze the impact of geological control factors on stratigraphic integrity. Most sedimentary strata exhibit discontinuities of different scales, represented by both temporal and spatial incompleteness. Defining and quantitatively characterizing "stratigraphic integrity" is of great importance for accurate stratigraphic correlation, reconstructing the depositional history of geological periods, and guiding oil and gas exploration.

2D physical water tank experiments can realistically simulate geological processes such as erosion, transport, deposition, and reworking of clastic materials. These experiments allow for the calculation of stratigraphic integrity at any given location. In this study, a narrow 3D water tank was used to approximate the 2D sedimentary processes, simulating the entire sedimentary sequence of marine (lake) to terrestrial transitional clastic rocks and calculating stratigraphic integrity.

A transparent glass water tank (1.5m×0.5m×0.05m) was chosen as the experimental setup. Based on a thorough review of relevant literature, multiple sedimentary bottom shapes were designed to replicate different real-world geological depositional environments. Specific time steps were set to quantitatively introduce different types of quartz sand, achieving visualization of the experimental results. A water level control curve was designed to change the water level over time, allowing for precise control of water height in the tank and effectively simulating the evolution of stratigraphic sequences. Finally, based on the experimental data, stratigraphic integrity was calculated for various depositional environments, enabling further analysis of the experimental results.

The experimental results clearly reveal the evolution of stratigraphy and depositional sequence features, which closely match actual geological conditions. This indicates that the experiment can realistically simulate the sedimentary processes of marine (lake) to terrestrial transitional clastic rocks. From an overall perspective, erosion near the sediment source is more pronounced and frequent, while at the distal end, the strata remain more complete due to prolonged subaqueous conditions, and erosion is less noticeable. The depositional sequence shows a typical progradation pattern, with thin oblique and wavy bedding structures. Stratigraphic integrity studies show that the integrity increases from the proximal to distal end. A comparison of integrity at the same location shows that horizontal surface fluctuations have a much stronger impact on stratigraphic integrity than changes in the bottom shape, with frequency variations in the water level control curve having a greater effect than changes in amplitude.

This study uses 2D physical water tank experiments to simulate and reconstruct the sedimentary processes of marine (lake) to terrestrial transitional clastic rocks. It also quantifies the influence of geological control factors on stratigraphic integrity. The results demonstrate that both the sedimentary bottom shape and water level change curves affect stratigraphic integrity, with water level changes having a more significant impact. This research is the first to combine 2D water tank simulations with stratigraphic integrity control factors, providing innovative experimental methods and technical tools for sedimentary physical modeling and stratigraphic integrity assessment.

How to cite: Fu, S. and Liu, J.: The Study of Stratigraphic Integrity of Marine (Lake) to Terrestrial Transitional Clastic Rocks Based on 2D Flume Experiments, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7676, https://doi.org/10.5194/egusphere-egu25-7676, 2025.

The EcoDaLLi project is an integrative initiative designed to contribute to the European Green Deal’s freshwater objectives by supporting the restoration, protection, and sustainable management of the Danube River Basin and its delta. As part of the broader mission "Restore Our Ocean, Seas & Waters by 2030," the project employs a systemic approach to ecosystem restoration through the implementation of innovative solutions and improved governance frameworks. By focusing on the Danube Basin, one of Europe’s most ecologically significant areas, EcoDaLLi aims to strengthen climate resilience, enhance biodiversity conservation, and promote sustainable water resource management. Additionally, Unitatea Executivă pentru Finanțarea Învățământului Superior, a Cercetării, Dezvoltării și Inovării (UEFISCDI) from Romania has awarded a special funding grant to support the present research.

A core scientific objective of the project is to document and analyze the dynamic behavior of the water surfaces in the Danube Basin. The present research relies on satellite radar imagery from the Sentinel-1 constellation, made available through the Copernicus Program. The radar data’s ability to penetrate cloud cover and record consistent surface reflections makes it highly suitable for long-term multi-temporal monitoring of water bodies, especially in a complex and variable environment such as the Danube Delta.

The initial phase involves the systematic collection of radar imagery, focusing on the VV polarization channel, which offers superior water isolation characteristics compared to other channels. In the second phase, a rigorous preprocessing workflow is applied to the raw imagery, including orbital corrections, radiometric normalization, and noise reduction. These steps are critical for ensuring data consistency and enabling precise extraction of water body extents. The processed data is then subjected to detailed geospatial analysis using advanced GIS tools, enabling the derivation of key hydrological metrics. These metrics include maximum and minimum water extent, presence and recurrence of water bodies, and seasonal variations.

The analysis will employ methodologies such as Continuous Change Detection and Classification (CCDC) to track and quantify spatial and temporal changes across the monitored lakes. Statistical models will further be used to correlate observed hydrological changes with climatic and environmental factors. The resulting datasets will provide a robust foundation for understanding the long-term hydrological dynamics of the Danube Delta’s lakes and their role in regional ecosystem functioning. Moreover, the results will offer guidelines for local and regional stakeholders, supporting evidence-based policy-making and adaptive management strategies.

Acknowledgments

This work was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS/CCCDI - UEFISCDI, project number PN-IV-P8-8.1-PRE-HE-ORG-2023-0089, within PNCDI IV.

How to cite: Toma, A. and Scrieciu, A.: Assessing Long-Term Water Dynamics in the Danube Delta Lakes using Sentinel-1 Radar Imagery, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8615, https://doi.org/10.5194/egusphere-egu25-8615, 2025.

Due global warming, rock glaciers were increased after the glaciers retreated rapidly. Rock glaciers, as an important indicators of mountain permafrost, play a critical role in mountain hydrology. The Gaizi River Basin, located in Pamir plateau and even has the Muztag-Ata (7,509m) and Gongger (7,719m) massifs. Comprehensive studies on distribution characterizations of rock glaciers in this region are currently in the incipient stages. Using Chinese high spatial resolution GF-2 Satellite images and Google Earth, a total of 56 rock glaciers were identified. Their spatial distribution and relationship with local factors were studied. Following the guidelines of the International Permafrost Association, out of the 56 rock glaciers, 9 are glacier-connected, 16 are glacier-forefield connected, 19 are talus-connected, and 12 are debris-mantled slope-connected. The rock glaciers are situated at slopes of 12゜–37゜ and elevations between 3380 m and 5320 m a.s.l. and predominantly facing north, northwest, or northeast (54.5 %). The average annual precipitation ranges from 26 mm to 350 mm and annual air temperature of the rock glaciers ranges from -13.5 ^。C to 3.9 ^。C. The rock glaciers can be used to quantify water storages and investigate the extent of permafrost and therefore carry significance in study their response to climate change.

How to cite: Liu, Y.: The distribution characteristics of rock glaciers in the Gaizi River Basin, China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12331, https://doi.org/10.5194/egusphere-egu25-12331, 2025.

Glaciers have retreated since the maximum extent of the “Little Ice Age” around c. 1850. The barren forefields provide a unique opportunity to study the development of an emerging ecosystem from its early stages to better understand successional mechanisms, community assembly and underlying filtering processes. While previous studies have primarily focused on the Central Alps, there remains a knowledge gap regarding succession for the forefields in the Northern Limestone Alps. The aim of this new monitoring platform is to gain a more comprehensive understanding of vegetation dynamics in the context of ecosystem succession in glacier forefields of this region. To this end, the chronosequence approach is applied across four glacier forefields, namely Hallstätter Glacier, Great Gosau Glacier (both in Dachstein mountains, Austria), Watzmann Glacier and Blaueis (both in Berchtesgaden Alps, Germany). Integrated, interdisciplinary methods are used for long-term monitoring and assessment of succession processes. From Vegetation monitoring which follows GLORIA guidelines, selected trait measurements, analysis of ancient DNA pools in ice lake sediments, abiotic site characterization including temperature recording and substrate sampling, to remote sensing methods we want to provide a whole picture of this dynamic environment. First results shows that species richness, abundance increase with age. However, these trends occur at a much slower rate than observed in the Central Alps. Initial trait analyses based on database entries revealed only a few clear patterns along the age gradient. In-depth analyses using trait field measurements are still underway. Additionally, environmental parameters seem to play a role in shaping succession, indicating that abiotic factors may significantly influence the pace and pattern of ecosystem development in the glacier forefields of the Northern Limestone Alps.

How to cite: Hecht, C.: Monitoring and research on succession in glacier forefields of the Northern Limestone Alps, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12335, https://doi.org/10.5194/egusphere-egu25-12335, 2025.

Geological sea-level proxies (e.g., fossil intertidal or foreshore deposits) preserve crucial data that enable the reconstruction of historical sea-level fluctuations. This information is essential for assessing the extension and volume of ice sheets during previous warm periods.

The work aims to present the results of a morpho-stratigraphic field campaign conducted along the southern Brazilian coast, from Osório (Rio Grande do Sul) to Paranaguá (Paraná). A classical geological and geomorphological approach was coupled with a literature review of the geological sea-level proxies related to Marine Isotope Stage (MIS) 5 from the coast of Uruguay to São Paulo. Samples from shallow-water marine sand and aeolian deposits have been analysed using granulometric and micropaleontological methods, in addition to direct dating with the Optically Stimulated Luminescence (OSL) technique. The elevation of each proxy was measured with centimetric precision using a GNSS RTK station and referenced to the local geoid model (MAPGEO2015), with an associated error margin of only a few centimetres.

Preliminary findings indicate that vertical land movements, both associated with glacial isostatic adjustment and sediment isostatic rebound, may have played a key role in the accumulation of Late Pleistocene marine and aeolian deposits, positioning them several meters above sea level at odds with global mean sea level position.

This presentation contributes to the WARMCOASTS project, which received funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement n. 802414).

How to cite: Cerrone, C., Lämmle, L., Perez Filho, A., Scicchitano, G., Jovane, L., Tagliaro, G. T., Mitrovica, J. X., Stocchi, P., and Rovere, A.: Pleistocene morpho-stratigraphy and vertical land motions on the South Brazil-Uruguay coastal plain, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12417, https://doi.org/10.5194/egusphere-egu25-12417, 2025.

Accurate assessment of coastal vulnerability is crucial for effective coastal risk management, especially in the context of increasing human pressure. One common approach to evaluating coastal erosion risk involves the use of geomorphological-based indices. These indices typically combine various physical factors such as: shoreline changes with historical and recent trends in coastline movement (erosion or accretion); dune and beach geometry (slope, dune height, and width); presence and type of vegetation, which can stabilize or destabilize the coastline; coastal infrastructure. the presence and type of human-made structures, such as seawalls and groins, which can impact coastal processes. These factors are often assigned weights or ranks to create a vulnerability classification, allowing for the identification of areas at higher risk of erosion. This approach provides a valuable framework for understanding the inherent susceptibility of a coastline to erosion. However, it is important to highlight that this is a simplified representation of complex coastal processes. Geomorphological indices offer a valuable tool for initial assessments of coastal vulnerability. Nevertheless, they should be used in conjunction with other data sources and analyses to gain a more comprehensive understanding of coastal processes. This study investigates coastal vulnerability along a coastline in Basilicata, southern Italy. The region faces significant coastal erosion due to a combination of natural factors and human impacts. To assess vulnerability, the study employs a multi-scale approach based on:  i) Coastal Erosion Susceptibility Index (CESI), this index evaluates the inherent susceptibility of the coastline to erosion based on factors like shoreline changes, dune and beach geometry, and vegetation. The results identified "hotspots" – areas with the highest level of susceptibility of coastal erosion; ii) High-resolution LiDAR Surveys, Unmanned Aerial Vehicles (UAVs) equipped with LiDAR sensors were used to create detailed 3D models of the coastline. By comparing LiDAR data from 2013 and 2023, we quantified the extent of coastal erosion and identified specific areas of significant change. This study demonstrates the effectiveness of integrating spatial data derived by indices with high-resolution LiDAR data for comprehensive coastal vulnerability assessment. This approach provides valuable insights for coastal managers in developing effective adaptation strategies to address the challenges posed by coastal erosion in the context of climate change and sea-level rise.

Founded by: Progetto PE 0000020 CHANGES, - CUP [B53C22003890006], Spoke 7, PNRR Missione 4 Componente 2 Investimento 1.3, finanziato dall’Unione europea – NextGenerationEU

How to cite: Minervino Amodio, A., Corrado, G., Di Paola, G., Rizzo, A., and Gioia, D.: Investigating Coastal Erosion Hotspots: A Multiscale Approach applied along the Basilicata Ionian coast (Southern Italy), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13498, https://doi.org/10.5194/egusphere-egu25-13498, 2025.

Coastal Zone Management Act (CZMA) areas in the United States are critical regions where coastal development and environmental conservation converge. Over 50 years, the CZMA has established a federal framework for state-level coastal management, fostering resilience to dynamic challenges. However, these regions increasingly face compounding risks from hazards such as sea-level rise, storm surges, and extreme precipitation, compounded by socio-economic vulnerabilities and geomorphological dynamics.

This study develops a geospatial framework for multi-hazard risk assessment in CZMA areas, integrating geomorphic and sedimentological characteristics with high-resolution datasets and socio-economic indicators to compute a detailed risk index. High-resolution datasets, including satellite-derived shoreline positions and wave and tidal records, are integrated with advanced geospatial and machine learning models, to enhance spatial and temporal projections. Future climate scenarios (2030, 2050, 2100) from CMIP6 datasets are used to assess long-term impacts of sea-level rise and extreme events, with scenario-based modeling addressing uncertainties across different emissions and socioeconomic pathways.

Preliminary findings reveal significant heterogeneity in risk distribution across CZMA areas, with low-elevation coastal plains, deltas, and lagoons identified as the most vulnerable due to geomorphic sensitivity and several challenges to protect them. Our comprehensive map highlights hotspots where erosion, flooding, and socio-economic disparities converge, enabling tailored adaptation strategies. This research bridges policy and science by integrating CZMA legal frameworks with geospatial and technological innovations, offering a scalable and transferable methodology for assessing and managing coastal multi-hazard risks globally.

How to cite: Poudel, S., Bista, S., and Talchabhadel, R.: Multi-Hazard Risk Assessment in CZMA Areas: A Geospatial Framework Integrating Future Climate Projections, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14644, https://doi.org/10.5194/egusphere-egu25-14644, 2025.

Interplay between environmental drivers and antagonistic biotic interactions shape the niche of species. Understanding the extent to which species retain parameters of their ecological niches amid long-term environmental changes is crucial for numerous palaeoecological inferences applicable to conservation efforts, sequence stratigraphic reconstructions, and macroevolutionary theory. 

The Venus nux association of the Arda and Stirone River sections (Early Pleistocene, western Emilia, northern Italy) has been here analyzed from a systematic and a paleoecological point of view, resulting in the identification of 23 mollusc taxa. As the majority of the retrieved taxa is represented by living species, a comparison between their fossil and present-day environment has been carried out, focusing also on the Venus nux association during the Pliocene of the same region. This research aimed to assess whether the overall bathymetric range and dominance of the bivalve Venus nux have changed over the last 5 million years in the Adriatic basin. Preliminary results indicate a shift in the ecological niche of this common species during a time marked by increasingly pronounced climatic oscillations.

Indeed, currently, V. nux is rarely retrieved in the Adriatic basin, but it is common in the Alboran Sea and the Ibero-Moroccan Gulf (southern Spain), where it thrives in muddy to muddy-sandy substrates at depths between 30 and 350 meters (Salas, 1996), but typically is abundant within 60 and 120 m depth ranges. Conversely, during the Pliocene and Pleistocene geological intervals, V. nux was common in the sedimentary successions of the Adriatic Basin, though it exhibited dominance at different depths and a potentially different bathymetric range. Specimens of V. nux from the Lower Pleistocene Arda and Stirone River sections reveal a shallower bathymetric distribution (20-40 meters of water depth), as evidenced by the co-occurrence in the mollusc association of shallow-water species, like Mytilus edulis and Ostrea edulis. During the warm Pliocene (Zanclean-Piacenzian transition), its bathymetric distribution was slightly deeper than in the cold Early Pleistocene, possibly mirroring current conditions. Although further detailed studies are necessary, it seems that over the past few million years, this species has changed its niche parameters, possibly due to climate shifts.

Salas, C. 1996. Marine bivalves from off the southern Iberian Peninsula collected by the Balgim and Fauna 1 expeditions. Haliotis 25: 33–100.

How to cite: Crippa, G., Chiari, A., Lombardi, M., and Scarponi, D.: The Venus nux association during the Early Pleistocene of the Adriatic Sea: a comparative analysis with its Pliocene and Recent distribution, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16446, https://doi.org/10.5194/egusphere-egu25-16446, 2025.

The exploration of seabed topography is of paramount importance for a wide range of scientific and environmental applications. In deep water, sonar or multibeam technology among others are commonly used to map details of the sea floor, but applying these techniques in shallow waters is challenging due to the complex nature of the submerged terrain. Moreover, these techniques are costly and not accessible for small-scale projects. In recent years, underwater photogrammetry emerged as an effective solution for shallow water bathymetric mapping, bridging the gap between land topography and deep-water bathymetric measurements. Photogrammetry also enables a 3D or 4D visual representation of the submerged terrain, habitats, and objects.

Our research proposes a novel approach applying underwater photogrammetry to generate a 3D model of submerged terrain in shallow-waters over rocky coastline. Using underwater photographs and advanced land surveying techniques, we successfully generated a high-resolution, georeferenced 3D model with detailed geospatial maps covering 162 m² at depths ranging from 1 to 5 meters below sea surface of a submerged upper subtidal zone of a rugged, rocky-coast landscape.

The proposed method offers a practical and affordable tool for shallow water bathymetric mapping over subtidal zones in rocky coasts, providing scientists with geospatial maps, measurements and visual representations for applications in marine research, coastal management, habitat monitoring, or underwater archeology.

How to cite: Elias, A. R. and Khalil, A.: 3D Mapping of Submerged Landscapes: A Cost-Effective Approach to Shallow-Water Bathymetry Using Underwater Photogrammetry, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17381, https://doi.org/10.5194/egusphere-egu25-17381, 2025.

Quantitative analysis of drainage networks is one of the most used approaches for the investigation of the response of landscape to tectonic forcing and crustal deformation in different geodynamic setting. Recently, river profile inversion has largely been used for the reconstruction of spatial and temporal distribution of uplift in tectonically-active landscapes. The calibration of the erodibility coefficient of the river profile is particularly effective in coastal landscapes, due to the diffuse presence of independent geomorphic markers of the tectonic uplift such as the marine terraces. In this work, we estimated the uplift history of a large sector of the Ionian sector of South-Apennine chain by inverse modelling of river profiles. The landscape is dominated by the presence of several well-preserved orders of marine terraces, which are deeply incised by a trellis-type fluvial net. Several factors such as uniform lithology and well-constrained chronology of several orders of marine terraces provided a favourable setting for the robust application of the modeling of river profiles. The study area includes a large sector of the Ionian coast between Taranto and northern Calabria. southern Italy. From a geological viewpoint, the studied catchments transversally drain the outer zone of the chain to the south and the foredeep-foreland system to the north. Middle Pleistocene deformation in the external sector of the chain has been already demonstrated while the late Quaternary activity of the frontal thrust belt is more debated. Our reconstruction of the spatial and temporal increase of uplift rates to the south can contribute to unravel the recent/active deformation along the buried front of the chain.

How to cite: Gioia, D., Cerrone, C., Corrado, G., De Santis, V., Minervino Amodio, A., and Schiattarella, M.: Uplift history of the Taranto Gulf (southern Italy) from river profile inversion, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17790, https://doi.org/10.5194/egusphere-egu25-17790, 2025.

The Portuguese spatial planning legislation includes legal restrictions to land use in order to preserve the ecosystems. These restrictions are framed by the legal structure called National Ecological Reserve (NER), and have associated a cartographic representation. Among the land use protection areas included in the NER are the Areas of High Risk of Soil Hydric Erosion (AHRSHE). Our goal is to improve the models and derived cartography and to use the enhanced maps as a basis to test and apply new and more advanced technologies, data and methods.

Currently, AHRSHE are determined based on USLE. The computation of the LS factor in this equation has been a challenging issue and, since this action is a legal responsibility of the municipalities, we could face a situation where different municipalities use different methodologies and, eventually, the results being not comparable. Thus, efforts have being made in order to produce a common methodology to standardise and enhance the cartographic representation of the LS, namely, by improving its accuracy and precision and by harmonizing and making it compatible with the other USLE factors. For this purpose, several methods of LS computation have been tested to evaluate soil loss risk in different geomorphic contexts. Based on the test results USLE's second revision, RUSLE2 (USDA, 2008), was selected together with imposing a maximum value to unorganised runoff length (L).

The results of using RUSLE2 might be affected by the lack of information on detailed soil properties caused by different geomorphological contexts and the lack of resolution of the Digital Terrain Model (DTM) to accurately identify the AHRSHE. The lack of DTM resolution affects the slope values (S), the shape of the hydrographic network and, above all, the delimitation of the disorganized flow domain, where AHRSHE are mapped.

In order to reach an acceptable solution, tests were made with varying maximum unorganized runoff length (L) and using different formulas to determine S, according hillslope values and rainfall regime. The test results show that the more accurate LS is obtained when L is limited to 305 m and S is calculated according to slope thresholds: below and above 9% (Panagos, et al., 2015) or above 18% (Liu, 1994; 2002), and excluding areas where the USLE is not applicable, like plane surfaces, water, or surfaces with high slopes.

Another conclusion was that small resolution DTM are inappropriate which lead us to use in the tests a 10m pixel DTM. Even so, and in order to prevent unjustified land use restrictions, we suggest the need to validate the results (by sampling), at least in specific geomorphologic contexts. Otherwise, the likelihood to get biased results, with adverse practical effects, will be high.

The shape and accuracy of AHRSHE depend on the methodologies and georeferenced data used. Thus, we intend to use, in the near future, a very-high resolution DTM derived from aerial LiDAR and to work on the identification of differentiated geomorphological contexts in each municipality in order to further improve the AHRSHE mapping, which have substantial impacts in the NER.

How to cite: Silva, A. and Reis, R.: Criteria to Map Areas of High Risk of Soil Hydric Erosion in Portugal using USLE, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20437, https://doi.org/10.5194/egusphere-egu25-20437, 2025.

Anthropogenic global change and environmental degradation lead to not only declines in biodiversity but also the simplification of trophic webs and fundamental changes in biotic interactions as taxa are removed from ecosystems. These changes are currently playing out over time scales of decades and centuries. Still, it would be instructional to understand the relationships between biotic interactions, diversity, and environmental change through deep time. Here, focusing on cephalopods, we quantify the relationships between antagonistic interactions and estimates of diversity, origination rates, and extinction rates. We have compiled a database of antagonistic biotic interactions preserved on fossil cephalopods composed of 279 species occurrences and 148,846 specimens ranging in age from Silurian to Quaternary. Predation occurrences were sparse in the Paleozoic, with peaks in the Jurassic and Cretaceous. We constructed a Generalized Linear Model comparing predation frequency and parasitism prevalence (for samples whose n ≥ 10) to mean standing genus diversity and three-timer origination and extinction rates using data from the Paleobiology Database and the Shareholder Quorum Subsampling methodology available on the FossilWorks website. A significant positive relationship exists between the frequency/prevalence of antagonistic interactions and mean standing diversity. Origination and extinction rates both have significant negative relationships with antagonistic interactions with much higher coefficients than mean standing diversity. We interpret this to mean that the intensity of antagonistic biotic interactions is higher when diversity is elevated but, more importantly, stable. We think this reflects that many of these interactions are obligate and taxon-specific. Ongoing work will include proxy data for temperature and CO2 concentration. As with modern ecosystems, we see evidence for links between diversity loss and the simplification of trophic webs in deep time.

How to cite: Burman, Z., De Baets, K., and Huntley, J. W.: Biodiversity loss and the simplification of trophic webs: Lessons from cephalopods in deep time, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21258, https://doi.org/10.5194/egusphere-egu25-21258, 2025.

How to cite: Gkogkis, K. and Valyrakis, M.: Siphon-Enhanced Micro-Hydroelectric System: Harnessing Elevated Flow Rates for Improved Power Generation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2380, https://doi.org/10.5194/egusphere-egu25-2380, 2025.

This research explores the transport dynamics of floating macro-plastics in riverine environments using drones for monitoring. Controlled flume experiments were conducted to evaluate the roles of vegetation density and release position on the movement and retention of plastic debris. Aerial imagery (captured by a DJI Mini 3 drone) was analyzed to determine transport patterns, revealing that plastics released in central flow zones moved faster with lower retention, while those near densely vegetated riparian areas experienced slower transport and higher trapping rates.
The findings demonstrate drones’ effectiveness in monitoring plastic pollution, providing a practical alternative to traditional methods in areas difficult to access. These insights emphasize the critical role of riparian vegetation in influencing plastic movement and retention, offering opportunities to design interventions that target pollution hotspots [1,2]. The study highlights the promise of drone-based approaches in advancing our understanding of plastic transport processes and informs strategies to mitigate the environmental impacts of plastic waste. Future research could enhance these findings by integrating drone data with other monitoring systems and refining analytical techniques for natural environments.

References
[1] van Emmerik T, Roebroek CTJ, de Wit W, Krooshof E, van Zoelen C, Fujita Y, Bruinsma J, Treilles R, Kieu-Le TC, Elshafie A, Christensen ND, Biermann L, Hees J, Meijer LJJ (2023) Seasonal dynamics of riverine macroplastic pollution, Nature Water, 1, 51-58
 
[2] Valyrakis M, Gilja G, Liu D, Latessa G (2024) Transport of Floating Plastics through the Fluvial Vector: The Impact of Riparian Zones, Water, 16, 1098

How to cite: Kaloudis, G. and Valyrakis, M.: Harnessing Aerial Imaging Techniques to Monitor the Transport of Floating Macro-Plastics in Fluvial Systems, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2558, https://doi.org/10.5194/egusphere-egu25-2558, 2025.

Lacustrine organic-rich Eocene mudstones are well developed and demonstrates significant exploration potential for shale oil in the Qibei Sub-sag, Bohai Bay Basin, China. However, their oil content displays strong heterogeneity, which poses challenges for effective exploration and development. Diagenesis implicates compaction, cementation, dissolution/re-precipitation processes that raises critical questions regarding reservoir quality and oil-bearing heterogeneity.

Integrated high‐resolution petrologic analysis, organic geochemistry, and pore throat structure characterization provide a powerful approach to investigate the diagenesis, reservoir and oil-bearing characteristics. The 50 samples were collected from the 111.39-m-thick Eocene the first Sub-member of the third Member of the Shahejie Formation lacustrine oil-prone source rock succession penetrated by the two wells in the Qibei Sub-sag. Six typical lithofacies were identified: laminated medium-grained calcareous shale, laminated fine-grained mixed shale, thin-bedded fine-grained mixed mudstone, thin-bedded medium-grained mixed mudstone, massive medium-grained mixed mudstone, and thin-bedded coarse-grained felsic mudstone.

The micritic calcite laminae formed during the sedimentary stage underwent recrystallization during the early to middle diagenetic stages, transforming into granular sparry calcite. Potassium feldspar dissolution and clay mineral transformation resulted in the formation of authigenic albite and quartz. These diagenetic processes promoted the development and preservation of intercrystalline/interparticle pores. As a result, the laminated medium-grained calcareous and laminated fine-grained mixed shale reservoirs exhibit superior reservoir properties, primarily characterized by interparticle pores, intercrystalline pores, clay mineral-associated pores, and bedding fractures. With a median pore throat diameter of 11.6 nm and an average porosity of 6.53%, these reservoirs are classified as Type I. The thin-bedded fine-grained mixed shale primarily develops clay mineral-associated pores and interparticle pores, with some bedding fractures. Its median pore throat diameter is 9.2 nm, and the average porosity is 5.56%, classifying it as a Type II reservoir. The thin-bedded medium-grained mixed and massive medium-grained mixed mudstones mainly develop interparticle pores and clay mineral-associated pores. These have a median pore throat diameter of 12.6 nm and an average porosity of 4.3%, classifying them as Type III reservoirs. In felsic mudstone, calcite cementation significantly reduced porosity during the early diagenetic stage. This results in the poorest porosity development in the thin-beded coarse-grained felsic mudstone, which has a median pore throat diameter of 15.9 nm and an average porosity of 3.26%, classifying it as Type IV reservoir.

The laminated medium-grained calcareous shale, laminated fine-grained mixed shale, and thin-bedded fine-grained mixed mudstone exhibit relatively high oil content and OSI values. The average oil content values are 2.48 mg/g, 2.64 mg/g, and 2.30 mg/g, respectively, and the average OSI values are 144 mg HC/g TOC, 163 mg HC/g TOC, and 168 mg HC/g TOC. These lithofacies are favorable for shale oil exploration and development. We suggest that addressing the challenges of mudstone diagenesis will significantly improve understanding and prediction of reservoir quality and oil-bearing heterogeneity in unconventional shale oil plays.

How to cite: Wang, J., Zhao, J., You, Z., Pu, X., Liu, K., Zhang, W., Shi, Z., Han, W., and Wang, Z.: Diagenesis, reservoir-quality, and oil-bearing heterogeneity of the Eocene deep-lacustrine mudstone in the Qibei Sub-sag, Bohai Bay Basin, China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2655, https://doi.org/10.5194/egusphere-egu25-2655, 2025.

        Glutenite Fans is one of the most favorable reservoirs for exploration and development in recent years and is widely distributed in the world. In recent years, major breakthroughs have been made in oil and gas exploration of glutenite fans in Luojia area in Luoxie 180 and Luo25 Wells. The Jiyang exploration area is a high mature exploration area in the east, which has entered the exploration stage mainly to search for subtle oil and gas reservoirs, and Glutenite Fans, as an important part of subtle oil and gas reservoirs, has become the most realistic and valuable exploration target at present.

       The Luojia area has a complex structural background, with the development of fault structures in the area, and the development of two sets of glutenite fans bodies of different origin, and the lithology difference is great. The diagenesis is complex and the calcareous intercalation is widely developed, which is of great significance for reservoir reconstruction.

        This paper takes the sand conglomerate of Es3 and Es4 members in Luojia area of Zhanhua Depression as the research object, synthesizes seismic, logging, core, analysis and test data, and carries out the research on the genetic types, sedimentary characteristics and diagenesis of the sand conglomerate controlled by different tectonic activities and provenance.

How to cite: yao, Y. and yang, Y.: Sedimentary Characteristics and Sedimentary Model of Glutenite Fans in Shahejie Formation, Luojia area, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2783, https://doi.org/10.5194/egusphere-egu25-2783, 2025.

The Permian Fengcheng Formation is an important hydrocarbon source rock development sequence and exploration sequence in the Junggar Basin. The Hashan tectonic belt, located on the northwestern margin of the Junggar Basin, is a large-scale thrust nappe superposed structure. Having undergone multiple tectonic movements and tectonic uplift and denudation, it has lost the stratigraphic distribution characteristics of a foreland basin. The Fengcheng Formation developed on multiple thrust tectonic steps, resulting in difficulties in stratigraphic correlation and unclear understanding of the distribution characteristics of the original sedimentary system and the development characteristics of favorable reservoirs. Therefore, clarifying the distribution laws and genesis of diagenesis and establishing a reservoir-forming model for high-quality reservoirs are of great significance for the effective sedimentary reservoir mechanism and the prediction of favorable gas-bearing areas in the study area.

How to cite: Li, Y.: Characteristics of Shale Reservoirs in the Permian Fengcheng Formation, Hashan Region , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3009, https://doi.org/10.5194/egusphere-egu25-3009, 2025.

Shale oil, as one of the most important unconventional oil and gas resources, has become the key target of oil and gas exploration in recent years. The Fengcheng formation in Mahu Sag is the best source rock in the sag, which has great potential for shale oil resources and is the key area for shale oil exploration in Junggar Basin.

Volcanic activity was frequent during the sedimentary period of Fengcheng Formation in the northern part of Mahu Sag. The sediments are mainly composed of tuff material of volcanic activity, evaporation material of caustic lake and a small amount of detrital material. The terrigenous detrital material mainly comes from long-distance transport, while the pyroclastic material is closely related to the proximal volcanic activity. The lithofacies development of shale is characterized by frequent overlapping of various lithologies, diverse combination types and rapid changes. The microfabric of fine-grained sedimentary rocks is characterized, the lithofacies types of fine-grained sedimentary rocks are summarized, and the assemblage relationship and development law of lithofacies in different environments are analyzed. The formation process of lacustrine fine-grained sedimentary rocks is discussed from the perspective of provenance supply and sedimentary dynamics, and the lithofacies development model of fine-grained sedimentary rocks is established. To a certain extent, the theory of lacustrine sedimentology is enriched and perfected, and it can also provide basic geological basis for tight oil exploration in this area.

How to cite: zhuang, Y.: The origin and lithofacies development characteristics of fine particle composition in the shale of the second member of Fengcheng Formation in Mahu Sag, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4626, https://doi.org/10.5194/egusphere-egu25-4626, 2025.

Abstract：Lake deltas are located in the complex zone of lake and river interaction, influenced by the dual effects of material exchange between the two. There are not only climate and water level influences, but also topography and geomorphology and waves and other lake hydrodynamic influences, resulting in a more complex lake delta evolution process. To explore the sedimentary characteristics and the impact of lake dynamics during different stages of delta development under the influence of coast current, the Muhuahe Delta in Daihai Lake is taken as the study object for modern sedimentary investigations. Through the analysis of high-precision satellite photos and the interpretation of profile information collected by UAV oblique photography, the sedimentary evolution of the delta in the study area was analyzed in detail. The results show that delta deposits are developed in the eastern gentle slope zone of Daihai, and the delta front subfacies are widely distributed. The profile shows that the sand bodies are affected by strong hydrodynamics, and a large number of wave-formed structures are developed and lateral migration is obvious on the plane. Satellite remote sensing data suggest the sedimentary sand bodies' development and distribution characteristics, indicating the control of coast current in the development and evolution of the delta. The delta is asymmetric, with well-developed sand dams at the delta front, growing parallel to the shoreline. Although influenced by provenance supply, during this period, the delta is controlled by littoral currents, and its expansion toward the lake basin is suppressed. Generally, coast current plays a significant role in modifying the plane distribution and scale of the delta front sand bodies. Reservoir heterogeneity is often generated due to different dominant hydrodynamic conditions, providing a reference for further exploration into the influence of coast current on reservoir development and distribution.

Keywords: coast current; gentle slope delta; sedimentary evolution

How to cite: Jiang, Y.: Sedimentary Evolution and Morphological Characteristics of Modern Lake Shoreline Delta under the Influence of Coast Current, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4736, https://doi.org/10.5194/egusphere-egu25-4736, 2025.

On the basis of core observation and description, multi-scale microscopic analysis and related reservoir physical property analysis, the petrological characteristics, reservoir characteristics and diagenetic characteristics of the Lower Jurassic Sangonghe Formation in the central area of Junggar Basin are systematically studied, and the diagenetic evolution sequence of the reservoir is further established. The results show that the reservoir in the studied interval has undergone three diagenetic processes: compaction, cementation and dissolution during its development and evolution after burial. The reservoir mainly goes through two stages: early burial compaction and late tectonic compression. There are various types of cementation, including carbonate, siliceous, clay mineral, gypsum and anhydrite. The overall intensity of dissolution in the reservoir is low, and it mainly develops in the interior or edge of easily soluble components such as feldspar and rock cuttings, and also develops in the edge of clay mineral bonding. Diagenetic evolution sequence of the reservoir in the study area is as follows: early calcite cementation - early chlorite cementation - acid dissolution/quartz enlargement/kaolinite cementation - illite cementation - gypsum/anhydrite cementation - late calcite cementation - iron calcite/iron dolomite cementation, mechanical compaction has developed in the whole burial evolution process.

How to cite: Guo, T. and Zhang, L.: Reservoir characteristics and diagenetic evolution of Lower Jurassic Sangonghe Formation in the hinterland of Junggar Basin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4748, https://doi.org/10.5194/egusphere-egu25-4748, 2025.

Coastal areas and related sedimentary environments are remarkable providers of valuable information about climatic changes and sea level oscillations. Lake Mert was formed as a shallow Black Sea coastal lagoon that contains various mixtures of marine and freshwater sources. This study presents sedimentological, geochemical and paleontological analyses of five sediment cores recovered from the lake which has been severely influenced by sea level change and local climate over the last 6.5 cal. ka BP. The environmental and climatic records obtained by multi-proxy analyses of the cores (µ-XRF, total organic carbon, stable isotope, pollen analysis and foram content) that are confidently correlated with other regional and global climate signals. In addition, Lake Mert also remains a challenge to identify and quantify dynamic changes in time on the coastal plain, thus, it possibly reflects hydrologic changes in the Black Sea since the middle Holocene. Analysis of lithology together with paleontological content of the studied cores reveal three main depositional units, each of them indicates varying areal facies distribution due to highly dynamic depositional settings in lake. Accordingly, the main lithofacies in the cores from bottom to top are defined as a relict lacustrine sediment older than 6.5 cal. ka BP (Unit 3), coastal and deltaic facies deposited between 6.5 to 4.5 cal. ka BP (Unit 2) and the younger lagoon-marine sediment (Unit 1).

Moreover, the correlation of well-dated sedimentological and geochemical proxies with the sea level and sea surface salinity records from the Black Sea allows us differentiate various phases of hydrologic changes due to connections with the Lake Mert during the middle-to-late Holocene. Our preliminary results suggest that the relict Mert Lake was first invaded by the Black Sea waters prior to 6.5 cal. ka BP, and then remained its fully connection until ~5.3 cal. ka BP due to subsequent inflow of the Mediterranean Sea via Bosporus. Furthermore, the decelerated sea level rise between 5.3 and 4.5 cal. ka BP gave rise to return semi-closed lagoon phase, restricting mixture with the Black Sea waters as inferred from stable oxygen isotope record. The later period, particularly after 3.5 cal. ka BP, was associated with more Euryhaline condition in the lake based on the paleontological content of the core sediment. The local climate changes are recorded in Lake Mert as a wet period between 6.5 and 4.5 cal. ka BP, a dry period between 4.5 and 2.9 cal. ka BP and wetter period after 2.9 cal. ka BP, respectively.

How to cite: Yakupoglu, C., Eriş, K. K., Karlıoğlu Kılıç, N., Yılmaz Dağdeviren, R., Nazik, A., Acar, D., Yakupoğlu, N., Sabuncu, A., and Kırkan, E.: Middle-to-Late Holocene Climate Change in Lagoon Lake Mert (NW Black Sea) and Its Hydrological Connection with the Black Sea: evidences from multi-proxy records , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4788, https://doi.org/10.5194/egusphere-egu25-4788, 2025.

Calcareous nannofossils are essential for age dating and studying environmental changes. These microscopic (1–20µm) calcitic cell-wall fossils coverings are abundant in most post-Paleozoic marine sedimentary rocks, providing a continuous stratigraphic record of biotic change. This study aims to document the stratigraphic occurrence of calcareous nannofossils at the wide-spread shallow marine carbonates of related to the Qom Formation in the Nargesan, Band, and Qaleh-Gabri sections, southeast of Kerman province (East of Central Iran Basin). Samples were collected at 50-100cm intervals from the marly parts of the section to basal part of the Upper Red Formation. To preserve the small-sized coccoliths, samples were processed using simple smear slide method. The prepared slides were examined with an Olympus BX53 light microscope using cross-polarized light at a magnification 1500-2000X. Gypsum and Quartz plates were used to identify various species. In this study employed the standard calcareous nannofossil zonation by Martini 1971 for the Oligocene sediments. The studied interval ranges from the Lowest Appearance (LA) of Sphenolithus ciperoensis species to the Highest Appearance (HA) of the Sphenolithus distentus, corresponding to the NP24 zone defined by Martini 1971. The calcareous nannofossil assemblages exhibit moderate diversity and frequency, with moderately to well-preserved nannofossil specimens observed, such as: Sphenolithus ciperoensis, Sphenolithus conicus, Sphenolithus moriformis, Zygrhablithus bijugatus bijugatus, Helicosphaera recta, Helicosphaera euphratis, Reticulofenestra bisecta, Reticulofenestra dictyoda, Reticulofenestra minuta, Cyclicargolithus floridanus, Cyclicargolithus abisectus, Coccolithus pelagicus, Braarudosphaera bigelowii, etc. According to the above-mentioned calcareous nannofossil assemblages, the age of late Rupelian can be assigned for the studied samples from the surface sections. Furthermore, the high-resolution study of calcareous nannofossils indicates a significant decrease in the abundance and diversity of Oligocene nannofossils, mirroring trends observed at other low and middle latitudes sites. This record of calcareous nannofossils and bioevents provides valuable insights into the paleoenvironments of thatperiod. This research marks the first report of nannofossils from shallow-water carbonates (related to the Qom Formation) from Jiroft-Kerman area.

References

Martini, E. (1971) Standard Tertiary and Quaternary Calcareous Nannoplankton Zonation. Proceedings of the 2nd Planktonic Conference, Roma, 1970, 739-785.

How to cite: kiani shahvandi, M., Parandavar, M., and Heinz, P.: Investigation of shallow-water carbonate distributions related to the QomFormation in distant sections of the type area, southeast of Kerman, Iran: insight to calcareous nannofossils, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7029, https://doi.org/10.5194/egusphere-egu25-7029, 2025.

Deep marine carbonate rocks in the Tarim Basin, Northwest China, have significant burial depths, ancient ages, and complex diagenetic evolution. Multi-stage tectonic activities and periodic sea-level changes create unconformities that expose carbonate rocks, resulting in interlayer, syn-sedimentary, and epigenetic karst systems. These processes, along with host rock composition and faulting, shape carbonate reservoir distribution and properties. Dissolution is most intense in shallow water grainstones and packstones, where fracturing enhances fluid flow, serving as both reservoirs and migration pathways. Consequently, carbonate reservoir characteristics in the northern Tarim Basin vary systematically from north to south, shaped by variations in unconformity size, diagenetic patterns and fault activity intensity, reflecting the basin’s evolution from deposition to deep burial. In the Yakela area, the northernmost region, significant uplift and erosion have exposed Cambrian, sometimes even Sinian bedrocks beneath Cretaceous layers, forming buried hill dolomite reservoirs. Moving south to the Tahe area, a paleokarstic erosion zone has developed large-scale dissolved fracture-cavity reservoirs due to the combined effects of faulting, surface karstification, and river system development near the base Carboniferous erosion surface. Further south, in the Tahe slope zone, reservoirs are shaped by a combination of dissolution and faulting, with bedding-parallel dissolution pores and enlarged fractures becoming more prominent as proximity to the paleoerosion surface decreases. This reflects a decrease in karstification intensity and an increase in fault-induced fluid pathways. In the Shunbei area where marine carbonates are deeply buried, structural features such as fault slip surfaces and open fractures dominate reservoir formation, with tectonic activity and fluid flow through fractures driving diagenetic alterations. The spatial variations in diagenetic pathways—from initial deposition and uplift in the north to deep burial in the south—highlight the interplay of dissolution, tectonics, and fluid migration across varying depths and time scales, providing insights into the mechanisms that control carbonate reservoir formation and evolution globally.

How to cite: Fan, T.: Orderly variations in the spatial and geological characteristics of carbonate reservoirs in the northern Tarim Basin, China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7580, https://doi.org/10.5194/egusphere-egu25-7580, 2025.

    A 39,000-year record of sedimentary environmental changes, based on high-resolution grain size and diatom records from core ZK13-22, in the eastern shore of the Dongzhaigang harbor, Hainan Island, make it possible to study the relationship between environmental changes in the study area and the sea level changes in the South China Sea.

    The results show that during the period from 39.4 to 15.3 ka B.P., the grain size of the core ZK13-22 sediments was relatively coarse, and no diatoms were observed in the corresponding layer, suggesting that the study area was mainly in a terrestrial environment. Between 15.3 to 10.3 ka B.P., the grain size decreased during post-glacial period, the plankton species (Cyclotella striata and Paralica sulcata), which are marine species living in estuarine areas, was above 70% on average. The content of the benthic species Nitzschia cocconeiformis reached as high as 17%, indicating a rise in sea level in the South China Sea, marine waters intruded onto the Dongzhaigang harbor and reached the core site, and during this transgressive interval, the study area changed into an intertidal environment. From 10.3 to 7.6 ka B.P., the sediment particle size reached its lowest value throughout the borehole, while the species diversity and abundance of diatoms peaked, dominated by eurythermal intertidal and coastal planktonic species, the core site generally showed a enhanced marine influence and reduced freshwater input, shallow marine environment developed in situ. Between 8.0 to 7.6 ka B.P., the content of Rhizosolenia bergonii peaked, suggesting that the sea water temperature and salinity were relatively high during this period, possibly related to the intensified warm currents in the region. Since 7.6 ka B.P., the grain size increased significantly, diatoms only appeared at 4.4 ka B.P.. During this period, the relative abundances of Cyclotella striata and Paralica sulcata in the sediments climbed to 29% and 26% respectively. This change indicates enhanced hydrodynamic conditions, increased riverine influence, and sea level fluctuating decreases. Correspondingly, the the core site gradually shifted to an estuarine-intertidal environment. During the period from 4.4 to 3 ka B.P., the sediment grain size increased sharply, the study area transitioned to a terrestrial depositional environment.

How to cite: Yang, X., Wang, C., Jiang, W., and Hu, D.: Environmental changes since 39 ka reflected by diatom in core sediments from Dongzhaigang Harbor, Hainan Island, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11788, https://doi.org/10.5194/egusphere-egu25-11788, 2025.

The built environment (BE) across various sectors faces significant challenges due to increasing deterioration, ageing infrastructure, extreme climatic conditions, rising urban populations, and limited financial resources [1]. Digital transformation offers the potential to revolutionize current practices for managing and sharing key information, improving decision-making processes and enabling more efficient and sustainable BE in the long term. However, despite recent advancements in technology, critical infrastructure systems within the BE continue to rely on traditional management approaches in terms of technology, organizational structure, and institutional frameworks. Consequently, they fail to fully leverage emerging technologies that could enable advanced resource and risk management through real-time data integration and enahnced analytical methods.

Adopting technologies associated with Infrastructure 4.0 (CI4.0) [2] can accelerate the digitalization of BE, with a particular focus on infrastructure systems. This study highlights the foundational elements of a next-generation BE designed to foster an interconnected and collaborative ecosystem focused on cities, infrastructure, and societies. Several case studies are explored, including large residential developments, transportation networks, and buildings, demonstrating the transformative potential of digitalization in delivering real-time information to stakeholders, thereby enhancing decision-making processes.

These efforts rely on the acquisition of real-time data from the environment to predict both current and future conditions of the BE. For instance, advanced microcontrollers are utilized to monitor the declining performance of ageing infrastructure over waterways and to measure flood levels in real-time. Datasets are processed on high-performance cloud-based systems, utilizing deep learning algorithms to forecast infrastructure conditions and climatic risks. In emergency scenarios, such as river overflows, flash floods, or infrastructure failures, the system generates timely alerts. Moreover, predictive models provide early warnings about infrastructure deterioration, enabling critical stakeholders to respond proactively and adapt societal operations accordingly.

References

[1] Michalis, P., Vintzileou, E. (2022). The Growing Infrastructure Crisis: The Challenge of Scour Risk Assessment and the Development of a New Sensing System. Infrastructures, 7(5), 68. https://doi.org/10.3390/infrastructures7050068

[2] Xu, Y., AlObaidi, K., Michalis, P. and Valyrakis, M. (2020). Monitoring the potential for bridge protections destabilization, using instrumented particles. Proceedings of the International Conference on Fluvial Hydraulics River Flow, Delft, The Netherlands, 7–10 July 2020; pp. 1-8. eBook ISBN 9781003110958.

How to cite: Michalis, P., Konstantinidis, F., Katika, T., Michalis, A., and Valyrakis, M.: Leveraging Digital-Physical Integration for Enhanced Infrastructure Management, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16062, https://doi.org/10.5194/egusphere-egu25-16062, 2025.

High mountain environments are disproportionately affected by climate change. Around the world, mountain glaciers are retreating, leaving unstable sediments behind. Thawing permafrost and changing rainfall conditions make many mountain slopes unstable and increase natural hazards. Plants colonize the newly available terrain, but also need to shift upslope to survive rising temperature, threatening biodiversity. What will happen in the future? Might unstable sediments and moving slopes limit plant colonization and shifts? Or can colonizing and shifting plants actually stabilize moving sediments and slopes? This depends on biogeomorphic feedbacks!

In this award lecture, I will take you on a journey through recent finding and advances in “mountain biogeomorphology”, the discipline investigating feedbacks between moving mountain slopes and dynamic mountain plants. Our journey will start in the front of retreating glaciers. Here, I will illustrate the strong biogeomorphic feedbacks between paraglacial geomorphic processes and vegetation succession, mediated by “ecosystem engineer” plants that not only stabilize moving moraine slopes but also promote periglacial landform development, soil formation and vegetation succession.

In a second part, I will evaluate the role of biogeomorphic feedbacks in a changing climate. Using a “biogeomorphic balance” concept, we will assess how biogeomorphic feedbacks can influence future slope movements, vegetation shifts, natural hazards and biodiversity in different scenarios. Finally, I will take you to the current research frontiers in mountain biogeomorphology. I will illuminate the yet not fully understood role of plant traits and sediment properties as key controls for biogeomorphic feedbacks. Subsequently, we will explore how increasing data availability and novel methods, including artificial intelligence (AI) techniques, can help to unravel biogeomorphic feedback mechanisms and dynamics. Thereby, mountain biogeomorphic research can advance understanding and mitigation of climate change impacts on high mountain environments.

How to cite: Eichel, J.: Feedbacks between moving mountain slopes and dynamic mountain plants, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16685, https://doi.org/10.5194/egusphere-egu25-16685, 2025.

Analysis of digital elevation models (DEMs) complements geological field observations by enabling precise identification of deformation signals in tectonically active mountain belts. In the broken foreland of the NW Argentinian Andes, active deformation is linked to the compressional reactivation of Mesozoic extensional structures. However, there are locations where this reactivation has not yet resulted in mappable surface ruptures or well-expressed folding above inferred tectonically active structures in the sub-surface. Instead, the deformation has remained subtle, with less noticeable geomorphic changes. In such environments, DEMs aid in identifying spatial patterns of tectonic activity by capturing subtle deformation signals related to hidden structures. Understanding such deformation patterns is essential as it reveals the spatial and temporal evolution of orogenic growth in a broken foreland, while also aiding seismic hazard assessment by identifying hidden blind thrust faults.

Here, we delineate zones of neotectonic deformation in the eastern piedmont of the Calchaquí Valley, a fault-bounded intermontane basin in the southeastern part of the Eastern Cordillera of NW Argentina. The study area spans latitudinally from Quebrada del Río Tin Tin in the north to Quebrada la Cruz in the south. We use the TanDEM-X 10 m dataset to select well-defined east-west flowing tributaries of Río Calchaquí that cut through the eastern piedmont of the valley. We analyze the longitudinal profiles of these streams, associated pediment surface profiles that are parallel to the streams and that reflect paleo-thalwegs, and fluvial relief characteristics.

We identify a previously unmapped NNE-SSW-trending deformation zone running almost parallel to and west of the Payogasta thrust, extending between Quebrada del Río Tin Tin and Quebrada los Arce. The maximum deformation associated with the suspected blind thrust driving this deformation is observed approximately 1 km upstream from the confluences of these east-west flowing tributaries with the Río Calchaquí. This deformation diminishes southwards from Quebrada los Arce towards Quebrada la Cruz. The deformation appears to shift eastward near Quebrada la Cruz, aligning with known faults. We note that no apparent warping is observed in the rivers’ longitudinal profiles, indicating that erosion of the riverbed has been removing the tectonic deformation signal, while the deformation is preserved by the deformed pediment surfaces. We also mapped fluvial terraces using aerial photos and high-resolution satellite images near the major streams. The longitudinal profiles of these Pleistocene terrace remnants closely align with the deformed pediment surface profiles, further confirming the presence of deformation in the identified zones on longer timescales.

Our observations in the field reveal that the terrace deposits associated with deformation between Quebrada del Río Tin Tin to Quebrada los Arce exhibit an average dip of approximately 3º to the east. This contrasts with the expected dip of 2-3º to the west, which aligns with the gradients of westward-flowing piedmont rivers. These findings offer further empirical evidence of deformation signals in the region and reveal that deformation within the Andean orogenic wedge is ongoing, which will ultimately lead to basin closure and fluvial re-adjustment due to protracted shortening.

How to cite: Pandey, A., Strecker, M. R., and Bookhagen, B.: Using DEMs to map subtle geomorphic expression of Quaternary deformation in the Eastern Cordillera of NW Argentina, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-574, https://doi.org/10.5194/egusphere-egu25-574, 2025.

Valley floors influence a range of environmental processes in mountain regions. For example, valley floors serve as a deposition zone for geomorphological processes occurring on hillslopes. Valley floors represent relative low points in the landscape, thereby affecting basin hydrology and influencing soil moisture in these locations. Valley floors also serve as important locations of organic carbon storage in soils and vegetation. While it has been recognized that valley floor widths in mountain regions often show high variability due to complex geology and geomorphology, few studies have quantified and analyzed values and controls of valley floor widths in these settings. Objectives of this study are to measure valley floor widths for three small tributary drainage basins in Kananaskis, Canadian Rockies and to analyze possible controls, including geology and geomorphology, on valley floor widths. First, delineation of valley floor extent for alluvial parts of the channel network in the three study basins is undertaken using GIS-based methods. Valley floor polygons consist of DEM grid cells that fall within a threshold height relative to the channel height. Next, valley floor widths are obtained by measuring width in a direction perpendicular to the channel for valley floor polygons along the entire channel network. The complex geological and geomorphological characteristics in our study region suggest that generalizations about valley floor widths relevant to larger, lowland drainage basins are not likely to be applicable for our study area. Upper Kananaskis Creek and Ribbon Creek basins show overall higher values of valley floor width relative to Porcupine Creek basin, likely due to their topographical positioning, which is expected to result in higher precipitation and discharge values and greater possible impacts of past glaciation. Results show a very high variability in valley floor widths along the channel network for all three study basins. Valley floor widths show distinct fluctuations between groups of below-average and above-average values in an upstream direction, with any particular group often persisting for a relatively short distance before a notable change in valley floor width is observed. Channel junction locations along the channel network are often associated with local increases in valley floor width for all study basins, although such increases sometimes only last for short distances. Bedrock lithology is found to influence valley floor widths in the study basins, with either below-average or above-average values being associated respectively with more resistant Palaeozoic formations or somewhat more erodible Mesozoic formations. Geological structures situated near channel networks are also shown to be a possible control of valley floor width in some situations. Parts of the channel network in Upper Kananaskis Creek basin and Ribbon Creek basin show evidence of glacial activity, with greater valley floor widths often found in these locations.

How to cite: Martin, Y. and Alvarez, H.: Variability of Valley Floor Widths in a Mountain Landscape, Canadian Rockies, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3833, https://doi.org/10.5194/egusphere-egu25-3833, 2025.

Photo bathymetry is the use of photogrammetry for the reconstruction of the underwater topography. The imaging systems are located above water and the optical rays go through two different media, air and water, which means the rays are refracted at the water surface according to Snell’s law. This refraction leads to a blur in the images and an error in the reconstruction of the topography, and represents today the main limitation to achieving high accuracy photo bathymetry. A 3D model of the water surface at the time of capture of the topography is therefore a prerequisite to correct the ray paths. Our method aims to solve the problem of simultaneous reconstruction of the water bottom and the water surface. In this contribution, we present the setup and the results of an experiment carried out in the measurement lab of TU Wien.

We have borrowed a complete camera rig from IfP Stuttgart. This setup is composed of four cameras and lenses, an Arduino Leonardo and the associated cabling. The Arduino serves as a controller and synchronizes the cameras by sending a trigger signal in user-definable intervals via a cabled USB connection. Two cameras are used to capture the water surface, looking obliquely from the side, and the other two to capture the water bottom, looking nadir from above. A water tank is filled with water and two layers of stones to obtain a textured topography. Finally, we use an indoor fountain pump to create a dynamic water surface. Prior to the data acquisition, we first installed an array of coded photogrammetric targets on the floor, walls, and measurement pillars in the corner of the lab and measured the 3D coordinates with sub-mm precision with a total station. These targets served as control and check points in the bundle block adjustment. In a second step, we measured the topography of the empty water tank with a conventional image block using a Structure-from-Motion and Dense Image Matching approach to obtain a reference model that will serve as validation.

How to cite: Gueguen, L.-A. and Mandlburger, G.: Lab experiment for simultaneous reconstruction of water surface and bottom with a synchronized camera rig, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6836, https://doi.org/10.5194/egusphere-egu25-6836, 2025.

Sediment transfer from hillslopes to valley floors represents a major component of the sediment routing regime in mountainous environments. Valley floors are connected to a range of physical, chemical and biological processes, including hydrological flow routing, soil moisture, vegetation growth and organic carbon storage. The degree of connection between hillslopes and valley floors depends on variables that affect geomorphic process operation on hillslopes, including slope morphology, land cover, rock and/or soil characteristics, and precipitation regimes. This study measures and analyzes the degree and variability of hillslope-valley floor coupling along channel networks in small drainage basins in Kananaskis, Canadian Rockies. First, key morphometric and land cover variables derived from DEM and satellite-based data are analyzed for study basins. These variables influence hillslope sediment transfers to local valley floors. A large proportion of landscapes in tributary study basins is defined as 1^st order or 2^nd order sub-basins with slope gradients often in the range of 30 degrees to 60 degrees. These landscapes have significant potential for mass movements. Geology and geomorphology are shown to influence the complex arrangement of landscape morphology and land cover within study basins. Ribbon Creek and Upper Kananaskis Creek basins show a greater extent of steep, rock areas compared to Porcupine Creek basin. Next, parts of surrounding hillslopes that have potential for sediment transfer to valley floors are identified. Significant breaks in slope gradient on hillslopes above local valley floors are shown to limit the hillslope length with potential to connect with the valley floor. Lower-order stream links show a higher percentage of surrounding hillslopes that are coupled with valley floors relative to higher-order stream links. Next, coupled parts of landscapes in study basins are classified into categories of mass movement potential based on primary controlling variables (e.g., slope gradient, land cover). Mass movement potential within coupled parts of the landscape determines the degree of hillslope-valley floor coupling. Maps show significant variability in mass movement potential along channel networks in study basins. Variability in hillslope-valley floor coupling results from the complex geological and geomorphological controls on landscape characteristics in this region. Glacial oversteepening of hillslopes is more notable in Ribbon Creek and Upper Kananaskis Creek basins and results in more landscape areas with a high degree of hillslope-valley floor coupling compared to Porcupine Creek basin. Parts of channel networks with resistant lithology typically show relatively uniform, steep hillslopes, with limited buffers between hillslopes and valley floors. In contrast, areas with less resistant lithology often display lower slope gradients and more buffers that limit hillslope coupling with valley floors. Finally, parts of the landscape with overall greater heterogeneity in bedrock lithology show smaller and more complex-shaped units of hillslope connection with valley floors compared to areas with more uniform lithology.

How to cite: Warsmann, B. and Martin, Y.: Hillslope-Valley Floor Coupling Along Steep Mountain Channel Networks, Kananaskis, Canada , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7286, https://doi.org/10.5194/egusphere-egu25-7286, 2025.

Huolongtan is located in the east of Baisha Island, Penghu, Taiwan. It was formed by the 1986 typhoon and is the youngest sandbar island in Penghu. This study explores its changes at different time and space scales, focusing on the interaction between tropical typhoons and the northeast monsoon. The influence of its terrain.

In this study, multi-period UAV photogrammetry was used to analyze the erosion and sedimentation status before and after typhoons and northeast monsoons using a DSM of difference (DoD). Grain size analysis and marine meteorological data were combined to explore natural variation factors. The USGU Digital Shoreline Analysis System (DSAS) was used to analyze shoreline changes.

The research results show that the sandbar erosion and siltation responses showed different spatial trends during the three typhoons. The maximum wave height of Typhoon Koinu was 567 cm, and the volume of sedimentation was -7657.2m³, with a ratio of -0.03. During the passage of this typhoon, the wind was mainly from the north, causing accumulation on the south bank and erosion on the north bank, and its sand tail gradually swing south to change. During the northeast monsoon, the volume of sediments recovered, with a volume of 9048.5m³and an increase of 0.04, but the sandbar islands were eroded again in the late northeast monsoon. In addition, this paper found that the intertidal zone of several kilometers in the north would protect the terrain of the northern shore, and significant erosion would only occur with high wave heights or long-term monsoon waves. Comparison of the zero-meter contour lines shows that the main island of Huolongtan has a tendency to move southwest and sand tail has a tendency to move north. The maximum erosion of the coastline changes in the medium and short time intervals is 21.3m/y (end point rate (EPR)) and 8.2m/y (linear regression rate (LRR)); the maximum accumulation is 30.0m/y (EPR) and 16.4 m/y (LRR), and the Kalman filter was used to predict that the north bank would erode more landward and the south bank would advance toward the sea in 10 years.

The research results can be applied to the sustainable development of recreational areas and seabird habitats on Huolongtan sandbar under climate change and frequent extreme events. This will also help management units to adapt to climate change in a changing environment.

Keywords: UAV, Particle size analysis, DSAS, Coastal change

How to cite: Fang, C., Lu, C.-H., Yu, N.-T., and Ho, L.-D.: Spatio-Temporal Morphodynamics of Huolongtan Sandbar, Penghu islands Taiwan - Using Short-term Monitoring from 2020 to 2024, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15044, https://doi.org/10.5194/egusphere-egu25-15044, 2025.

Identifying the seismic signature of rivers (e.g., flow and bedload) is a significant challenge due to the varying responses of the investigation site and the hydrodynamic parameters controlling river streams during flood events. Moreover, environmental noise, such as wind and rain components, is not always easily distinguishable from the signal generated by river motion, given their overlapping frequency ranges.

We analysed the seismic signature of the Tagliamento River, located in Friuli-Venezia Giulia (Northeast Italy), recognised as one of the "last large natural alpine rivers in Europe." This river is characterised by significant water level rises and gravel sediment transport during extreme meteorological events. Using data from level gauges and pluviometric sensors alongside seismic stations installed along the river, we examined the relationship between increasing water levels, rainfall indices, and the amplitude of seismic waves recorded by seismometers during multiple flood events from 2018 to 2024.

Additionally, we performed detailed analyses, including cross-correlation, time-of-concentration calculations, and seismic signal polarisation, to better characterise river behaviour. This preliminary study aims to understand the seismic signals generated by the turbulent flow of the river and the transported bedload using the collected data. Subsequently, we propose to develop an empirical model for water level estimation, enabling the evaluation of hydrogeological hazards during upstream floods with the assistance of machine learning algorithms.

How to cite: Gangemi, M. V., Borzì, A. M., Cannata, A., Cannavò, F., Parolai, S., Spampinato, C., Zini, L., and Panzera, F.: Preliminary Seismic Signature Analysis of the Tagliamento River During Flood Events Using Machine Learning Algorithms, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-906, https://doi.org/10.5194/egusphere-egu25-906, 2025.

Seismic sensors, traditionally used in geophysical studies, are emerging as non-invasive tools for continuous wildlife monitoring by capturing seismic waves generated by animal locomotion. This novel approach opens new possibilities but also presents methodological challenges. In this study, we analyze seismic signals from African savanna species during locomotion and apply machine learning to classify species based on footfall signals. Utilizing the SeisSavanna dataset, which includes over 70,000 labeled seismograms paired with camera trap images, we identify distinct species-specific footfall patterns. Our analysis reveals that local site effects significantly influence signal frequency content. To address this, we trained machine learning models on data from multiple locations, achieving a balanced accuracy of 87% for elephants, giraffes, hyenas, and zebras at distances up to 50 meters, decreasing to 77% at 150 meters due to weaker signals and lower label quality. Importantly, the models generalize well to new stations if similar site conditions are represented in the training data. These findings highlight the potential of seismic monitoring to complement tools like camera traps and acoustic loggers, offering unique insights into wildlife behavior and expanding monitoring capabilities to silent species. To fully realize this potential, further methodological advances and larger datasets are necessary to establish seismic sensors as a robust tool for wildlife conservation.

How to cite: Steinmann, R., Nissen-Meyer, T., Cotton, F., Tilmann, F., and Mortimer, B.: Seismic Footsteps: Harnessing Machine Learning to Decode Wildlife in the African Savanna, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2842, https://doi.org/10.5194/egusphere-egu25-2842, 2025.

Fin whales, the second-largest animals on Earth, produce some of the most intense vocalizations in the animal kingdom. Monitoring these sounds using ocean-based hydrophones is crucial for studying their distribution and social behaviour, although obtaining real-time data remains challenging. In this study, we explore whether vocalizing near-coastal fin whales can be detected and located widely using onshore seismometers. By analysing publicly available data from existing seismic stations, we show that fin whale songs can be detected with onshore seismometers up to 5.5 km inland across various marine environments worldwide. Through the analysis of seismic wave properties, individual whales can be located and tracked.

Additionally, we demonstrate that citizen science seismometers, like the affordable and widely used ‘Raspberry Shake’ devices, can reliably detect fin whale songs. These instruments, often placed in coastal areas, offer a cost-effective and accessible approach to monitoring coastal fin whale activity in real-time. The discovery that human habitats are ensonified by fin whale song presents an opportunity to increase public engagement with marine life and opens new possibilities for global monitoring. Given that fin whales are threatened by noise pollution, shipping collisions, and entanglement in fishing gear, the use of terrestrial seismometers could help improve early warning systems and enhance datasets on near-coastal whale vocalizations. This study highlights the significant, untapped potential of seismic data for monitoring near-coastal fin whales on a global scale.

How to cite: Möllhoff, M. and Bean, C.: Onshore seismometers detect fin whale songs, unlocking new opportunities for coastal cetacean monitoring and public engagement, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4452, https://doi.org/10.5194/egusphere-egu25-4452, 2025.

Current methods employed to track the spatiotemporal evolution of ocean wave mainly include insitu buoys, numerical ocean wave modeling, and satellite altimetry. Each method has its own strengths and weaknesses in terms of spatial and temporal resolution. For example, buoys provide high temporal resolution, but lower spatial resolution compared to numerical wave forecast modeling and satellite altimetry.

This study explores an alternative method to investigate the feasibility of constructing an ocean wave monitoring system utilizing land-based seismic amplitudes. The proposed method relies on the correlation between secondary microseism amplitudes detected on land and their causative ocean wave heights. .

In this method, we implemented a supervised Artificial Neural Network (ANN) to quantify the nonlinear relationship between secondary microseism amplitudes recorded on land and the associated ocean wave heights.. The ANN was trained using seismic amplitudes data from seismic stations distributed across Ireland and Buoy data or numerical simulated ocean wave height data in the Northeast Atlantic. Subsequently, the trained ANN was utilized to estimate significant Wave Height (SWH) at specific location(s). The estimated wave heights exhibit a similar statistical distribution to in-situ wave height observations, with normally distributed differences. Since the approach is purely data-driven, its implementation is straightforward and holds potential as a reliable, low-cost operational tool.

The comparison between our results and the measured wave height data demonstrates a strong correlation, particularly for smaller wave heights, where the estimates show excellent accuracy. For larger wave heights, while the estimates are not as accurate, they still provide reasonably reliable approximations, highlighting the robustness of this  approach, across a range of ocean wave conditions.

How to cite: baranbooei, S. and Bean, C. J.: Monitoring Ocean Wave height in the Northeast Atlantic Using Terrestrially based microseism data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5217, https://doi.org/10.5194/egusphere-egu25-5217, 2025.

In April 2024, a M7.2 earthquake struck the east coast of the Taiwanese island near the city of Hualien. Being the largest earthquake in the region for more than 25 years, the Hualien earthquake offers a unique opportunity to study the landscape and subsurface response to strong ground motion. Extraordinarily high precipitations during the following monsoon season put additional pressure on the near-surface and subsurface hydrological systems. Here, we combine multidisciplinary environmental and hydrological datasets with seismological data products recorded by a network continuously active since 2016 around the Liwu River catchment. We analyse, for example, seismic velocity change time series (dv/v) or horizontal over vertical spectral ratios (H/V) to shed light on the mechanisms causing increased river discharge and changes in water composition following strong ground motion events. In the data, we not only find a strong response to the M7.2 earthquake but also clear evidence of seasonal variation corresponding to the biannual cycles in temperature and rainfall. This study will put further constraints on the reaction of aquifers and aquitards in mountainous environments to large earthquakes. Mountain freshwater reservoirs are a primary resource for the Taiwanese population and economy. Understanding its dynamics will shed light on the chances and limitations of its exploitation and sensitivity to climate change.

How to cite: Makus, P., Hovius, N., Turowski, J., and Chang, J.-M.: Investigating Modifications in the Hydrological System Following the M7.2 Hualien Earthquake with Seismic Methods, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5684, https://doi.org/10.5194/egusphere-egu25-5684, 2025.

Rockfalls pose significant risks, with the potential to cause severe infrastructural damage and fatalities. Among the primary weathering agents - freezing, rainfall, and thermal variations - rainfall's impact on rock weathering remains poorly understood. The mechanical properties - damage and rigidity - are crucial determinants of long-term rock stability (2). This study investigates the effects of rainfall on the sonic velocities and apparent rigidity of a natural rock column.

Ultrasonic testing, a widely used method in structural health monitoring, was employed in situ on a 50-meter-high south-facing limestone cliff overlying the Chauvet Cave in the Ardèche Plateau, SE France. This cliff experiences a range of climatic solicitations, including solar illumination, temperature fluctuations, and rainfall events. Sonic velocity changes, obtained during repeated ultrasonic testing, are indicative of internal stress variations within the rock, driven by environmental factors (thermal-acousto-elasticity, (1)).

We combined ultrasonic testing with resonance frequency measurements to evaluate stress changes at both centimeter and decameter scales of a limestone cliff. While sonic velocities provide insights into local rigidity, resonance frequency measurements reflect changes in the apparent rigidity and fracture dynamics of the rock mass as a whole. Summer rain events caused a drop in resonance frequency, likely due to rock mass contraction and fracture adjustments, while sonic velocity responses varied depending on rainfall intensity. These results suggest an interplay between rainfall and rock properties, potentially involving pore space filling and increased local rigidity from micro-crack closure. This study underscores the value of sonic velocity measurements as a proxy for assessing rock damage and rigidity, emphasizing the need for further quantification to better understand damage evolution and rock stability.
 

1 ) Guillemot, A., Baillet, L., Larose, E., & Bottelin, P. (2022). Changes in resonance frequency of rock columns due to thermoelastic effects on a daily scale: observations, modelling and insights to improve monitoring systems. Geophysical Journal International, 231(2), 894-906.

2 ) Guillemot, A., Audin, L., Larose, É., Baillet, L., Guéguen, P., Jaillet, S., & Delannoy, J. J. (2024). A comprehensive seismic monitoring of the pillar threatening the world cultural heritage site Chauvet-Pont d'Arc cave, toward rock damage assessment. Earth and Space Science, 11(4), e2023EA003329.

How to cite: Starke, J., Rousseau, R., Baillet, L., Guillemot, A., and Larose, E.: Monitoring Rain-Induced Stress Changes in a Limestone Cliff Using Ultrasonic Testing and Resonance Frequency, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5793, https://doi.org/10.5194/egusphere-egu25-5793, 2025.

Ambient seismic noise is a highly useful signal to monitor various Earth structures and processes over time. Through its excitation at the Earth’s surface by the oceans, wind and other sources, it also provides an observational basis to study the interaction between the solid Earth and its oceans and atmosphere.

While ambient noise has been used extensively for monitoring crust and soil with coda wave passive image interferometry, it remains challenging to localize and quantitatively model the observed changes. Ballistic waves retrieved by ambient noise cross-correlation, which would provide a more straightforward means to interpret observed changes, are only considered an acceptable observable for monitoring under specific circumstances due to the high spatio-temporal variability of ambient noise sources which may bias the measurements.

With the motivation to understand such biases better, we investigate the time-dependent behaviour of attenuation and phase velocity on a regional-scale, 20-year cross-correlation dataset from Switzerland, including stations in the Jura, the Molasse basin and the Alps. Seasonal variations in the composition of the ambient seismic noise field due to the generation of microseismic noise by the ocean have been previously observed. Here, we observe seasonal phase velocity and surface wave attenuation changes, which we further compare to conventional dv/v measurements and time-dependent ambient noise coda-Q measurements. To investigate these changes more quantitatively, we model ambient noise correlations numerically using pre-computed Green’s function libraries for a 3-D Earth model from SPECFEM3D_globe and oceanographically constrained secondary microseism source proxy maps. With these models we aim to determine whether the observed seasonal variations can be explained by ocean microseism source effects.

With this work, we intend to contribute to the quantitative understanding and usage of ambient noise correlations, in particular for the secondary microseism, and ultimately to detailed and interpretable time-dependent monitoring of the crust.

How to cite: Ermert, L., Boschi, L., and Obermann, A.: Zooming out: Seasonal changes shown by the background seismic wavefield in the Swiss Alps and Molasse basin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6046, https://doi.org/10.5194/egusphere-egu25-6046, 2025.

Landslides pose a significant threat to settlements, infrastructure and communities globally. In order to mitigate the potential impact and damages caused by these phenomena, various approaches and methodologies have been developed and implemented. Among these, the continuous monitoring of slope instabilities is crucial for understanding landslide dynamics and gaining information in predisposing and triggering factors. In this context, the use of passive seismic sensors has emerged as a powerful tool for monitoring, as they can detect subtle transient slope mechanical and hydrological changes as well as unpredictable episodes of signal emission associated with slope deformation processes. By continuously recording such microseismic activity, seismometers can provide data on landslide movements, offering valuable insights into the state of activity and allowing a better understanding of the relationships between the driving mechanisms.

This study provides a preliminary attempt on the investigation of slow-moving processes occurring in the region of Lower Austria, which is known to be highly prone to landslides due to its complex geological characteristics. The lithological transition between the Flysch and Klippen Unit formations consists predominantly of mechanically weak components, such as intercalated limestones and marlstones to claystone and deeply weathered materials. Combined with hydrological factors, changes in land use, and anthropogenic influences, these predisposing conditions contribute to the region's susceptibility to slope instability.

In this work, we present the results from an ongoing monitoring conducted across three well established landslide observatories in this region, which have been co-instrumented with a total of 26 geophones to monitor landslide activity. The deployed compact seismic stations consist of geophones, installed at 25 cm depth in dug pits, and a DataCube data logger recording ground velocity values at 200 Hz sampling frequency. This setup is powered by a 55Ah 9V battery and periodically visited to extract data and check the station status. Here, we evaluate and discuss the seismic expression of external drivers, co-registered slope deformation and spatio-temporal patterns of slope activity. In addition, taking advantage of the sensors included in the monitoring network installed in each site (e.g. inclinometers, piezometers), we examine the possibility of analysing the relationship with possible drivers and reactions on nested temporal scales. The findings of this work contribute to advancing the application of passive seismic monitoring technologies in landslide research, particularly in the context of slow-moving landslides.

How to cite: Marr, P., Dietze, M., Carraro, E., Kanta, R., and Glade, T.: Exploring the potential of seismic sensors in monitoring slow moving landslides in Lower Austria, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6236, https://doi.org/10.5194/egusphere-egu25-6236, 2025.

The hamlet of La Bérarde, a touristic hotspot in the French Alps for hiking and mountaineering and an iconic site in the history of alpinism, was severely impacted by the catastrophic flooding of the Etançons torrent during the night of June 20–21, 2024. The event resulted in the evacuation of 114 people, affected 66 buildings, and resulted in the complete destruction of 16 structures. The flood, characterised afterwards with a centennial recurrence interval, was caused by a combination of intense precipitation over the 2 days, significant snowmelt, and the sudden drainage of the supraglacial lake of the Bonne Pierre glacier.

Field assessments revealed that up to 300,000 m³ of sediments were transported downstream by the torrent, explaining the landscape transformation that occurred in the hamlet. Due to the evacuation of the village during the middle of the night and to the destruction of the river gauge downstream during the event,reconstructing the sequence of events involving the torrent and the associated debris flows proved challenging.

The three closest seismic stations to La Bérarde (located 15-20 km away) were used in this study to better refine the timeline of the flood. Tools such as seismic signal polarisation and spectrograms helped us to constrain the hours of the night where we observed an increase in the recorded seismic energy and a shift in the polarisation toward the hamlet. These findings align with eyewitness accounts and measurements of the Véneon River flow prior to the destruction of the river gauge by the flood.

Eventually, we installed a seismic station shortly after the flood near the front of the Bonne Pierre glacier and at the cross section of the Bonne Pierre river and the Etançons torrent to have a better idea of the sediment’s availability in case of futur glacial lake drainage. This revealed that a large amount of sediment is available and could potentially be carried by the torrent in case of another rapid drainage of the glacier.

This work was funded by the European Research Council (ERC) under grant No. 101142154 - Crack The Rock project.

How to cite: Bontemps, N., Larose, E., Chmiel, M., and Blanc, A.:  The June 2024 Flooding of La Bérarde: Insights from Seismic Data and Field Observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6557, https://doi.org/10.5194/egusphere-egu25-6557, 2025.

The Åknes rockslide is located on the slope of a steeply dipping fjord in Norway in the proximity of urban areas, posing a significant hazard due to its potential to trigger a massive tsunami. This study utilizes data from eight vertically aligned borehole geophones and one broadband seismometer on the surface, collected over a period of approximately 22 months. Previous research has demonstrated that passive seismic monitoring, specifically tracking changes in seismic velocities, can provide precursory indicators of landslide failure. This study aims to assess the potential of this method for monitoring and identifying seasonal patterns in the subsurface properties of the slope. To achieve this, we perform seismic interferometry on various frequency bands to calculate relative seismic velocity changes near the borehole and broadband station.

By integrating meteorological data from the study area, we can relate these velocity variations to environmental factors. Our analysis indicates that measurements from borehole sensors demonstrate a positive correlation between temperature and seismic velocity changes during snow-covered months, and a negative correlation during the summer, highlighting the sensitivity of seismic waves to seasonal changes and therefore different environmental regimes. Additionally, results from the broadband sensor reveal a clear decrease in seismic velocities during the melting period, and an increase in seismic velocities with increased precipitation and the reemergence of snow cover, suggesting the seismic velocities being influenced by changes in the water content. These findings advance our understanding of the relationship between calculated relative velocity changes and their connection to complex environmental interactions. This is essential for incorporating seismic velocity monitoring as a tool for assessing the stability of the Åknes slope.

How to cite: Bogner, L., Bruland, C., Langet, N., Oye, V., Hadziioannou, C., and Kiel, A.: Seismic Investigation of the Åknes Rockslide: Using Ambient Seismic Noise to Identify Possible Rockslide Movement, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7093, https://doi.org/10.5194/egusphere-egu25-7093, 2025.

Crevassing plays an important role for the stability of glaciers and ice shelves. While dry crevasses are limited in their depth of propagation by the surrounding stress field, crevasses filled with water can become unstable and propagate far deeper, providing a route for meltwater to reach the glacier bed. Hydrofracture-driven crevassing therefore has the potential to destabilise glaciers and has also been shown to cause rapid ice shelf disintegration. However, the physical mechanisms associated with hydrofracture are seldom observed. Icequakes generated by crevasse fracture provide an ideal tool to directly interrogate the process. Here, we present crevasse-driven icequakes observed using a dense 2D grid Distributed Acoustic Sensing (DAS) deployment of fibre at Gornergletscher, Switzerland. This dataset was collected during a time of high meltwater production, providing an ideal opportunity to study the fundamental physical mechanisms associated with hydrofracture failure.

We detect and locate 951 icequakes.  We then use new full-waveform inversion methods to refine event depths and obtain focal mechanisms. Furthermore, we quantify fracture mode and volumetric opening extent. We find that events typically exhibit tensile crack opening, consistent with expected crevasse fracture mechanisms. As well as direct P-wave and surface-wave energy, the waveforms contain strong coda. We attempt to isolate the spatial origin of this coda, to decipher if it is associated with either: fluid resonance at the crevasse fracture site, or wavefield scattering off other crevasses within the wider crevasse field. While we cannot definitively confirm that individual crevasse failure is caused by hydrofracture, the dense sampling provided by fibreoptic sensing allows us to interrogate the fracture mechanisms in detail. These results therefore help us understand what controls crevasse fracture propagation. Our results also highlight the application of a new generation of tools for interrogating seismic sources using fibreoptic sensing techniques in other settings.

How to cite: Hudson, T., Noe, S., Walter, F., Lipovsky, B., Kendall, J.-M., and Fichtner, A.: Interrogating crevasse icequake source physics at an alpine glacier using Distributed Acoustic Sensing, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8249, https://doi.org/10.5194/egusphere-egu25-8249, 2025.

This pilot study evaluates the feasibility of recording low-frequency elephant rumbles at the Opel-Zoo near Frankfurt am Main, Germany, using non-invasive co-located seismic and infrasound sensors. Wave-based communication of African elephants (Loxodonta Africana) is well-documented, but its study in anthropogenic zoo environments - particularly with respect to seismic signals - remains limited compared to natural habitats. Over a period of several weeks, we recorded thousands of rumbles that reveal significant temporal variability. Rumble activity exhibits a diurnal correlation with visitor numbers, while many rumbles occur in rapid sequences, suggesting interaction and potential communication among the five elephants housed in the zoo. Additionally, most rumbles are accompanied by ground vibrations, resulting from locomotion or trampling, which are not detectable through sound-only measurements. This underscores the advantages of integrating seismic and acoustic data, revealing that rumbles rarely occur as isolated events. Moreover, this study identifies potential external factors that may trigger increased rumble activity. The collected dataset provides promising insights into temporal elephant activity, helping to deepen our understanding of their behaviour and welfare in zoo environments that are highly influenced by anthropogenic conditions.

How to cite: Limberger, F., Rümpker, G., Spengler, T., and Becker, M.: Monitoring Elephant Activity Patterns in a Zoo Using Co-located Seismic and Infrasound Sensors: A Pilot Study, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8895, https://doi.org/10.5194/egusphere-egu25-8895, 2025.

Alpine glaciers have been retreating at increasing rates in recent decades due to climate warming. As a consequence, large amounts of suspended and bedload flux are exported from subglacial channels to proglacial environments, such as proglacial forefields. To date, our understanding of subglacial sediment export by subglacial streams has been predominantly shaped by suspended sediment dynamics recorded in front of shrinking glaciers, primarily due to difficulties in measuring bedload transport. Bedload transport is typically monitored far downstream from glacier termini at permanent monitoring stations (e.g. water intakes), leaving significant uncertainties regarding the absolute quantities and temporal patterns of transport in both glacial and proglacial environments, as well as its relative importance compared to suspended sediment in the context of proglacial morphodynamic filtering. Recent advancements in environmental seismology have addressed this knowledge gap. Given this, the aim of this project was to develop a novel technique for calibrating the Fluvial Model Inversion (FMI) model of Dietze et al. (2019) to quantify, for the first time, the total subglacial bedload export from an Alpine glacier and to investigate the physical mechanisms driving it.

This work focuses on a large Alpine glacier, the Glacier d’Otemma, located in the Southwestern Swiss Alps (Canton Valais). Continuous seismic data were collected in close proximity to the glacier terminus using a DATA-CUBE type 2 datalogger connected to a three-component PE-6/B geophone, over two entire melt seasons (June to September 2020 and 2021) experiencing different climatic conditions: the first year was warm and relatively dry, while the second was cold and relatively wet.

The seismic ground parameter values of the FMI model used to invert the raw seismic data into bedload transport were determined by adopting a Monte Carlo simulation based on a Generalized Likelihood Uncertainty Estimation (GLUE) approach. This involved iteratively running thousands of inversions within predefined ranges of possible ground seismic parameter values. The methodology was validated by comparing parameter values and model outputs to those obtained using a more conventional active seismic survey.

Results indicate that the developed methodology for calibrating the inversion model is promising and comparable to those derived from the more demanding active seismic survey technique. Scientifically, findings reveal a strong agreement between subglacial bedload export rates and the snowline altitude during the melt season. Extremely warm summers are associated with the exhaustion of subglacial bedload sources as the progressive rise of the snowline altitude fully exposes the glacier's bare ice, while cooler summers show the opposite pattern. This highlights the existence of a link between atmospheric temperature, subglacial drainage network extension, and bedload output rates. These results are crucial for advancing our understanding of the relationship between subglacial sediment export and meteorological conditions in a warming climate.

How to cite: Mancini, D., Dietze, M., Jenkin, M., Müller, T., Miesen, F., Roncoroni, M., and Lane, S. N.: Subglacial bedload export quantification and subglacial drainage network evolution inferred using environmental seismology techniques, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9517, https://doi.org/10.5194/egusphere-egu25-9517, 2025.

The retreat of Greenland’s glaciers is accelerating due to climate change, driven not only by rising temperatures but also by processes such as iceberg calving. These events contribute significantly to the Greenland Ice Sheet mass loss, a critical factor in global sea level rise. Identifying as many iceberg calving events as possible is essential for reducing the uncertainty in mass loss estimates, ultimately helping to improve our understanding of their cumulative impact on sea level rise and climate change.

We use seismic data to detect signals generated by time-varying forces during iceberg calving on marine-terminating glacier termini, known as glacial earthquakes. By applying a detection algorithm based on the Short-Time Average over Long-Time Average (STA/LTA) method, combined with a supervised machine learning approach (Random Forest), we successfully differentiate glacial earthquakes from tectonic earthquakes. Despite limited recordings per event, we can locate them using a non-linear location methodology (NonLinLoc).

Applying this methodology to continuous seismic data from 2013 to 2024, we identify more than 4500 previously undocumented glacial earthquakes along Greenland's coastline. While the yearly and monthly event counts are strongly influenced by the availability of seismic stations, seasonal variations in iceberg calving activity are clearly observed. This trend is further supported by an observed increase in detected events over time when focusing on a continuously available subset of stations. In addition, we will present the spatio-temporal evolution of detected events, providing further insights into the dynamics of iceberg calving activity.

These findings lay the groundwork for future work, including characterizing iceberg volume and shape to enhance our understanding of Greenland’s ice mass loss dynamics.

How to cite: Wetter, S., Mangeney, A., Hibert, C., and Stutzmann, E.: Tracking Iceberg Calving Events in Greenland from 2013 to 2024 Using Seismic Data and Machine Learning, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9652, https://doi.org/10.5194/egusphere-egu25-9652, 2025.

Following an initial landslide in Taiwan, frequent post-failure events, primarily rockfalls with occasional debris flows, pose risks to the safety of road users on a road section next to the bare land slope. To address this issue, a comprehensive warning system has been developed. This system utilizes two seismometers strategically positioned at the crown and toe of the landslide. This configuration effectively captures the physical processes of rockfalls, with the elevation difference between the stations correlating to the time difference in their peak ground velocities. Eleven seismic parameters are employed for initial rockfall detection. Subsequently, a machine learning model, trained on over 100,000 spectrograms, is implemented as a secondary filter to minimize false alarms. Additionally, the system assesses rockfall risk levels by calculating nighttime rockfall activity (from 6 PM to 6 AM) to determine a daily risk level communicated through a traffic light concept. Furthermore, the system integrates local acceleration and rainfall data to address potential coseismic rockfalls and debris flows. This data is transmitted to local electronic boards on both sides of the landslide, displaying the corresponding rockfall/debris flow risk levels with red, yellow, and green lights. Overall, this multi-tiered approach facilitates immediate hazard alerts and proactive risk management. The system provides a robust and adaptable solution for real-time warnings and risk assessments related to rockfalls and debris flows, ultimately enhancing road safety and management efficiency in hazard-prone slopes.

How to cite: Chang, J.-M. and Chao, W.-A.: Development and Implementation of a Real-Time Rockfall Warning System Using Seismic signal and machine learning analysis, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10336, https://doi.org/10.5194/egusphere-egu25-10336, 2025.

Enhancing real-time detection of mass movement events is critical for improving early warning systems and reducing risks to individuals and communities. Seismic monitoring offers an effective tool for hazard detection and timely alerts. However, a significant challenge remains in successfully isolating seismic signals associated with mass movements from continuous recordings, often obscured by persistent background noise. Therefore, it is essential to develop robust and reliable algorithms for automatic detection. This study proposes utilizing fractal geometry to quantify signal patterns across various scales, distinguishing seismic signals from background noise based on fractal dimension (FD). The study analyzed seismic data from various mass movement events, including debris flows and rockfalls in the Illgraben catchment of Switzerland and a landslide event from the Askja caldera in Iceland. Two methods were employed to estimate the FD: (i) the variogram estimator and (ii) detrended fluctuation analysis. The results show that noise typically exhibits a higher FD than the seismic signals produced by mass movements. Additionally, this study established distinct FD ranges for each type of mass movement, facilitating their classification. The outcomes also show that landslide seismic landslide signals exhibit high variability, particularly with low (signal-to-noise ratio) SNR and increased distance from the source. The findings highlight the potential for this method to improve seismic event detection in real-time monitoring systems.

How to cite: Jaffar, Q., Zhou, Q., and Tang, H.: How fractal dimension changes during mass movement events in seismic signals?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11390, https://doi.org/10.5194/egusphere-egu25-11390, 2025.

In early 2023, California was struck by intense storms from a series of atmospheric rivers, inflicting extensive damage and hardship on Californians. These storms have also alleviated California's historical drought, rapidly refilling surface reservoirs; however, it remains unclear how much water California's depleted underground reservoirs have absorbed. Understanding these aspects is crucial for assessing the state's total water deficit and guiding sustainable water management.

Here we apply advanced seismic interferometry techniques to assess the natural recharge of aquifers in Greater Los Angeles from 2003 through the 2023 storms. The derived seismic hydrographs reveal that the expression of groundwater drought is distinct from that of surface-water drought: While surface-water storage nearly fully recovered in the epic wet season of 2023, less than 25% of the groundwater lost over the previous two decades was replenished. On a decadal scale, we find significant depletion with slight storm-related replenishment in aquifers below 50 m depth. Furthermore, seismic imaging across the study area shows prominent groundwater restoration in San Gabriel Valley, highlighting the role of mountain recharge for aquifer replenishment.

This study showcases the promise of seismic sensing for providing new insights into groundwater hydrology at different depths. Our findings emphasize the need to monitor deep aquifers for a more complete assessment of water resources, which is crucial for facilitating data-informed amidst extreme weather patterns.

How to cite: Mao, S., Ellsworth, W., Zheng, Y., and Beroza, G.: How Fast, How Deep, and How Much? — Seismic Sensing of Groundwater Recharge from the 2023 Atmospheric-River Storms, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12027, https://doi.org/10.5194/egusphere-egu25-12027, 2025.

The Wind Science and Engineering Test Site in Complex Terrain (WINSENT) in SW Germany is a research facility to study wind energy harvesting in mountainous regions. WINSENT consists of two 0.75 MW wind turbines (WTs) along with a massive instrumentation for scientific measurements, including four 100 m high masts with numerous meteorological sensors at different heights. In addition, there are further open-field measurement systems such as remote sensing devices and a huge amount of instrumentation for nature conservation research, e.g. a bird radar and high-speed cameras for bird monitoring. For studying the soil-structure interaction, each WT foundation has six manholes for geotechnical and geophysical instrumentation such as pressure, displacement and seismic sensors inside the foundations. In addition, there are three shallow boreholes with broadband seismic sensors at 6 m depth and temporary seismic experiments are conducted to measure the propagation properties of seismic waves. These measurements are important for the safe and economic building of WTs and the understanding of the ground motion emissions from wind turbines. The results can later be used to design countermeasures at the source side and refine the determination of protection zones for seismic monitoring stations which can be disturbed from these emissions.

We present the design of the geoscientific research at WINSENT and the first results from seismic refraction measurements for local compressional and shear wave velocity models. The 3-D motion of the WT foundation was recovered: it is composed of a major tilt motion of a few micrometers and a minor wobble-type contribution. We acknowledge financial support by the German Federal Ministry for Economic Affairs and Climate Action, project WINSENTvalid, no. 03EE2028B.

How to cite: Ritter, J., Fesseler, P., Hirsch, J., Pena Pinto, C., Gehring, S., Stutz, H., Rettenmeier, A., and Wigger, M.: Seismological and geotechnical studies at the wind energy test site WINSENT, Germany, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12608, https://doi.org/10.5194/egusphere-egu25-12608, 2025.

Slope instabilities represent a significant hazard to communities and infrastructure across various regions worldwide. Climate change and resultant increasing severe precipitation events potentially raise the risk of failing mass movements. Therefore, a fundamental understanding of slope failure processes is vital for reducing risks. Established remote-sensing and synthetic aperture radar technologies provide valuable data on the surface movement of landslides, but only provide limited information on the instability’s internal state. In contrast, seismic imaging and monitoring techniques can provide critical complementary information on the subsurface structure, physical properties, and time-dependent processes linked to the slope instability dynamics.

The ‘Cuolm da Vi’ slope instability near Sedrun (central Switzerland) represents one of the Alps’ largest active landslides, with an estimated volume of around 150 million m³ and maximum displacement rates of up to 20 cm per year. While the instability currently does not pose an imminent danger, the slope's surface displacement is under constant observation. However, little is known about the Cuolm da Vi internal structure and dynamics at depth. The primary objective of our project is to advance our understanding of the subsurface structures and processes over time, with potential implications for deepening our fundamental knowledge of toppling instabilities in general.

In the summer of 2022, we established an extensive seismic observation network at Cuolm da Vi. This seismic sensor setup included over 1’000 autonomous seismic nodes and a 6-kilometer-long trenched fibre-optic cable. The fibre-optic sensing system was designed for long-term Distributed Acoustic Sensing (DAS) and Distributed Strain Sensing (DSS) observations. This multi-sensor geophysical network provides a unique spatial and temporal resolution for studying the Cuolm da Vi instability, allowing us to observe time-dependent changes across a wide range of spatial and temporal scales. Between summer 2022 and 2024, we gathered a comprehensive data set, including long-term continuous recordings from the nodal, DAS, and DSS systems.

Using a DAS dataset continuously collected from February to July 2023, we developed a wavefield coherence-based workflow to detect and cluster over 7’000 events recorded along the fibre-optic cable. These event clusters of highly similar seismic signals were manually classified into categories such as regional earthquakes, anthropogenic noise, rockfalls, and local seismic events, based on their time- and frequency domain characteristics. The spatial and temporal distribution of several local seismic event clusters exhibits distinct patterns that correlate closely, for example, with the surface displacement measurements. We are currently analysing these clusters of local events and investigating whether spatial links to known tectonic structures can be established, and whether the observed seismic signals allow refining the hazard scenarios and associated early warning strategies.

How to cite: Kiers, T., Grimm, J., Schmelzbach, C., Amann, F., Maurer, H., Edme, P., Poli, P., and Robertsson, J.: Fibre-Optic Monitoring of Seismic Events from an Alpine Slope Instability: Insights into Spatial and Temporal Dynamics, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13382, https://doi.org/10.5194/egusphere-egu25-13382, 2025.

Changing climate, especially the increase in frequency and intensity of extreme events such as heat waves and droughts, places many forests under significant pressure. However, we lack methods to efficiently track stress responses of trees across large scales. Real-time monitoring of physiological and structural stress indicators of trees, for instance via sap flow, stomatal conductance, or photosynthetic activity are often expensive, require high maintenance, and are therefore not efficient on a larger spatio-temporal scale.

We propose to investigate whether the stress responses of trees can be approximated as a function of the seismic power generated by tree sway - referred to as the tree’s seismic fingerprint. These wind-induced sway signals are intrinsically linked to the material properties of leaves, branches, and trunks, which are influenced by changes in cell water content and corresponding turgor pressure. Seismic measurements offer scalability and low maintenance, making them viable for extensive long-term monitoring. Moreover, the data’s high temporal resolution provides detailed and characteristic sway frequency information that could be linked to tree individuals, species or traits.

Using complementary observations from ground-based seismometers and tree-attached accelerometers collected at the ECOSENSE site in the Black Forest, we successfully isolated and analysed the seismic fingerprint of tree sway through frequency analyses and signal correlations. We further integrated these sway data with direct tree traits and meteorological time series using machine learning techniques. We present the first results of this innovative approach, marking a significant step towards understanding the intricate relationship between tree motion and their immediate surrounding ecosystem.

How to cite: Umlauft, J., Mora, K., Kattenborn, T., Wirth, C., and Werner, C.: The Seismic Fingerprint of Tree Sway, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15658, https://doi.org/10.5194/egusphere-egu25-15658, 2025.

River-ice affects hydraulics and sediment transport that may in turn influence channel morphology. However, scientific understanding of sub-ice flows is limited by the difficulty of accessing the ice-covered channel bed and banks. During periods of stable ice cover, hydraulic studies usually assume that the stable ice cover is free-floating and can therefore move vertically to accommodate changes in river discharge. However, ice cover is often fixed in place, attached to the channel banks. In this case, increasing discharge is forced under the ice cover causing pressurized flows typified by higher flow velocities and sediment transport. The identification and study of pressurized flows is difficult due to the challenges of measuring flows in ice-covered rivers during high discharges; in particular since common methods of drilling holes to measure velocities will disrupt any potential pressurization.

We aim to determine if environmental seismology can be used to identify pressurized flows in rivers and to interpret the characteristics of seismic signals to inform knowledge of hydraulic processes during pressurized flow events. Thus, we set up a flume experiment to compare the hydraulic seismic signature of free-surface flow with pressurized flow under fixed ice-covered conditions. Using a 7m-long transparent 10 x 10 cm PVC tube and fixing roughness elements onto the riverbed (sand and gravel), we test three configurations varying the discharge and the distance between the bed and the bottom of the ice cover (simulated by the upper surface of the inside of the tube). The slope is 0.3 % to represent prototype low-slope subarctic river channels. Two PE6/B three-component 4.5 Hz geophones record millisecond resolution seismic data: one is installed on top of the water-filled flume, and the other on an empty 1m-long section of the same type of PVC tube placed next to the flume, to record background noise. We can pressurize the water-filled flume by increasing the discharge for a given treatment, and record discharge and video data to identify and describe pressurization events.

Comparing seismic and discharge data confirms that we can identify hydraulic signals in the seismic record. We observe a scaling relationship between discharge data and seismic power, and are investigating its coherence with existing theoretical models and its dependency on apparent bed roughness. We expect pressurized flows to appear as high-energy signals due to increased water velocity, with a decrease in background noise due to complete contact between the water and the pipe.

These results can help resolve a long-term aim of identifying the occurrence of sub-ice pressurized flows from seismic field data. Such understanding has implications for using seismic signals to calculate stage in ice-covered rivers or subglacial channels and calculating ice-related bedload transport. These techniques provide unparalleled opportunities for non-intrusive and continuous measurements of hydraulic processes under ice.

How to cite: Laporte, S., Gimbert, F., Buffet, A., Bellot, H., Polvi, L. E., and Mason, R. J.: Identifying pressurized flows under river-ice using seismology: insights from a flume experiment, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16277, https://doi.org/10.5194/egusphere-egu25-16277, 2025.

The microtremor measurements data have been carried out in 72 locations in and around Varanasi city (Uttar Pradesh), India, to understand the local site conditions and preliminary site effect of the Quaternary sediments of Varanasi in the Indo-Gangetic plain. Estimated outcomes from the horizontal to vertical spectral ratio show the predominant frequency varies from 0.34 Hz to 0.94 Hz, site amplification varies from 1.96 to 3.88, and the vulnerability index (Kg) varies from 4.82 to 39.61, and the low shear wave velocity (approximate ~ 300 m/s) down to the depth of 30 m is evident from the synthesis of the 1-D velocity model for the city, which are classified as class D soil type (NEHRP classification). The primary goal of the current study is to determine the dynamic properties of soil response during a potential earthquake in Varanasi city The obtained results will support the seismic microzonation study by identifying areas prone to liquefaction and aiding in mitigating the risks associated with near-surface site failures during seismic activity in and around Varanasi city.

How to cite: Yadav, A. K. and Sengupta, P.: Microtremor measurements and analysis for local geology condition of Varanasi city based on seismic vulnerability index (kg), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16364, https://doi.org/10.5194/egusphere-egu25-16364, 2025.

In recent years, Oman has faced increasing challenges with flash floods, driven by climate change and rapid urbanization. Climate change has intensified the water cycle, causing more frequent and severe precipitation in this arid region. Urban expansion into wadi floodplains, which historically acted as natural flood channels, has worsened the situation. Oman's flood preparedness is critically hindered by the lack of effective early warning systems. While sensor networks could monitor rainfall and wadi flow to provide flood alerts and water management data, their implementation is limited by the country's vast territory, complex terrain, and high infrastructure costs.

The existing wadi monitoring infrastructure in Oman relies on two primary types of measurement devices: pressure gauges and radar sensors. However, each technology presents distinct operational challenges in the dynamic wadi environment. Pressure gauges, which must be installed directly within the wadi bed to measure water levels, are vulnerable to damage or complete loss during powerful flood events. Radar gauges, while avoiding direct water contact, face different limitations. These devices are typically mounted on structures along the wadi banks to measure water levels from above. However, this positioning becomes problematic due to the naturally shifting nature of wadi channels, which can migrate significantly over time through erosion and sediment deposition.

Image-based monitoring systems offer a promising solution to the challenges of wadi measurement. Cameras can be safely installed outside the channel while maintaining visibility across the entire river cross-section. Different studies have shown that cameras can accurately measure water levels, even with low-cost equipment. Moreover, these systems can measure flow velocities by analysing short video sequences, enabling discharge estimation. However, image-based methods have a significant limitation: they perform poorly in challenging lighting conditions, e.g. at night, during heavy rain or dust events.

Recently, seismic observations were utilized to infer river level and bedload flux, using low cost sensors (e.g. Raspberry Shake) installed at safe distance to the hazardous flood corridor. These studies employed physical models, which predict the seismic frequency spectra created by bedload transport and turbulent flow. Those models rely on a large number of parameters to be set, including water level. Therefore, Monte Carlo approaches are used to randomly sample parameters for synthetic spectra calculation to be compared against the empirical one, ultimately leading to the water level.

The integration of cameras and seismic sensors can allow for a robust and synergetic measurement system. Optical measurements of water level and surface velocities can effectively constrain the parameters used in seismic signal analysis, significantly improving water level estimation accuracy when image-based methods are not available, particulary during night time operations. With the increasing availability of low-cost seismometers, we have developed and implemented a combined low-cost seismo-optical monitoring system. To evaluate this approach, the setup was installed at two reaches of Wadi Al-Hawasinah in Oman. Our study examines initial results from flow events of varying magnitudes and assesses the practical applicability of this integrated monitoring solution.

How to cite: Krüger, R., Dietze, M., Grundmann, J., Al-Rawas, G., and Eltner, A.: Low-cost instrumentation for monitoring wadi discharge: A Raspberry Shake and time-lapse camera system, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16371, https://doi.org/10.5194/egusphere-egu25-16371, 2025.

Subglacial processes are difficult to monitor due to their inaccessibility with conventional hydrological probes. We know relatively little about when and at what rate the products of subglacial erosion are evacuated, especially for coarse sediment (bedload). Environmental seismology is contributing to close this knowledge gap, providing some of the first, seasonal-scale datasets on bedload evacuation by subglacial streams. The advantage of seismic monitoring of subglacial sediment transport is that it does not need to be installed directly into the water.

The location of a static subglacial channel can be found using techniques such as GPR surveys, but rapid changes in the subglacial channel system require continuous data sets on channel location. Monitoring seismic amplitudes and applying beamforming methods to seismic array records, one can locate noise sources and thus identify variations in activity and location of subglacial streams and bedload transport. This may be done using arrays of seismic nodes and/or distributed acoustic sensing (DAS) along an optical fiber. To identify the best use of such methods for monitoring the subglacial stream, the present study compares conventional seismic sensors and fiber optic cables for beamforming source location.

The field site of this study is Glacier d’Otemma in Valais, Switzerland. Given two data sets of seismic nodes and DAS, as well as ancillary observations, we can identify the location of the subglacial river and track changes in its discharge and bedload transport rate. These findings mainly relate to variations in seismic noise throughout the diurnal cycle of glacier melt. Depending on frequency band and daytime, the location of the most intense seismic noise, averaged over two hours, varies. These variations relate to processes such as surface melt, which stops during night, and subglacial flow, which continues but is less intense. Seismology proves to be a temporally and spacially rich tool to monitor this constantly changing activity of glaciers.

How to cite: Wolf, E., Stutzmann, E., Metaxian, J.-P., Nanni, U., Miesen, F., Ballu, A., Walter, F., Mangeney, A., Arbeu, R., Schimmel, M., Dietze, M., and Lane, S.: Comprehensive monitoring of the subglacial stream of Glacier d'Otemma using seismic nodes and distributed acoustic sensing data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16515, https://doi.org/10.5194/egusphere-egu25-16515, 2025.

Understanding bedload transport is crucial for predicting sediment flux and managing fluvial systems. Previous studies, such as those by Burtin et al., (2016); Gimbert et al., (2016), and Piantini et al., (2022), have explored fluvial dynamics using dense arrays with up to 80 sensors in alpine regions like the Himalayas and Alps. However, these approaches are less adaptable to a wider variety of ecosystems. Our study addresses this gap by developing a seismic array geometry tailored to diverse fluvial environments, optimizing signal location while maintaining scalability and adaptability.

We introduce a framework for optimizing array geometry and integrating beamforming as well as directivity analyses to enhance accuracy of signal detection. Results indicate that strategic seismic sensor placement significantly improves location precision and minimizes ambiguities caused by overlapping signals. These findings establish a robust methodology for continuous, non-invasive monitoring of fluvial bedload transport, applicable across morphologically diverse river systems.

Preliminary results from the Arroyo de los Pinos, New Mexico—a semi-arid, flash-flood-prone environment— are promising with interactive positive components. An optimized array comprising 17 seismic nodes, covering frequencies from 1 Hz to 100 Hz, was deployed and optimized for signal processing with numerical modelling. Future efforts will extend this framework to other ecosystems, refining predictive capabilities and advancing sediment management strategies.

Reference

• Burtin, Arnaud, et al. "Spectral analysis of seismic noise induced by rivers: A new tool to monitor spatiotemporal changes in stream hydrodynamics." Journal of Geophysical Research: Solid EarthB5 (2008).
• Burtin, Arnaud, Niels Hovius, and Jens M. Turowski. "Seismic monitoring of torrential and fluvial processes." Earth Surface Dynamics2 (2016): 285-307.
• Gimbert, Florent. "Using array seismology to quantify river physics." AGU Fall Meeting Abstracts. Vol. 2016. 2016.
• Piantini, Marco, et al. "Using a dense seismic array to study fluvial processes in a braided river reach under flood conditions." LHB1 (2022): 2053314.

How to cite: Padmadas, A., Laronne, J., Walter, F., Bilek, S., and Turowski, J.: Precision in Seismic Detection of Bedload Transport: Visualizing Array Geometry for Optimal Source Localization, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16545, https://doi.org/10.5194/egusphere-egu25-16545, 2025.

Glacier grounding zones, where ice transitions from resting on land to floating on ocean, are critical to understanding ice sheet dynamics and stability. Despite their importance, these regions are challenging to study directly due to their inaccessibility and the inherent risks of fieldwork. To address this, we conducted seismic investigations at Eastwind Glacier, Antarctica, an accessible grounding zone near McMurdo Station and Scott Base, as part of the EGGS on TOAST project. Our fieldwork included deploying 330 three-component seismic nodes across the grounding zone during the austral summer of 2022/23, capturing continuous data for nine days on all nodes, with extended recordings of 19 days on 150 nodes. Active-source seismic data were acquired using hammer-and-plate shots, both densely spaced along the array's centerline and at individual node locations. In the following field season (2023/24), we supplemented these observations with distributed acoustic sensing (DAS) using a fiber optic cable positioned downstream of the grounding line for cross- and along-flow imaging. Initial analyses of the seismic data reveal key features, such as the flotation point of ice and ice and firn thickness variations. Additionally, passive seismic methods provide insights into icequake activity and ambient noise characteristics. This comprehensive dataset offers a new perspective on grounding zone processes and serves as a valuable resource for testing innovative cryo-seismological techniques. 

How to cite: Young, T. J., Pearce, E., Agnew, R., Karplus, M., Ranganathan, M., Hoffman, A., Hunt, M., Pretorius, A., Shanly, S., Beres, M., Pradhan, K., Seldon, Y., Booth, A., and Clark, R.: Active and passive seismic surveys over the grounding zone of Eastwind Glacier, Antarctica, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17047, https://doi.org/10.5194/egusphere-egu25-17047, 2025.

How do we pinpoint fleeting geomorphic surface events in the planet's remotest corners, where no witness observes and classical methods falter? Processes like landslides, debris flows, avalanches, and rockfalls not only sculpt the Earth's dynamic landscape but also pose significant hazards in remote and populated areas alike. As environmental changes intensify, closing the gap of elusive detection holds profound implications for disaster response, hazard prediction, and geomorphic theory advancement. The difficulty lies in the concealed, stochastic nature of these processes and the challenges of direct observation. Continuous high-resolution seismic sensing offers unique potential to detect and locate geomorphic sources that evade other tools. However, surface processes generate chaotic, site-specific waveforms with rapid, nonlinear energy release, often in noisy, inaccessible settings. Existing, rigid location techniques are ill-equipped for this challenge, failing to match known details of historic geomorphic sources. We introduce a hybrid, nature-inspired seismic event location approach that fuses physical and biological principles to overcome longstanding obstacles in monitoring geomorphic processes.

Our method synergizes deterministic and heuristic elements into a robust, self-adaptive framework. The source location is approximated first by a hybrid of grid search, modified gradient descent, and full waveform inversion. A bio-inspired procedure then iteratively refines this output to near-optimal solutions. Our method autonomously picks arrival times through a multi-layered structure, leveraging dynamic time warping, Bayesian inference, and SNR optimization. Composite misfit metrics from synthetic and observed waveforms guide location estimation in a dynamic solution landscape. This search space self-adjusts to instrument network layout and landscape complexity using Voronoi tessellation, convex hulls, and velocity-refined grids.

The cornerstone of our approach is a biomimicry component, inspired by the adaptive, collaborative behaviors of diverse animal species. We leverage over ten animal behaviors mathematically encoded as optimization agents. Each species epitomizes niche strategies based on their specific strengths. For instance, elephants’ memory and herding guide global searches, fireflies’ light-attraction principles refine locally, and whales’ spiral foraging navigates complex search spaces. Guided by evolutionary mechanisms, predator-prey dynamics, and interagent communication, collective intelligence and a recursive memory are built, and global exploration is seamlessly integrated with local information, balancing far-field searches with near-field precision.

As a benchmark we will use a seismic dataset of 290 geomorphic events, spanning diverse types, scales, and complexities, worldwide. Preliminary results show a 47–200% reduction in location misfit compared to brute-force methods, which mislocate events by 11–20 km. Biomimicry achieves relocation precision of 2.6 km, reducing misfits by up to five orders of magnitude. Improvements are achieved within 150 iterations across varying noise levels, with location standard deviations as low as 1–2 km. Additionally, the method isolates subsurface anomalies, estimates source depth, provides a pathway to track process propagation, and can eventually integrate into real-time early warning systems.

By bridging geomorphology, biology, and seismology, our work elevates the capacity to detect surface processes with accuracy, adaptability, and scalability. Intelligent, resilient, and inspired by nature itself, it lays a foundation for applications ranging from hazard monitoring to planetary exploration.

How to cite: Ursica, S. and Hovius, N.: Nature’s intelligence: Hybrid bio-inspired method yields more accurate seismic locations of geomorphic events, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17862, https://doi.org/10.5194/egusphere-egu25-17862, 2025.

The water cycle impacts geophysical signals, influencing our ability to monitor subsurface hydrology. At the Membach geophysical station in Belgium, we integrate gravity and ambient seismic noise data to study hydrological variations and develop a numerical hydrological model at a local scale. Our findings reveal that gravity observations at Membach station exhibit gradual changes, reaching a peak at ± 2-day after rainfall, reflecting subsurface water redistribution and storage processes. Concurrently, increased soil saturation corresponds with a decrease in HVSR (Horizontal-to-Vertical Spectral Ratio), indicating reduced stiffness and changes in seismic wave propagation. Furthermore, relative velocity changes (dv/v) show frequency-dependent time delays, with deeper layers exhibiting slower responses compared to shallower regions. These results highlight the dynamic relationship between rainfall, soil saturation, and geophysical responses, providing new insights into critical zone processes. By combining gravimetry and ambient seismic noise, we address challenges in studying deep and complex subsurface zones, where traditional hydrological methods often fall short. This approach not only enhances our understanding of subsurface hydrology but also improves water resource management and critical zone studies. The integration of geophysical methods offers a comprehensive framework for monitoring hydrological dynamics, advancing our ability to interpret geophysical signals influenced by the water cycle and providing a valuable tool for managing environmental and climatic impacts on subsurface water storage.

How to cite: Saraswati, A., Lecocq, T., and Vanclooster, M.: Investigating Soil Saturation Changes through Geophysical Data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18249, https://doi.org/10.5194/egusphere-egu25-18249, 2025.

An important consequence of the rapid retreat of Alpine glaciers associated with global warming is the increasing extent of proglacial areas. These environments are dominated by a heterogeneous and dynamic fluvial system, whose evolution mostly depends on the interplay between the varying water discharge and coarse sediment supply coming from the glacier terminus. Although understanding the impact of glacier retreat on bedload yield is essential for the preservation of high-mountain regions, long-lasting investigations on the processes occurring in proglacial areas are lacking. In this context, seismic sensors recording river-induced ground vibrations have been shown to constitute a valid monitoring technique (Mancini et al., 2023; Corte et al., 2024).

Here, we present the results of monitoring campaigns carried out in the proglacial area of the Rutor Glacier (Aosta Valley, Italy) during the ablation seasons of the last three years. Ground vibrations have been monitored using a network of three geophones installed next to a stable reach of the main proglacial torrent  ∼150 m downstream of the glacier mouth. Direct measurements of bedload transport have been made in 2022 and 2023 by deploying portable bedload traps at the glacier mouth. In addition to meteorological data gathered at a weather station, water discharge has been estimated by means of a downstream gauge station. We have found that a varying and non-trivial relationship exists between the direct bedload measurements and the recorded seismic signals, indicating a potential strong buffering of sediment export exerted by the proglacial area. Moreover, for all the three monitoring campaigns but starting at different moments of the ablation season, we have observed quasi-periodic peaks of seismic power occurring at a sub-hourly scale during the afternoon. We advance that they could be related to water discharge fluctuations resulting from the dynamics of the subglacial drainage system. These observations show the effectiveness of using seismic methods to shed some light on the complex feedback mechanisms existing between glacier dynamics and the natural processes of proglacial areas.

References

Mancini, D., Dietze, M., Müller, T., Jenkin, M., Miesen, F., Roncoroni, M., et al. (2023). Filtering of the signal of sediment export from a glacier by its proglacial forefield. Geophysical Research Letters, 50, e2023GL106082. https://doi.org/10.1029/2023GL106082

Corte, E., Ajmar, A., Camporeale, C., Cina, A., Coviello, V., Giulio Tonolo, F., Godio, A., Macelloni, M. M., Tamea, S., and Vergnano, A. (2024): Multitemporal characterization of a proglacial system: a multidisciplinary approach, Earth Syst. Sci. Data, 16, 3283–3306, https://doi.org/10.5194/essd-16-3283-2024

How to cite: Piantini, M., Corte, E., Camporeale, C., Tamea, S., Crema, S., and Comiti, F.: Seismic monitoring of the Rutor proglacial stream: exploring the impact of glacier dynamics on water flow and bedload transport processes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19268, https://doi.org/10.5194/egusphere-egu25-19268, 2025.

The Mansfelder Mulde (German for trough) around Lutherstadt Eisleben is considered as an active subsidence area. Deep-seated subrosion is the potential reason for large- and small-scale earth surface deformation. The appearance of sinkholes as potentially hazardous surface expression of karst has led to increasing interest in the area. Specifically, in the study area Neckendorf in the southwest of the Mansfelder Mulde, two major sinkholes occurred in the early 2000s, affecting a federal road and an allotment garden site. At the end of 2021, surface cracks formed again along a main road just 800 meters away from the previous sinkholes. This process is attributed to ongoing subsidence in the adjacent field. The continuous ground movement, coupled with significant surface cracking along an additional road causing severe traffic problems, necessitated the complete closure of both roads in December 2022.

The subsidence area has been investigated by the State Office for Geology and Mining (LAGB) Saxony-Anhalt since 2022 and is since March 2024 a research topic of the UL. During first field measurements, the edge areas of the subsidence were surveyed using Electrical Resistivity Tomography (ERT). In addition, three seismic stations were recently (November 2024) installed to investigate the ground movements in the context of the large-scale subsidence. Currently, no results from the seismic data are available. Once the field data has been retrieved, it will be analyzed in conjunction with the existing ERT data to discuss the subsidence event. With the help of long-distance (deep) ERT we aim to decipher the hydrogeologic conditions of the Anhydrite and Gypsum Zechstein layers, at the supposed base of the subrosion. One objective was to detect, cracks and loosening zones also in the overlying lower Buntsandstein layers. Several profiles were created along the neighbouring fields and the affected roads. Due to different electrical material properties compared to the surrounding soil material, the suspected subrosion features appear as anomalies. ERT showed a clear difference between farmed and abandoned, non-farmed areas. Higher resistivities indicate a deformed subsoil, and with high probability an extension of the loosening zones beyond the crack formation visible on the surface. Near vertical lower-resistance structures could indicate water-saturated fracture zones in context of the main subsidence. Furthermore, the effects of a defective water pipe were possibly detected with ERT. As it is currently not possible to estimate how the subsidence will develop, the evaluation of geophysical data is significant for local hazard assessment and should, above all, provide the affected farmers with clarity about the subsoil situation of their fields and inform local stakeholders about the ongoing process.

How to cite: Silbermann, M., Khosravichenar, A., Aalijahan, M., Ginga, M., Rappsilber, I., Sänger, N., Gauert, C., Seidemann, J., Umlauft, J., and Al-Halbouni, D.: Geoelectrical and seismic investigation of a subsidence geohazard zone in Neckendorf, Saxony-Anhalt, Germany , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20756, https://doi.org/10.5194/egusphere-egu25-20756, 2025.

Assessing and quantifying bedload dynamics and sediment transport rates in rivers is critical for evaluating the landscape evolution, which in turn controls channel morphology and catchment erosion. In the last decades, seismic observations emerged as one of the most promising tools for monitoring river dynamics. In particular, recorded seismic energy has been shown to correlate with river discharge and with the amount of transported sediments. However, uncertainties persist in quantifying bedload transport using recorded seismic signals. This lack is particularly relevant for small mountain streams, where sediment mobilisation begins, that have been to date poorly studied.

In this study we present the first outcomes of two years of continuous seismic monitoring of the Re della Pietra, a small stream in Tuscan Appennines. Specifically, we analyse data collected by two triaxial seismometers placed in two different channel sections, deployed on the riverbank, ~3 meters from the stream. Root-mean-square amplitude analysis (RMSA) is used for computing the envelopes on recorded data as well as analysis on frequency domain is performed for investigating the spectral content of the signal. Over the two years of observations many flood events were recorded, ranging from small and short (few hours) events to massive and long (days) ones related to exceptional storms. Recorded seismic data shows peculiar waveform and spectral footprints. To investigate how flow dynamics affect seismic radiation, collected seismic data are compared with flow depth data and video images acquired by during the events. Preliminary results highlight important constraints on the mobilizations of the solid particles within small creeks thus suggesting how seismic sensors can be successfully used for monitoring the bedload transport.

This study is being carried out within the interdisciplinary project TRANSFORM (“A new interdisciplinary approach to advance understanding of sediment and large wood TRANSport in FORested Mountain catchments”- https://florenceuniversity.wixsite.com/transform).

How to cite: Marchetti, E., Belli, G., Gheri, D., Innocenti, L., Murgia, I., Chirici, D., Verdone, M., Nicoletti, S., Solari, L., Morandi, O., and Penna, D.: Seismic analysis of bedload transport in a small mountain creek, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21164, https://doi.org/10.5194/egusphere-egu25-21164, 2025.

Around 50 years ago, David Sugden and Brian John proposed a classification scheme for landscapes formed by glacial erosion, based on the geomorphic evidence from the beds and peripheries of Quaternary ice sheets. This evidence was interpreted qualitatively using aerial photography and limited field visits. In the current era of ubiquitous, freely available, high-resolution elevation data, limited attempt has been made to update this classification using quantitative measurements of landscape form (i.e., morphometry), and no such scheme has been applied to the Northern Hemisphere regions where the scheme was originally developed. This is despite landscapes of glacial erosion containing a wealth of information relating to past ice behaviour. This study therefore aims to create a new classification method which: (1) has a robust quantitative basis allowing it to be reproducibly applied to new land surfaces, including those currently buried beneath modern ice sheets; and (2) takes advantage of the power of machine learning approaches to interpret patterns at scale and provide estimates of classification confidence. The method presented here uses intuitive morphometrics that can be calculated relatively simply from digital elevation models, including total relief, spatial density of local peaks and basins, and drainage characteristics. A random forest classifier is trained on a selection of manually classified landscapes and the resulting model is used to reclassify the exposed regions of northern North America. Classification confidence is examined using decision tree voting scores, and ‘out of bag’ error values are used to estimate variable importance. The results align broadly with the original 1970s classification scheme, but reveal more local- to regional-scale and intraclass variability than was previously accounted for. Low confidence scores allow identification of landscapes which represent a more complex interplay of different erosional styles, or a transition between classes. The classification also highlights the preservation of a range of non-glacial erosional signatures, even in areas known to have been affected by Quaternary glaciations. Overall, the work demonstrates the value of simple morphometric parameters for condensing information from large elevation datasets and provides a quantitative tool for interpreting landscapes whose glacial history is poorly constrained, such as those hidden beneath modern ice sheets, or on other planets.

How to cite: Lea, E., Paxman, G., Clubb, F., and Ross, N.: Continental-scale machine-learning classification of glacial landscapes using simple morphometric parameters, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-342, https://doi.org/10.5194/egusphere-egu25-342, 2025.

How to cite: Haunsperger, V., Robl, J., Argentin, A.-L., Hergarten, S., and Schröder, A.: Computing the state of stress in mountain massifs undergoing topographic decay , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1292, https://doi.org/10.5194/egusphere-egu25-1292, 2025.

Coastal inlets serve important navigation and environmental functions for coastal regions. Managing inlets is a complex task that requires a thorough understanding of several key factors, including sediment transport, areas of erosion and deposition, and feature migration within the inlet system. This knowledge can enhance the maintenance of navigational channels, identify sediment borrow areas for coastal engineering projects, and optimize hydrodynamic and sediment transport models. To improve coastal inlet management in the U.S., the U.S. Army Corps of Engineers (USACE) Coastal Inlets Research Program develops tools to reduce Operations and Maintenance (O&M) costs at federally maintained inlets. One such tool is the U.S. Coastal Inlets Atlas, an online database of information for U.S. inlets (Beck & Arnold, 2019). 
This research highlights emerging tools and methodologies to be included in the next generation of the U.S. Tidal Inlet Atlas for inlet geomorphic mapping and analysis that will provide USACE District engineers, scientists, and managers, as well as other public partners, with tools and data to rapidly evaluate O&M alternatives. These tools include workflows to map inlet geomorphic features more accurately and to better track and predict morphologic changes. Emerging methods that were tested in this study include relative relief mapping (Wernette et al., 2016), Geomorphon classification (Jasiewicz & Stepinski, 2013), and chronostratigraphic and conformal mapping analyses (Pearson et al., 2022). These methods make use of publicly available repeat bathymetric data including USACE National Coastal Mapping Program topobathymetric lidar and USACE hydrographic surveys. Workflows to pre-process bathymetry data and conduct the new analyses as well as results from tests cases at New Pass and Merrimack Inlets in the U.S. are presented here. Highlights of the tool and workflow development and testing include: (1) the importance of considering scale when implementing relative relief mapping and geomorphon methods; (2) the importance of choosing the inlet polar grid origin and transect locations for conformal mapping and chronostratigraphic analysis methods. Results of the test study site analyses highlight geomorphic features such as shoals, reveal sediment transport pathways, and provide estimates of shoal and ETD sediment volumes and ages of deposition. The study provides valuable data products and workflows to engineers and scientists interested in applying these approaches to additional inlets. Fully developed workflows and datasets will be included in future iterations of the U.S. Tidal Inlet Atlas for all federal inlets.

Beck, T. M., & Arnold, D. (2019). U.S. Tidal Inlets Atlas: An Update to the CIRP Inlets Database (Coastal and Hydraulics Engineering Technical Note (CHETN) IV–118). USACE, Engineer Research and Development Center.

Jasiewicz, J., & Stepinski, T. F. (2013). Geomorphons—A pattern recognition approach to classification and mapping of landforms. Geomorphology, 182, 147–156. 

Pearson, S. G., Elias, E. P. L., Van Prooijen, B. C., Van Der Vegt, H., Van Der Spek, A. J. F., & Wang, Z. B. (2022). A novel approach to mapping ebb-tidal delta morphodynamics and stratigraphy. Geomorphology, 405, 108185. 

Wernette, P. A., Houser, C., & Bishop, M. (2016). An automated approach for extracting barrier island morphology from digital elevation models. Geomorphology, 262. 

How to cite: McPherran, K., de Assis Bose, M., Shawler, J., Sylvester, C., and Smith, K.: Innovative Tools for Inlet Geomorphic Mapping: Testing Emerging Methods at New Pass Inlet, Florida and Merrimack River Inlet, Massachusetts, USA, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3282, https://doi.org/10.5194/egusphere-egu25-3282, 2025.

Quantifying riverscape topography is challenging because riverscapes comprise of both wet and dry surfaces. Over the last decade, considerable advances have been made in demonstrating the capability of mounting topo-bathymetric LiDAR sensors on crewed, occupied aircraft to quantify riverscape topography. However, only recently has miniaturisation of electronic components enabled topo-bathymetric LiDAR to be mounted on consumer-grade Unoccupied Aerial Vehicles (UAVs). Here we evaluate the capability of YellowScan Navigator topo-bathymetric LiDAR sensor, mounted on a DJI Matrice 600 UAV, to survey a 1 km long braided riverscape. This sensor uses full waveform returns, to ensure continuity between underwater points and the surrounding terrain, and has a 44° field of view. In August 2024, a point cloud was collected across a 1 km long, 200 m wide reach of the braided River Feshie, Scotland. Ground-truth data were collected across wet areas using a Sontek M9 Acoustic Doppler Current Profiler (ADCP) as an echo-sounder, and also survey-grade RTK-GNSS (Global Navigation Satellite System) in both wet and dry areas. The processed LiDAR point cloud featured over 10 million points, with a density of approximately 62 points / m². These points were compared to the ground truth data to assess the vertical accuracy of the survey. Ground-truth mean errors (and standard deviation) across dry gravel bars surveyed with RTK-GNSS were 0.06 ± 0.04 m (n=237). Mean errors along the bed of the shallow channels surveyed with RTK-GNSS were -0.04 ± 0.23 m (n=562). Additionally, mean errors for deeper channels measured with the ADCP’s echo sounder were -0.08m ± 0.23 m (n = 2673). Overall, this case study demonstrates the potential of using a new generation of topo-bathymetric LiDAR sensors that can be mounted on UAVs. This has the potential to further enhance field surveys of wet-dry environments by reducing logistical workloads and increasing efficiency of these surveys. Compared to the various techniques for correcting bathymetric data from Structure-from-Motion imagery or point clouds this direct measurement needs less processing to achieve to continuous topo-bathymetric surface.

How to cite: MacDonell, C., Williams, R., White, J., and Roberts, K.: Seamless quantification of wet and dry riverscape topography using UAV topo-bathymetric LiDAR, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4410, https://doi.org/10.5194/egusphere-egu25-4410, 2025.

As critical zones in fluvial geomorphology shaped by hydrological processes, valley floors play an essential role in material exchange and circulation between upland and groundwater bodies. Their accurate delineation is crucial for understanding river morphology, analyzing the distribution of valley floor sediments, and maintaining the riverine landscape ecosystem. However, current methods for delineating valley floors are highly artificial, region-specific and require subjective parameter selection. To address these limitations, we develop a multi-scenario adaptive framework for delineating valley floors. This framework designs several indicators for automatically detecting topographical cross-sectional and longitudinal features, providing a basis for parameter determination in valley floor extraction and achieving geomorphologically adaptive automatic extraction. The framework includes the following components: (1) The initial drainage network was extracted by setting drainage thresholds based on geomorphological texture features obtained using the gray-level co-occurrence matrix (GLCM); (2) The drainage network generated in the previous step was filtered by calculating the average river gradient and setting adaptive parameters, removing drainage networks located in steep valleys; (3) The valley floor extent was adaptively extracted by proposing terrain factors such as slope accumulation and its variation. The experimental results demonstrate that this method applies to the extraction of valley floors in various geomorphological types, exhibiting high precision. This study also explored the correlation between river valleys, geological sedimentation, and surface hydrological processes, finding a significant consistency between sediment distribution and valley floor extent. These findings provide a new perspective for research on geological mapping, and the evolutionary patterns of valley floor morphology.

How to cite: Sun, W., Chen, Y., Zhou, X., Yang, X., Ma, J., Li, S., and Tang, G.: Understanding the hydrological valley landscape: a multi-scenario adaptive framework for delineating valley floors, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5028, https://doi.org/10.5194/egusphere-egu25-5028, 2025.

The mud volcanoes in Romania are among the most well-preserved and accessible mud volcano fields in Europe. They represent important natural heritage and, at the same time, offer a unique natural laboratory for studying the interplay between tectonics and hydrocarbon fluid escape in an active geological setting. However, these mud volcanoes remain understudied. Here, we present an integrated UAV approach (LiDAR, photogrammetry, thermal imaging) to investigate relevant aspects of the Pâclele Berca, Mici, Mari, and Beciu located in Buzău Land UNESCO Global Geopark, Romania.

The Pâclele Mici mud volcano is an area of complex geology shaped by tectonic phases from the Late Cretaceous and Early Miocene periods. Situated on the Berca–Arbanasi anticline near the seismically active Vrancea zone, this site is geologically significant as it represents an interaction of methane-rich fluids with neotectonic faults and is possibly still influenced by a seismogenic area, creating a dynamic and unique environment.

In 2024, UAV-mounted LiDAR, photogrammetry, and thermal sensors were deployed to collect high-resolution spatial and thermal data over the Pâclele Mici site. The LiDAR system provided precise digital elevation models, revealing subtle patterns of surface deformation, including subsidence and uplift, that evolve with mud volcanic activity. Photogrammetry generated detailed orthomosaics, allowing for an in-depth assessment of surface morphology, textures, and fissures. Thermal imaging highlighted temperature anomalies linked to active venting and subsurface fluid movement, offering insights into the system's thermal behavior and energy flux. These datasets revealed significant surface deformation and distinct thermal anomalies concentrated around active vents when analyzed together. Subsidence and uplift patterns correlated with zones of intense fluid discharge, aligning with findings from previous deep geoelectrical surveys.

By combining spatial, morphological, and thermal datasets, this research provides a holistic view of the Buzau Land Geopark mud volcanos, enhancing our understanding of their evolution and the mechanisms driving their activity. The findings underscore the importance of remote sensing technologies in studying dynamic geological systems and contribute valuable insights into the broader implications of mud volcanism, including its role in methane emissions, landscape evolution, and geological hazards. This multidisciplinary approach sets a foundation for future studies and monitoring efforts at Pâclele Mici and globally in similar active settings.

Keywords:  Remote Sensing,  UAV Technologies, Mud Volcano

Acknowledgments: This work was done in the framework of the National Research Program, project SOL4RISC no. PN 23360301

How to cite: Nastase, I. E., Cerbu, B., Petrescu, A., Gerea, A., Mihai, A. E., and Tataru, D.: Geomorphological and Thermal Monitoring of Mud Volcano Landscape with UAV Technologies, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6529, https://doi.org/10.5194/egusphere-egu25-6529, 2025.

In the context of climate change, ice sheets are strongly influenced by the reorganization of the subglacial hydrological system and the dynamics of ice flow. Interactions between meltwater, ice flow and subglacial sediments give rise to a unique assemblage of periodic subglacial landforms composed of sediments known as bedforms. These subglacial bedforms therefore provide a large-scale observational window into the subglacial environment, which is difficult to analyze beneath current ice masses.
Mapping subglacial bedforms is traditionally performed using digital elevation models (DEMs) and/or aerial or satellite imagery through manual digitization in GIS software. This method is time-consuming and introduces operator subjectivity, heavily dependent on the expertise level of the operator. This manual approach is also a significant barrier to the use of new datasets with increasingly higher resolution (e.g. ArcticDEM, RGE ALTI®, HiRISE) and coverage of ever larger areas. Addressing these limitations is essential to efficiently analyze the distribution and morphometry of subglacial bedforms over large territories.
To overcome these challenges, we designed an automated tool to delineate and analyze the shape of subglacial bedforms using a recently defined land surface parameter, the Volumetric Obscurance. This parameter highlights convex and concave surfaces while minimizing the impact of noise from the topographic signal, making it particularly suited for detecting and mapping subglacial morphologies. The automated tool is based on the assumption that the diversity of subglacial bedform shapes reflects a continuum: therefore, unlike traditional methods, no pre- or post-mapping classification of bedforms is performed.
Our method uses DEMs and optical satellite images, including ArcticDEM and Sentinel-2 data, to generate regional morphological maps (bedform outlines and crestlines) and regional morphometric maps (spatialized statistical analysis of bedform morphometrics). It employs a multi-threshold segmentation approach to extract bedform features and calculate both dimensional morphometric parameters (e.g., volumes, areas) and dimensionless parameters (e.g., sinuosity, circularity, elongation). These provide synthetic and spatialized information on the distribution of morphological parameters across entire bedform fields.
We tested the tool on ArcticDEM data over a portion of the former Laurentide Ice Sheet bed, specifically the Keewatin Dome region in northern Canada, which displays a wide diversity of bedform shapes. The produced morphological maps demonstrated strong consistency, with approximately 75% correspondence between individual bedform outlines generated automatically and reference maps manually digitized by two distinct glacial geomorphologists. Despite a 25% difference in individual bedform outlines, the derived morphometric maps were highly comparable and provide reliable insights into subglacial deformation and hydrology.
By reducing subjectivity and significantly accelerating the mapping process, this tool enables the analysis of larger areas with greater precision compared to manual methods. The derived datasets allow for reconsideration and refinement of ice-sheet scale reconstructions of ice flow and meltwater dynamics. The tool is developed in Python and is freely accessible to the research community.

How to cite: Hesni, S., Bessin, P., Ravier, E., Bourgeois, O., Vérité, J., and Buoncristiani, J.-F.: Automated delineation and morphometry of unclassified subglacial bedforms., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8508, https://doi.org/10.5194/egusphere-egu25-8508, 2025.

Geomorphological maps are essential tools for understanding landscape evolution and natural hazards in mountain environments. However, their creation requires substantial time investment and expert knowledge, limiting the availability of up-to-date mapping products. While automated mapping approaches have been developed for selected individual landforms, no spatially exhaustive method exists for the complex terrain of high alpine environments. To overcome this, we evaluated different CNN models, achieving state-of-the-art results for semantic segmentation, for automated geomorphological mapping. For the training we created homogenized maps of three alpine valleys covering more than 170 km² and comprising 20 landform classes. As input layer we tested various three-band raster composites, consisting of various combinations of digital elevation model (DEM) derivatives like topographic openness or terrain wetness index.

Preliminary results show that several models achieve F1 scores exceeding 0.8 for the most relevant geomorphological features, including ground moraine, rock glaciers, lateral moraines, and fluvial terraces. Lower performance was observed for narrow and shallow landforms and anthropogenic features like streets and buildings. However, anthropogenic features are often underrepresented in high alpine valleys explaining their worse performance. Hence, our results indicate that additional manual correction is necessary to use these automatically derived maps in downstream tasks. However, the time required to create geomorphological maps of consistent quality, on the basis of these automatically derived maps, can significantly be reduced. This enables rapid geomorphological mapping in previously unmapped high alpine catchments and facilitates the creation of multitemporal maps within single study areas. The latter application opens new possibilities for quantifying structural changes in alpine geomorphic systems over time, contributing to our understanding of landscape evolution and response to climate change.

How to cite: Himmelstoss, T., Mikolka-Flöry, S., Haas, F., Becht, M., Pfeifer, N., and Heckmann, T.: Evaluation of convolutional neural networks (CNNs) for the automatic generation of geomorphological maps in high alpine environments, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8600, https://doi.org/10.5194/egusphere-egu25-8600, 2025.

For 15 years, TopoToolbox has provided a platform for quantitative geomorphology. Its extensibility, user-friendly interface and comprehensive documentation have enabled users across the geosciences and around the world to build custom data analysis and modeling workflows in MATLAB. The third version of TopoToolbox builds on this legacy by making it accessible from other programming and data analysis environments and implementing sustainable research software engineering practices to ensure that TopoToolbox will continue to provide a stable foundation upon which to build geoscientific data analysis tools.

The new software architecture factors the fundamental TopoToolbox algorithms into a separate library that can be accessed from other programming languages such as Python and R while maintaining the existing MATLAB toolbox. Interoperability with the existing geospatial software ecosystems in these languages is encouraged by exposing a minimal interface to a few key data structures and composing transformations between these data structures. This architecture has already allowed us to integrate new tools such as the GraphFlood hydrodynamic model (Gailleton et al. 2024) with TopoToolbox.

Accompanying these software changes has been a reorganization of the software development workflow. Extensive automated testing ensures consistent behavior across languages and helps prevent the introduction of bugs throughout the refactoring process. Modern testing methodologies like property-based testing make it possible to test TopoToolbox even when the correct outputs of our algorithms are unknown. TopoToolbox is developed publicly on GitHub (https://github.com/TopoToolbox), and we encourage contributions from members of the community.

How to cite: Kearney, W., Schwanghart, W., Lamprecht, A.-L., Scherler, D., Bringezu, T., Bartha, D., and Gailleton, B.: TopoToolbox 3 -- a laboratory for topographic analysis, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8678, https://doi.org/10.5194/egusphere-egu25-8678, 2025.

The availability of 3D data in geology, especially in geomorphology, has increased tremendously in the past years. Airborne lidar data, large-scale UAV surveys using Structure-from-Motion approaches, or virtual outcrops generated from hand-held cameras allow a much finer quantitative description of the Earth’s surface. New analysis techniques for geomorphology are actively developed to explore and take advantage of data structures and higher resolution.

This presentation will showcase some recent examples of data collection strategies in the field, but also segmentation and feature generation on dense point clouds and high-resolution orthomosaics. Point clouds often sample objects very densely and form nearly continuous surfaces - 3D coordinates can be converted into a network structure to form meshes, which are spatial data structures containing slope and aspect information for every facet that links three points. The view angle of lidar scanners or cameras during Structure-from-Motion processing can be used to orient normals of points and meshes. As an application example, we use curvature measured along mesh surfaces for 3D segmentation of pebbles and grains. Meshes are also data structures for measuring volumetric differences, for example between pre- and post-event data acquisitions. Textured 3D models are not yet used in the geosciences, but provide opportunities to include spectral and roughness information on meshes.

A current challenge in the processing of point clouds is the precise classification of points, such as distinguishing between ground and vegetation points. A common approach is to calculate geometric features in a spherical neighborhood and use these as an input to a classifier such as a random forest or a neural network. Here, we show an alternative approach for deriving point neighborhoods to calculate features for point-cloud classification: Instead of using all points in a neighborhood, we select points based on point attributes such as normal direction, color, or point connectivity. A feature-based classification based on these modified neighborhoods shows improved classification accuracy. 

By highlighting two approaches in point-cloud processing - turning point clouds into meshes containing network information and carefully selecting neighborhoods for point-feature calculation - we show the potential that point clouds have in geomorphologic applications.  An open research area is to further improve classifications for environmental point clouds to better monitor and quantify processes in the geosciences.

How to cite: Bookhagen, B., Rheinwalt, A., and Hess, M.: Point Clouds, Voxels, Meshes, and Beyond: Examples for 3D Data Processing in the Environmental Sciences, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10879, https://doi.org/10.5194/egusphere-egu25-10879, 2025.

To assess the grain-scale morphology and size distribution of sediments which are important factors controlling the erosion efficiency, sediment transport and the aquatic ecosystem quality, we developed the G3Point algorithm to extract grain information from 3D point clouds. Field measurements can be very tedious and G3Point is a semi-automatic and non-destructive method developed to tackle the determination of the grain-scale shape of sediments in geomorphology. Initially developed with Matlab, G3Point i) segments a given 3D point cloud with sufficient resolution into individual sub-clouds, ii) fits ellipsoids to the sub-clouds and iii) computes metrics not only on the size and shape of grains but also on their orientation and organization. Unfortunately, the ergonomics of the Matlab code are not optimal to process and visualize 3D points clouds. The interaction with the user is based on scripts, Matlab is limited in terms of point clouds visualization functions, and it is not possible to edit point clouds directly in the graphical interface.
CloudCompare is a powerful free software for 3D point clouds and triangular meshes processing. Thanks to its plugin mechanism, we have fully integrated G3Point into the main application. It is available easily through the graphical user interface making the processing very productive and practical. The first step of G3Point, based on a trial-and-error approach, is much simpler with the plugin. Furthermore, even with a satisfying set of parameters, the segmentation needs often to be refined and CloudCompare allows to edit directly the point cloud. As CloudCompare includes many advanced tools for registration, resampling, color/normal/scalar fields handling, statistics computation and display capabilities, it is now possible to prepare data, precisely visualize them, apply G3Point and post process them with a single tool.

How to cite: Leroy, P., Steer, P., Guérit, L., and Lague, D.: Leveraging CloudCompare to measure grain geometries from 3D point clouds: a plugin for the G3Point algorithm, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15463, https://doi.org/10.5194/egusphere-egu25-15463, 2025.

Landslides are among the most frequent natural hazards, posing threats to human lives, infrastructure, and the environment. Effective mitigation of the associated risks requires improved landslide understanding based on high-resolution data.               
Digital twins, created using optical or LiDAR-based remote sensing techniques alongside the derived digital terrain models (DTMs), offer significant potential to enhance landslide modeling and therefore deepen our understanding of their dynamics. However, the generation of such 3D models remains challenging in forested areas as most remote sensing techniques, particularly those utilizing aerial platforms, lack the ground point density needed to capture the surface precisely. Additionally, ground point classification (GPC) becomes more difficult at increasing resolution and forest cover.

To address these challenges, we explore novel under-canopy ground data acquisition methods for digital twin generation and present innovative approaches for DTM generation and refinement, along with digital dendrogeomorphology.         
Conducted at a representative study site, close-range panoramic terrestrial photogrammetry (_crpTP) and terrestrial laser scanning (_crpTLS) were employed and evaluated for their effectiveness in generating high-resolution 3D models. We utilized a custom R-tool applied to the derived point cloud for ground surface extraction and refinement. The presented script overcomes challenges in DTM generation from high-resolution point clouds by correcting misclassifications typical in the GPC process at fine scales, using a combination of tree detection and generalized additive modeling. Additionally, we analyse the morphology of detected trees by automatically fitting least square ellipses to stem segments and deriving the shape, eccentricity, inclination, and tilting direction of tree stems. This data-driven, digital approach to dendrogeomorphology offers potential solutions to current challenges in conventional dendrogeomorphological surveys, such as time and labour intensiveness or bias in the selection of sample and reference trees.

Our study demonstrates that both _crpTP and _crpTLS are capable of producing highly accurate digital twins of forested landslides. The models generated through photogrammetric data acquisition for two small-scale test plots are characterized by low check point RMSE values ranging from 0.16 to 0.19 cm, indicating high model accuracy. In comparison, the _crpTLS digital twin of the entire study area showed an RMSE value of 1.87 cm. The accuracy of the derived DTMs, validated using independent sets of ground reference points, ranged from 0.92 to 1.90 cm. The high filtering accuracy demonstrated the capability of the presented approach to reduce misclassification and propagation errors in the generated DTMs.      
By employing digital dendrogeomorphology, we were able to fit least square ellipses to stem segments at RMSE accuracies close to the voxel size of the point cloud. Based on these accurately fitted ellipses, their respective centroids and shift across stem segments, we demonstrate the feasibility of automatically extracting tree morphology indicators.

Our study shows that the combined extraction of DTMs and tree morphology indicators from digital twins can provide valuable data on both surface and subsurface processes, which, when applied over multiple time periods, can enhance landslide understanding. However, as the study site is characterized by little understory, the applicability at other sites with different forest structures has yet to be explored.

How to cite: Müller, B. and Kamaryt, T.-H.: Advancing Landslide Understanding in Forested Areas: High-Resolution Digital Twins for Novel DTM Extraction and Digital Dendrogeomorphology, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15955, https://doi.org/10.5194/egusphere-egu25-15955, 2025.

Most of the global actions for sustainability focus on the biosphere, overlooking the role of abiotic components, embedded in and supported by the geosphere and its ecosystem services [1]. As a consequence, proxy for geodiversity evaluation can act as indicator of areas with a strong propensity for naturalness, enhancing their protection and promoting conservation strategies. Geodiversity assessment depends on the size of the study area, the nature and resolution of available data, and the choice of an empiric or a quantitative method to define a categorical geomorphodiversity index [2]. Geomorphodiversity, a simpler but meaningful quantity, describes the diversity of landforms in an area, resulting from the surface processes modelling the landscape.

We recently defined a geomorphodiversity index (GmI) considering a few morphological features derived from digital elevation models: slope angle, drainage density, and landforms (through the geomorphons model [3]), as an approximation to field-observed features, and lithological information, as descriptors of the geological constraints and geomorphological processes of the landscape. Compared to previous approaches [4-6], we introduced a scale–independent method that considers contributions of the partial diversities of the four descriptors, calculated through focal statistics with a range of radii. The partial maps were classed, combined, and classified again into a raster with five final GmI classes. We dropped the dependence from the window radius by combining the set of radius–dependent GmI maps into a single map, selecting for each cell the most common value across the set of maps [7]. This approach has the advantage or removing the parameter dependence and embedding information from different scales in each grid cell of the GmI, which makes it suitable for and suitable accuracy for national, regional and urban scale analysis [8].

We implemented the method in a simple and versatile GRASS GIS procedure, suitable for implementation in a general-purpose raster module. The software accepts a variable number of raster or vector layers, and for each layer it calculates partial diversities with the desired working resolution and a user-defined number of different radii for focal statistics. The software combines intermediate layers with different weights, defined by the user based on the available geomorphological information, and reclassified into a final geomorphodiversity index.

Results show that such GmI proxy can reproduce the essentials of the observed distribution of landforms, using a small number of widely available datasets. We consider the proposed GmI map as a discrete measure of richness and variability of abiotic components, providing an intuitive information, readily available for subsequent applications in different locations and at different resolutions.

References

[1] Schrodt et al., PNAS (2019). https://doi.org/10.1073/pnas.1911799116

[2] Zwoliński et al., Geoheritage (2018). https://doi.org/10.1016/B978-0-12-809531-7.00002-2

[3] Jasiewicz & Stepinski, Geomorphology (2013). https://doi.org/10.1016/j.geomorph.2012.11.005

[4] Benito-Calvo et al., Earth Surf. Proc. Land. (2009). https://doi.org/10.1002/esp.1840

[5] Melelli et al., Sci. Tot. Env. (2017). https://doi.org/10.1016/j.scitotenv.2017.01.101

[6] Burnelli et al., Earth Surf. Proc. Land. (2023). https://doi.org/10.1002/esp.5679

[7] Burnelli et al., Geomorphology (2024). https://doi.org/10.1016/j.geomorph.2024.109532

[8] Burnelli et al., Geomorphology (2024). https://doi.org/10.1016/j.geomorph.2024.109582

How to cite: Burnelli, M., Melelli, L., and Alvioli, M.: A multiscale approach for geomorphodiversity indices on large areas, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17089, https://doi.org/10.5194/egusphere-egu25-17089, 2025.

Agricultural terraces are among the most significant anthropogenic land modifications in the Mediterranean. They are constructed to reduce local slope gradients and facilitate farming by artificially increasing soil thickness. Terraces also reduce soil erosion and enable irrigation practices. Yet, if not maintained or abandoned, they become prone to piping, gully erosion, and landsliding. Nevertheless, incorporating these effects into large-scale hydrological, geomorphological, and agronomic research remains challenging due to limited information on terrace locations and characteristics.

We aim to address this gap by presenting a new predominantly automatic approach for detecting and classifying terraced units on a large scale. This scalable tool utilizes freely available data: Google optical satellite imagery (≈2.1 m spatial resolution), ALOS Global DSM (30 m spatial resolution), and ESA WorldCover (10 m spatial resolution). Our study site, Cyprus, with an area of 9,250 km² has a long history of terraced agriculture driven by its rugged terrain. The island features terraces ranging from old, abandoned ones to newly constructed terraces using heavy machinery.

The approach employs Object-Based Image Analysis (OBIA). First, images are segmented using SLIC (Simple Linear Iterative Clustering). These segments are populated with information from 22 derivative layers generated from the initial data. For each segment, 36 statistical parameters are calculated. The derived layers include slope, curvature, Gray-Level Co-Occurrence Matrix (GLCM) features, Canny edge detection results.

To ensure robust classification, the data was split into tiles, with some used for training and others for validation to minimize spatial autocorrelation. The model was trained using AutoGluon, focusing on CatBoost and Neural Networks. The binary classification achieved a ROC-AUC value of 0.87 and a Matthews Correlation Coefficient (MCC) of 0.44. Subsequently, detected terraces were classified into three morpho-functional classes. Broad agricultural terraces were identified with high accuracy (0.84). Narrow agricultural terraces on steeper slopes with stone walls showed moderate performance (accuracy = 0.72). However, distinguishing narrow terraces built for reforestation from agricultural terraces in similar conditions proved challenging (accuracy = 0.46).

Our results demonstrate the potential for developing detailed, large-scale terrace datasets. This, in turn, opens promising perspectives to better assess soil erosion and other geohydrological processes at such scale.

How to cite: Kedich, A., Vandam, R., Verstraeten, G., Vervust, S., Devos, Y., and Vanmaercke, M.: Automatic mapping of terrace systems at large scales: a case study of Cyprus, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17335, https://doi.org/10.5194/egusphere-egu25-17335, 2025.

Surface roughness is an important control on a wide range of Earth surface processes. The increasing spatiotemporal availability of topographic point cloud data provides scope for advances in quantifying geomorphic surfaces and topography. Here, bedrock riverbed point clouds were obtained from dry riverbeds using terrestrial laser scanning (TLS) and Structures from Motion (SfM) photogrammetry. These data were processed using a unified workflow to extract the channel morphology and multiple different surface roughness. Metrics were calculated based on vertical and horizontal point spacings, cell area and slope, and incorporated multiscale analysis methods. Principal component analysis and hierarchical clustering revealed the concurrent use of multiple metrics is required to comprehensively describe the diversity in bed topographic characteristics. Multiple metrics are required as riverbed characteristics and features are shown to be represented by differing surface roughness metrics. This work further explores the applications of these metrics to advance the understanding of geomorphic and Earth surface processes, including sediment transport processes and hydrodynamics. It is proposed these metrics and analysis approaches can be applied more widely to landscapes beyond riverbeds, yet the most appropriate metric likely depends on the process that is of interest.

How to cite: Houseago, R., Hodge, R., Ferguson, R., Hackney, C., Hardy, R., Hoey, T., Johnson, J., Rice, S., Yager, E., and Yamasaki, T.: Quantifying riverbed surface roughness from point cloud data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18204, https://doi.org/10.5194/egusphere-egu25-18204, 2025.

The development of low-cost sensing systems for 3D data collection has revolutionised geomorphic research. High-resolution 3D data can now be collected, processed on-site, and analysed with ease, thanks to advancements in devices such as iPhone/iPad LiDAR sensors and the processing of Structure-from-Motion (SfM) data on a mobile phone. Despite these advances, systematic comparisons between low-cost methods and industry-standard techniques, such as Terrestrial Laser Scanning (TLS), remain limited, particularly in fluvial environments.

This study evaluates the efficacy of multiple low-cost 3D monitoring methods, including iPad LiDAR, mobile phone SfM, and digital SLR SfM, against TLS in a fluvial context. Six leaky wooden dams, widely used as natural flood management interventions across the UK, were selected as monitoring subjects. These dams significantly impact river hydrology, sediment transport, and geomorphic evolution, yet the lack of repeat monitoring limits our empirical understanding of their effects.

Our results quantify the spatial errors associated with each low-cost technique, offering critical insights into their applicability for geomorphic data collection. Additionally, this work establishes the first accessible, spatially distributed database of high-resolution surveys of leaky wooden dams. This database provides a valuable foundation for future research and enables academics, industry, the third sector, and the public to contribute to a global record of geomorphic change. By demonstrating the untapped potential of low-cost sensing technologies, this study promotes more widespread, cost-effective monitoring of geomorphic processes.

How to cite: Wolstenholme, J. and Houseago, R.: Quantifying the spatial error of low-cost 3D monitoring, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18866, https://doi.org/10.5194/egusphere-egu25-18866, 2025.

Physical scale experiments of natural systems such as debris flows, rivers, estuaries and deltas are conducted within the geosciences to enhance our understanding of the physical processes on Earth. Methods in these experiments are under continuous development, often inspired by the advancements in remote sensing, making use of e.g. overhead fixed position cameras, movable gantry mounted cameras and line laser scanners, which are analogous to fixed-camera timelapses, drone surveys, and LiDAR, respectively. However, physical scale experiments come with additional challenges, as small uncertainties in positioning and orientation of the sensors can significantly bias the experimental results, especially because the small-scale morphology is typically in the order of a few centimeters. Moreover, photogrammetric data processing is prone to doming which can vary for each timestep, impeding change detection studies.

We will present the advancements in the data processing of our 20 by 3 m laboratory facility that is used to emulate tidal cycles to induce morphological development in coastal systems (www.uu.nl/metronome). Mounted ~4 m above our facility are 7 lower-grade overhead cameras (pixel resolution ~1.5 mm, overlap ~20%) which are simultaneously triggered at each tidal cycle. Additionally, when an experiment is paused, we conduct both DSLR surveys (pixel resolution ~0.5 mm, overlap ~80%) and 3D laser triangulation system surveys producing gridded data (planimetric resolution ~1 mm), along a movable gantry system. We have built a large dataset of >220.000 experimental tidal cycles and >2.000.000 unique images, which requires fully automated data processing that results in morphology which is consistently accurate in both the spatial and temporal domains of our timeseries.

We developed an extensive data processing workflow that incorporates a base model of our facility under idealized conditions. This base model was photogrammetrically constructed in Agisoft Metashape by aligning a total of 169 images from all cameras without downscaling. Through an automated and fast-performing python script, we are able to successfully align this base model to our complete dataset of DSLR-gantry surveys to generate orthomosaics and DEMs, as well as overhead imagery to generate timelapses of orthomosaics. This method shows a striking degree of robustness, because it has no difficulty with aligning 7 unique overhead cameras with limited overlap, as well as imagery of increasingly different morphology compared to the base model.

Finally, positions (X,Y,Z) and orientations (ω,φ,κ) of the cameras along the gantry were extracted from the base model, which were implemented in a new workflow that processes the raw laserscan data using vector algebra and transformation matrices. This results in DEMs that are geometrically aligned to the base model, without the use of a photogrammetric method. Accordingly, these DEMs have no variability in doming throughout the timeseries and therefore a higher temporal accuracy. Moreover, the implementation of variability in camera positions and orientations results in an improvement in altimetric accuracy from 7 to 2 mm (99.7% confidence), significantly reducing the bias in small-scale morphology. Our methods can be partially or fully implemented in research and industry using small to medium scale setups of both fixed and gantry-mounted camera systems.

How to cite: Nota, E., van Amstel, B., Nijland, W., van Maarseveen, M., and Kleinhans, M.: Multiple-sensor photogrammetric base model alignment of large timeseries in physical scale experiments, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19352, https://doi.org/10.5194/egusphere-egu25-19352, 2025.

In this study, we present a comprehensive analysis of landforms derived from a 10-meter resolution digital terrain model (DTM) using unsupervised classification with different combination of morphometric variables and established algorithms, including the Topographic Position Index (TPI; Weiss, 2001) and Geomorphons (Jasiewicz & Stepinski, 2013). These methodologies allowed us to delineate distinct landforms, which were subsequently subjected to detailed spatial and statistical analyses to evaluate their geomorphological characteristics and interrelationships. Specifically, we aim to compare how different landform classifications, derived from these approaches, correlate with geothematic variables such as lithology, engineering geological characteristics, and the distribution of shallow landslides. To statistically assess the congruence between landform classifications and geothematic variables, we applied statistical tests such as chi-square tests for independence (for categorical variables) which is used to determine whether there is a significant relationship between landform classes and categorical geothematic variables. Moreover, the strength and direction of these relationships are further evaluated using Cramér’s V. These tests provided insights into the relative effectiveness of each different landform classification in describing the variability of geothematic variables. The study was conducted in northern Tuscany, a region characterized by a complex interplay of geological, morphological, and climatic factors that make it particularly susceptible to shallow landslides and debris flows. These phenomena are frequently triggered by intense rainfall events, which highlight the importance of understanding the distribution of predisposing factors for slope instability in such areas. In conclusion, this study explores different methods to perform the landform classification and establishes a framework to evaluate how they are related to independent geothematic variables, which may be used to assess landslide susceptibility and hazard.

How to cite: Pippi, M., D'Addario, E., Masoni, G., Marques e Silva Rocha de Oliveira, E., and Disperati, L.: The performance of different landform classification methods as assessed by their relationship with geotemathic variables, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19353, https://doi.org/10.5194/egusphere-egu25-19353, 2025.

Many landscapes are characterized by marked differences in rock erodibility. Cuesta and escarpment landscapes, for example, develop their characteristic form due to contrasts of physical and chemical properties of individual rock layers in lithostratigraphic sequences. Over long time scales, 3D-variable rock properties and resistances to erosion imply that landscapes do not attain a steady state and exhibit autogenically migrating drainage divides. One may thus argue that landscapes with layered rocks are much more dynamic than landscapes characterized by homogenous rocks. Here, we present the development and implementation of TTLEM3D, an enhancement to TTLEM based on TopoToolbox which relies on the detachment-limited stream-power incision model and the eikonal equation to simulate eroding landscapes characterized by spatial variations in rock erodibility and threshold slopes. We show that 3D variations in rock properties strongly affect how landscapes respond to changes in uplift rates and uplift patterns. While simulated elevations compare well with the topography of actual landscapes, we note several discrepancies that reflect theoretical shortcomings of geomorphic transport laws and their application in landscapes with layered rocks.

How to cite: Schwanghart, W., Kearney, W. S., Rau, M., and Scherler, D.: TTLEM3D - Simulating erosion of uplifting landscapes with layered rocks , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20069, https://doi.org/10.5194/egusphere-egu25-20069, 2025.

Bathymetry is a critical component in many geomorphological and ecological studies of coastal and fluvial environments. Bathymetric lidar remote sensing enables the acquisition of high-resolution, 3D data on shallow sea- and riverbeds, thus providing precise modeling of their topography. However, in certain contexts, the optical interactions between light and water make extracting bathymetry from lidar signals particularly challenging, resulting in incomplete bed coverage. This is the case in very shallow waters at the transition between land and water – where the signals of the water surface, column, and bottom become entangled – and in deep or turbid waters, where signal extinction hinders the detection of the sea- or riverbed.

In this work, we explore new approaches for bathymetry extraction from lidar waveforms across diverse environments. With temporal convolutional neural networks, we show improvements in detecting the position of the sea- or riverbed using bathymetric lidar waveforms. Our experiments, conducted on simulated data representing a wide range of environmental conditions – varying turbidity, depth, and reflectance – yield promising results. They highlight the potential to extract the position of the sea- or riverbed even in simulated waveforms with low signal-to-noise ratios or highly overlapping signals – cases that have posed challenges for existing processing methods. Given the increasing popularity of bathymetric lidar, particularly with the advent of UAV-mounted sensors, enhancing waveform processing methods could help advance the surveying of submerged areas.

How to cite: Letard, M., Corpetti, T., and Lague, D.: Extracting bathymetric information from LiDAR waveforms with 1D neural networks., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20513, https://doi.org/10.5194/egusphere-egu25-20513, 2025.

Suspended sediment concentration (SSC) significantly impacts water quality, aquatic ecosystems, and reservoir capacity, making accurate prediction vital for effective watershed management. Traditional empirical and physically based models often struggle to handle the complexities and non-linear dynamics of sediment transport. Machine learning (ML) techniques, with their ability to model non-linear relationships and process large datasets, offer a promising alternative. This study explores the application of ML models, including extra trees (ET), random forest (RF), categorical boosting (CatBoost), and extreme gradient boosting (XGBoost) and their combination with genetic programming (GP), to predict SSC. Key environmental variables such as precipitation, streamflow, and seasonality are used as inputs, and the models are trained and validated using historical hydrological data. The SHapley Additive exPlanations (SHAP) framework is employed to interpret the models, offering insights into the influence of each input variable on SSC predictions. Results demonstrate that ML models outperform traditional approaches in accuracy and robustness, particularly in capturing peak sediment events. The findings underline the potential of ML in improving SSC prediction and guiding sustainable watershed management practices.

Keywords: Suspended Sediment Concentration (SSC), Machine Learning (ML), SHAP Values, Hydrological Modeling, Sediment Transport, Watershed Management.

How to cite: Lamane, H., Mouhir, L., Moussadek, R., Baghdad, B., and El Bilali, A.: Leveraging Machine Learning for accurate and interpretable suspended sediment concentration predictions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-629, https://doi.org/10.5194/egusphere-egu25-629, 2025.

Quantifying sediment transport dynamics in Alpine rivers is essential for predicting their geomorphological evolution, for managing flood risks and fluvial ecosystems, as well as for sustainable management of hydropower schemes. However, actual data on sediment transport, particularly for the bedload fraction, are often very scarce (if not absent altogether) due to the challenges inherent in collecting such information. Thus bedload transport dynamics have to be predicted at the basin scale by relying on limited (in space and time) field observations. However, models capable of simulating bedload transport at the network scale in mountain rivers are very few, and to the best of our knowledge, their validation has never been carried out.

The primary objective of this research is to evaluate the performance of the D-CASCADE model – after adapting it to work in Alpine rivers – to simulate bedload transport dynamics at a network scale in the Sulden/Solda river basin (Italian Alps). The Sulden catchment was selected due to the sediment transport monitoring station present at its outlet (130 km²) as well as for the long duration of bedload transport throughout the year due to its nivo-glacial hydrological regime. Since 2014, bedload transport has been continuously monitored in the Sulden River using geophones, which provide high-frequency data on bedload movement and capture temporal variations in bedload transport. To calibrate the geophone signals, regular bedload sampling was conducted. The data obtained from these samples provided detailed insights into the grain size distribution of the transported material at the outlet reach of the modelled network. This empirical information was crucial in fine-tuning the adapted D-CASCADE model and refining existing transport capacity formulas to characterize the connectivity properties of the Sulden network in terms of bedload flux dynamics, path lengths and velocities as well as sediment budgeting of the different reaches.

Preliminary validation of the adapted D-CASCADE model shows a promising agreement between predicted and observed bedload transport rates at the monitoring station. The model demonstrates the potential in reconstructing bedload transport patterns across the entire river network, identifying key sediment sources contributing to the overall sediment flux. Additionally, the model illustrates the spatial and temporal variability in bedload transport, highlighting the complexity of sediment dynamics in Alpine rivers.

How to cite: Pitscheider, F., Argentin, A.-L., Doolaeghe, D., Gianini, M., Repnik, L., Bizzi, S., Lane, S. N., and Comiti, F.: Network-scale modelling of bedload transport in Alpine rivers using D-CASCADE model, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5869, https://doi.org/10.5194/egusphere-egu25-5869, 2025.

Understanding sediment transport routes is crucial for predicting geomorphic changes driven by natural and anthropogenic processes in coastal and fluvial systems. Sediment tracing methods are vital to gain such understanding, but common sediment tracers are usually limited to following sediment released from a specific point. In our TRacking Ameland Inlet Living lab Sediment (TRAILS) project, we explore the use of natural luminescence signals of minerals to trace nourished sediment grains on an ebb-tidal delta. Towards this, we obtained and analyzed sediment samples from the Dutch Wadden Sea, where a mega-nourishment in the Ameland inlet ebb-tidal delta aims to address the sediment demand of the nearby coast and basin.

Insufficient luminescence signal resetting, e.g. poor bleaching, due to limited light exposure, can serve as a tool for sediment tracing by examining variations in the degree of bleach characteristics of luminescence signals with differing bleaching sensitivities within a single grain. This can inform us about light-exposure of that grain and therefore about sediment transport history, as explored by Reimann et al (2015) for a beach nourishment project at the Dutch coastline. Firstly, we hypothesize that slow-to-bleach signals reveal information about the end-member type: native grains in our ebb-tidal delta will be well-bleached in comparison to nourished grains. Secondly, we hypothesize that fast-to-bleach signals give insight into the transport history of grains: native grains will be more or less fully reset within the dynamic tidal reworking system of the Wadden Sea whilst nourished grains will still inherit part of their original signal. Combining information derived from slow- and fast-to-bleach signals thus provides a promising novel approach for tracing sediment grains in dynamic subaqueous environments, and thereby reveals sediment transport pathways of nourished sand grains.

Luminescence tracing methods rely on quantitative information about the potential and efficiency of subaqueous signal resetting. In a one-day experiment we quantified bleaching potential, that is, the light intensity and spectrum as a function of time, depth and tidal stage, and bleaching efficiency, that is the degree of bleaching of slow- and fast-to-bleach luminescence signals (de Boer et al., 2024a). Strongest subaqueous light attenuation took place during low tide when sediment concentrations are the highest, we also observed stronger attenuation of the ultraviolet part of the light spectrum. Light-sensitive luminescence signals, such as low-temperature feldspar IRSL, bleached more rapidly than less light-sensitive signals, such as high-temperature feldspar post-IR IRSL. None of the investigated signals were fully reset after 13.5 hours of light exposure, even for subaerially exposed samples. We then collected and analyzed over 100 sediment samples from the Ameland ebb-tidal delta. Using an EMCCD camera (de Boer et al., 2024b), we imaged a multitude of single-grain luminescence signals to explore the native or nourished origin of these sand grains. Ultimately, we aim to integrate these findings with Lagrangian sediment transport models to better understand spatial and temporal coastal sediment dynamics and inform coastal nourishment strategies (Pearson et al., 2022).

How to cite: de Boer, A.-M., Pearson, S. G., Pannozzo, N., Kooistra, T. J., van Prooijen, B., and Wallinga, J.: Luminescence imaging of single grains of sand reveals their sediment transport history, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6632, https://doi.org/10.5194/egusphere-egu25-6632, 2025.

Predicting the flow conditions required to entrain sediment in gravel-bed rivers is essential for many issues, such as river ecology, flood risk assessment, river restoration and sustainable river management, among many others. In this regard, the critical Shields parameter is the most commonly used metric to characterise particle entrainment in bedload transport studies. Consequently, the determination of critical Shields is fundamental to the prediction of bedload transport in gravel-bed rivers. Conventional field studies have focused on estimating a reach-averaged Shields stress, despite the large spatial variability that this parameter exhibits at the reach scale. This is largely due to the lack of standardised field approaches for characterising Shields stress in a spatially distributed manner. In this work, we propose a field-based procedure for estimating the frequency distribution of critical Shields at the patch scale in a gravel-bed river, based on the measurement of resistance to movement of individual clasts and a number of variables related to the position and orientation of grains. Following this procedure, we have approximated the patch-scale variability of particle entrainment conditions in a gravel bar of the Upper Cinca River, located in the southern watershed of the Pyrenees. The results (mean Shields ~0.03) are consistent with previous estimates of critical Shields in this river and with established theory of particle entrainment in gravel-bed rivers. We believe that this method has great potential to provide valuable field information on particle entrainment.

Ackowledgements: This research benefitted from the methods and outcomes of the MorphHab research project (PID2019-104979RB-I00/AEI/10.13039/501100011033, Ministry of Science, Innovation and Universities (MICINN), Government of Spain). The work by the first author is also part of the 2023–2026 grant signed between the Spanish Directorate General for Water (DGA-MITERD; Government of Spain) and the Spanish National Research Council (CSIC-Ministry of Science, Innovation and Universities), which includes action “Sedimentary Morphodynamics” (20233TE012: IGME-CSIC; Tarquín 2 Project).

How to cite: Vázquez-Tarrío, D., Carrero-Carralero, E., López, R., Ville, F., Vericat, D., and Batalla, R. J.: A field-based protocol to approximate variability in critical Shields coarse-bed rivers at the patch scale, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11090, https://doi.org/10.5194/egusphere-egu25-11090, 2025.

Understanding the variabilities of bedload mobility is fundamental in predicting the likelihood of erosion and deposition patterns in gravel bedded rivers, which subsequently assist towards modelling geomorphic adjustment and flood risk change over reach to catchment scales. In most applications, the shear stress required to initiate sediment transport (τ*_c) is typically assumed from relations with channel slope or the median bed material grain size, and is generally assumed temporally constant. However, flume investigations identify important relations between grain arrangement (for example, grain protrusion and imbrication) and sediment flux, which vary in response to flood history. Given the complexities of river systems, grain-scale linkages between water-working history, bedload characteristics, and grain mobility remain largely unexplored in the field.

We use a combination of gravel bed microtopography data, collected via structure-from-motion photogrammetry, and in-situ grain resistance tests to resolve a grain force balance model for 45 upland gravel surfaces across England and Wales. Grain resistance forces (F_R), and subsequent estimates of τ*_c, are used to explore grain scale drivers of particle mobility, as well as their spatial and temporal variabilities. We interpret flow histories of sampled surfaces using typical water-working indicators (including bed surface roughness, imbrication extent and grain size sorting). Water-working metrics are compared against resistance force distributions, to address the hypothesis that conditioned surfaces exhibit systematically higher mobility thresholds. We also consider the relative role of grain shape on bed topography and stability trends. In practical application, our findings can offer more targeted, process-based, estimates of τ*_c for a given channel reach, even when grain surface characteristics are only known qualitatively. Such improvements in τ*_c estimates are critical in furthering our ability to predict sediment fluxes and geomorphic change in gravel dominated channels, particularly in response to climate change, where the temporal sensitivity of τ*_c is likely to be important.

How to cite: Baynes, E., Whitfield, D., Rice, S., Jeffries, R., and Mathers, K.: Exploring Variabilities in Gravel Mobility Using Force-Balance Models, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11412, https://doi.org/10.5194/egusphere-egu25-11412, 2025.

The limited observational data on river bedload presents a significant challenge in understanding sediment transport processes. However, with recent advancements in computing capability, availability of remotely sensed data, and smart sensors, it is nowadays possible to model these transport processes in river networks at catchment scale. Nevertheless, the results of these models are often not robust due to inherited uncertainty and the stochastic nature of the input parameters. To manage these uncertainties and improve the robustness of model outputs, sensitivity analysis plays a crucial role. Sensitivity analysis is a method to study how changes in a numerical model's input factors contribute to variations in its output.

This project aims to apply Global Sensitivity Analysis (GSA) techniques to the D-CASCADE (Dynamic CAtchment Sediment Connectivity And Delivery) model, for the Po River network in Italy. D-CASCADE is a network-based (or graph-based) model that simulates material movement as distinct transport processes at the reach scale, or ‘cascades,’ defined by their provenance, sediment volume, and interactions downstream, at daily timestep.

To conduct the GSA, we use the SAFE toolbox, supporting both the generation of 5,000 random input factor combinations within defined ranges and distributions, as well as the quantification of the impact of each input factor's variation on the output.

In this work, we focus on the sensitivity estimation of active channel widths and riverbed slopes for every reach of the simulated network. These two input factors are key drivers of the transport capacity and the consequent sediment fluxes generated for the various sediment transport formulas implemented in D-CASCADE. The active transport width (the portion of the channel where bedload transport is active for a specific discharge) is largely unknown, even in data-rich contexts. Hydraulic slopes are also often unknown and generally replaced with topographic slopes which are largely dependent on the quality of the DEM used.  Active widths and slopes are then structurally inherently uncertain although they drive the model results. Through GSA, we evaluate how simultaneous random changes in these two input factors affect the simulated sediment fluxes and budgets. Results are analyzed both at the reach scale (sensitivity to local parameters) and the network scale (sensitivity to upstream parameters).

The presented methodology allows us to obtain important information about the effects of structural uncertainties in sediment transport modelling at network scale. These findings provide a foundation for enhancing the model's accuracy and resolving uncertainty in sediment transport prediction.

How to cite: Shrestha, S., Bozzolan, E., Doolaeghe, D., Surian, N., and Bizzi, S.: Enhancing sediment transport model reliability through Sensitivity Analysis: A Case Study in the Po River, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11920, https://doi.org/10.5194/egusphere-egu25-11920, 2025.

Predicting when riverbed sediment is mobile is essential for managing the morphology and ecology of gravel-bed river channels. However, our ability to predict critical shear stress (τ_c) is still such that predictions are only accurate to an order of magnitude at best. One aspect which is often overlooked when predicting grain entrainment, and which likely contributes to our poor predictions of τ_c, is the role of any cohesive material surrounding the gravel grains. This material could be clay, as is commonly found in gravel-bed rivers draining agricultural catchments, and/or biological, such as produced by caddisfly larvae, mussels and biofilms. To assess the potential impact of non-biological cohesion we parameterise a force-balance grain entrainment model to demonstrate that adding plausible values of cohesion can produce an order of magnitude increase in τ_c. We compare our results to two sets of field measurements of grain entrainment forces. The first set are from Bury Green Brook, UK, where there is local variation in the amount of clay matrix in the gravel bed and we assess differences in entrainment forces between individual grains. The second set comprises data from multiple sites with varying amounts of fines in the bed and we compare average entrainment forces. Our field data are consistent with the model results, demonstrating the potential importance of accounting for cohesion when predicting τ_c. Finally, we demonstrate that cohesive forces from clay are also sensitive to water content, and so may be most important in ephemeral channels.

How to cite: Hodge, R., Yager, E., Voepel, H., Leyland, J., Sear, D., and Sitorus, D.: The impact of cohesive material on gravel entrainment, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12444, https://doi.org/10.5194/egusphere-egu25-12444, 2025.

How to cite: Fiorucci, F., Santangelo, M., and Rossi, M.: Multiscale Sediment Connectivity Analysis in Clay-Dominated Lithology , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12946, https://doi.org/10.5194/egusphere-egu25-12946, 2025.

Catastrophic sediment release in fluvial systems is largely driven by landsliding that occurs naturally in mountain belts during extreme events, such as earthquakes or storms. Sediments are routed through the river system until they are stored either permanently in alluvial fans and lakes or temporarily in floodplains. The river response to such catastrophic sediment release has already been studied with 2D numerical models using a single effective grain size. Yet, in natural systems, the sediment grain size distribution can span several orders of magnitude and evolves during transport.

The role played by the grain size distribution on morphodynamics depends on transport modes and on grain size interactions. On one hand, fine sediments that tend to be transported in suspension and thus higher in the water column than coarse sediments contribute to floodplain formation and maintenance. On the other hand, coarse sediments that tend to be immobile or transported as bed load contribute to armouring of the channel bed surface that prevents its degradation and in turn leads to channel widening.

Assuming a single effective grain size may limit accurate forecasting of morphodynamic and sedimentological changes in rivers systems during landslide-induced sediment cascades. Modelling the response of a river reach in 3D, meaning that both morphodynamics (2D) and stratigraphy (1D) are resolved may be challenging due to computational time and computer memory. To cope with these limitations, we propose a 2.5D numerical model as a simplified approach. It incorporates: i) a multi-grain size sediment transport model with the ability to capture the transport of suspended and bedload material as well as the dispersion rate and sediment sorting patterns of various grain sizes such as armouring and downstream fining (threshold of motion and explicit grain-size specific entrainment and deposition rates), ii) an explicit transfer of sediment from the river channel to adjacent floodplains (based on the vertical distribution in the water column), iii) freely evolving channel width and slope, and iv) an algorithm to handle channel and floodplain sedimentary records (stratigraphic layers).

We conducted numerical simulations on a constricted river reach that consists of a straight channel with a floodplain on both sides. Numerical simulations reveal: i) how the grain-size specific signals propagate in a river reach and are preserved in the channel and floodplain stratigraphy in response to a catastrophic sediment release, and ii) how the channel width adjusts with stochastic flow conditions and sediment supply.

These preliminary results were obtained in the context of the SCALEES (Signature of sediment CAscades following Landslides triggered by Extreme Events in the Stratigraphy) project funded by the European Union. The combination of empirical data with numerical simulations will allow us to predict for the first time the full signal (all grain sizes) of sediment cascades preserved in stratigraphy in response to an extreme event at the scale of a catchment. It will also pave the way for inverting the stratigraphic record of landslide induced sediment cascades for quantitative insights into their response amplitudes and relaxation times.

How to cite: Le Minor, M., Lague, D., Howarth, J., and Davy, P.: Coupling a channel width evolution model and a multi-grain size sediment transport model: a simplified approach to predict the response of a river reach to a catastrophic sediment release, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14139, https://doi.org/10.5194/egusphere-egu25-14139, 2025.

The movement of sediment through river networks is crucial for the health and functionality of river ecosystems, flood control, and water availability. Network-scale sediment connectivity models have emerged in recent decades but lack robust validation with field measurements. Here, we perform a path length-based application of the morphological method, the Variational Mode Decomposition (VMD) method, to the Tagliamento River, a large braided river in northeastern Italy, to validate the sediment flux estimates generated by the network scale sediment connectivity model D-CASCADE.

The results indicate that D-CASCADE can generate sediment flux estimates that align with those derived from the VMD method and with values documented in literature. Furthermore, we observe that the generated path length estimates align with the expected path length based on the spacing of confluence-diffluence couplets which has been previously proposed as a proxy for path length. These results underscore the need for careful calibration of grain size distributions for specific rivers to improve model accuracy. Additionally, we identify the importance of estimating a fundamentally unknown input parameter, the active transport width (the part of the river channel where bedload is moving for a specific discharge), and its impact on the modeled sediment transport estimates. Finally, we see from the field acquisitions that even during small flood events on the Tagliamento, there is significant compensation when comparing the erosion and deposition volumes during each flood event.

These results demonstrate that the VMD method provides reasonable estimates of path length and sediment flux, thereby serving as a valuable validation tool for network-scale sediment connectivity models and increasing the robustness of the D-CASCADE model in large, complex river systems. The presented field data also help clarify when topographic changes are not a reliable representation of bedload fluxes due to high flow events or confined planform morphology, which then limits the applicability of the VMD method. Overall, the present study is a step forward in validating and refining our understanding of sediment transport processes in braided river environments and provides practical implications for the sustainable management of riverine ecosystems.

How to cite: Capito, L., Doolaeghe, D., Bozzolan, E., Surian, N., Bertoldi, W., and Bizzi, S.: Path Length and Sediment Flux Validation in Braided River Systems: Application of the VMD Method and D-CASCADE Model, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15136, https://doi.org/10.5194/egusphere-egu25-15136, 2025.

Soil erosion by water from upland areas results in on-site and offsite problems in the catchment and aquatic ecosystems such as lakes and rivers. As such, up-to-date information on erosion rates and suspended sediment fluxes in rivers is indispensable to manage the impact of soil erosion, sediment transport, and sedimentation. However, detailed spatial and temporal information on erosion and sediment dynamics is rare, as it is labor-intensive and costly to obtain, particularly in developing countries. The advent of satellite remote sensing applications has provided the opportunity to monitor sediment fluxes by assessing the suspended sediment concentration (SSC) of rivers and lakes. This approach may provide a cost-effective alternative to ground-based sampling schemes. However, satellite-based approaches to monitor sediment fluxes require calibration and validation as the relation between SSC and optical properties of the water recorded by satellite sensors may vary with changing sediment properties. 

Here, we used empirical models to estimate SSC values from optical sentinel 2 data for Lake Tana in Ethiopia using in situ collected water samples. Moreover, in situ reflectance data, which were measured using an ASD Field Spec 4 spectroradiometer instrument, from water samples collected at Lake Tana are used as well. SSC and in situ reflectance measurements were conducted for 546 water samples collected from the lake, particularly from the river plumes of the two most important rivers draining to Lake Tana, i.e. Gumara and Giligel Abay.  The sample SSC values ranged from 1.50 mg/L to 4,146 mg/L. The samples were classified into two categories:  low SSC (≤ 250 mg/L) and high SSC (> 250 mg/L), as the optical properties of water are significantly influenced by its constituents. The individual bands in the NIR and visible spectrum exhibited a good correlation (R² = 0.73, RMSE = 30.69 mg/L) for low SSC-values over Lake Tana. Moreover, the multilinear regression (MLR) analysis using both the visible and NIR bands of low SSC-conditions improved results compared to using individual bands (R² = 0.84, RMSE = 23.37 mg/L). In contrast, high SSC water samples from Lake Tana did not correlate well with individual bands. However, combining the NIR and red bands generally improved the estimation of SSC for high SSC values (R² = 0.9, RMSE = 0.26 mg/L).  

The established relations between optical properties and field-based SSC values will be applied to long-term timeseries of optical data to assess the temporal variations in sediment concentration in rivers draining to Lake Tana, and in Lake Tana itself. These timeseries will be compared to optical data on vegetation changes in the catchment to identify hot spots in both space and time that are responsible for elevated fluxes of sediment to Lake Tana. 

How to cite: Ashagrie Simegn, A., Worku Awoke, G., Annys, S., Frankl, A., and Verstraeten, G.: Estimation of suspended sediment concentration using satellite remote sensing data in Lake Tana, Ethiopia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15661, https://doi.org/10.5194/egusphere-egu25-15661, 2025.

The stability or, conversely, the mobilisation of riverbeds varies in time and space, making it a complex phenomenon to study. The size and intensity of mobile grains can lead to disturbance of the substrate that supports physical habitats and can therefore control the presence of aquatic organisms. The degree of mobility of a given grain size fraction (GSF) can be approximated by assessing the proportion of its grains that are mobile. On the other hand, the relative degree of mobility can be expressed as the ratio between the proportion p_i of this fraction among all mobilised grains compared to its initial proportion at the surface of the bed F_i. A condition of full mobility is reached when the fraction's proportion among the mobilised grains is equal to or greater than its initial proportion at the surface (p_i /F_i≥ 1). An underrepresented fraction is said to be partially mobile (p_i /F_i<1).

We present PhotoMOB, a GIS-based tool to characterise (i) grain shape (i.e. axis size, orientation, roundness, compactness, elongation), (ii) patch organisation (i.e. proportion of fine material cover, proportion of overlapping grains) and (iii) mobility magnitude of gravel river beds from repeated digital photographs taken before and after targeted hydrological events. It is based on the detection and the comparison of the shape of grains identified at the same coordinates (location). PhotoMOB allows identification of coincident grains (immobile) and new grains (mobile). Several variables can be extracted from this categorisation, such as: the overall proportion of mobile or immobile grains (in number or surface area), the maximum mobile or immobile diameters, the proportion per individual GSF of grains that remain immobile (stable) and newly identified grains. In addition, changes in fine material cover, grain overlap can be assessed and the percentiles of the surface grain shape distribution before and after a targeted hydrological event, as well as the distribution of exclusively immobile and/or mobilised grains, can be calculated.

Automatic classification applied to perfect (manual) digitisation of grains gives mean absolute errors for fractional mobility estimation of less than 3%, while automatic classification applied to automated digitisation with 10 minutes of manual grain boundary revision gives errors of around 8%. This approach has been developed, tested and applied in gravel-bed mountain rivers affected by hydropeaking, which induces partial mobility.

Ackowledgements: This work is carried out in the background of the projects MorphHab PID2019-104979RB-I00 / AEI / 10.13039/501100011033) and Undammed TED2021-130815B-C31 / MCIN/AEI/10.13039/501100011033, funded by the Spanish Ministry of Science, Innovation and Universities and the EU “NextGenerationEU”/PRTR. All authors are part of the Fluvial Dynamics Research Group –RIUS, a consolidated group recognized by the Generalitat de Catalunya (2021 SGR 01114). 

How to cite: Ville, F., Vericat, D., Rennie, C., and Batalla, R. J.: PhotoMOB: a GIS tool to monitor spatial and temporal bed mobility at the patch scale, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16407, https://doi.org/10.5194/egusphere-egu25-16407, 2025.

The suspended sediment concentration (SSC) in rivers is commonly indirectly estimated from optical turbidity measurements in one single point. Calibration based on regular sampling and laboratory analysis allows converting the optical turbidity into SSC. The regular sampling and laboratory analysis are time-consuming and expensive.

A hydro-acoustic multi-frequency approach has advantages as an alternative to optical turbidity measurements. Backscatter data collected with hydro-acoustic echosounders contains information on the suspended particles along an entire profile. The conversion of backscatter into SSCs from an acoustic single-frequency system, like most standard ADCPs are, requires knowledge on the characteristics of the suspended particles, in particular on their average size and the grain size distribution. These characteristics can be estimated by analysing water samples in the laboratory.

The present contribution reports measurements of the SSC along an entire profile with a multi-frequency system. The multi-frequency approach allows estimating the particle characteristics from the backscatter data. Hence, the conversion of backscatter into SSC does not require water samples and laboratory analysis anymore. The potential of the hydro-acoustic multi-frequency approach is illustrated with in-situ river measurements and laboratory experiments that cover a broad range of sediment concentrations and sediment characteristics.

How to cite: Höllrigl, J., Blanckaert, K., Hurther, D., Fromant, G., and Storck, F. R.: Suspended sediment measurements by hydro-acoustic multi-frequency echosounders, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18605, https://doi.org/10.5194/egusphere-egu25-18605, 2025.

Sediment transport plays a crucial role in shaping our natural and engineered landscapes, affecting everything from riverbanks to coastal regions and ecological habitats. It is key to effective disaster management, helping predict and mitigate the effects of floods, landslides, and coastal erosion. However, modeling how sediment moves through water and landscapes remains a complex challenge. This complexity is due to the unpredictable nature of turbulent flows and sediment movement, compounded by issues such as natural variability, lack of sufficient data for accurate model testing, and high computational demand.

This research introduces an innovative approach by integrating Lagrangian turbulent velocity theory into sediment transport models. By developing a new model that utilizes differentiable stochastic processes, this study aims to enhance our ability to predict and understand how particles behave in turbulent flows. This advanced modeling technique addresses key challenges like the unpredictability, intermittent behavior, and memory effects associated with particle movement in turbulent conditions. Ultimately, this research seeks to refine our understanding of sediment dynamics, pushing the boundaries of existing models and providing more reliable tools for environmental management.

How to cite: Tsai, C.: Lagrangian Stochastic Sediment Dynamics in Turbulent Flows, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19574, https://doi.org/10.5194/egusphere-egu25-19574, 2025.

We tested whether public high-resolution airborne LiDAR data could be suitable for structural geology applications by comparing fracture orientation measurements on Virtual Outcrop Models (VOMs) to field measurements from the same outcrops. We found that the fundamental requirement for taking full advantage of such data is good bedrock exposure, which is also dependent on lithology. Whenever this requirement is satisfied, VOM measurements are comparable to field measurements. VOMs can help considerably in both reducing the time it takes to collect measurements, and in expanding the area in which measurements can be collected without adding significantly to the time budget. They are also especially useful in remote regions and at high elevations, where access is more difficult and yet good exposures are more likely to be found, and they should always be used when planning field work. At present  the main limitations, apart from LiDAR coverage not yet existing in places, are due to the hardware and software capabilities needed to create and especially to analyze VOMs. 

How to cite: Carena, S. and Friedrich, A.: Mapping fractures in 3D from airborne LiDAR: comparison with field mapping, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2144, https://doi.org/10.5194/egusphere-egu25-2144, 2025.

The stability of rock masses is crucial for the safety of hydraulic engineering, as the integrity of the rock mass directly influences the stability of structures such as dams, reservoirs, and tunnels. Accurate extraction and orientation of rock mass discontinuities plays a key role in stability analysis, providing essential geometric data for assessing rock mass behavior. However, traditional manual measurement methods used to extract these orientations are not only time-consuming and labor-intensive but also fraught with safety risks, especially when working on large and steep slopes. These limitations hinder the efficiency and accuracy of rock mass stability assessments.

To address these challenges, this paper proposes a novel approach for acquiring 3D rock mass scenes using unmanned aerial vehicles (UAVs), coupled with oblique photogrammetry technology for 3D scene reconstruction. With UAVs equipped with high-resolution cameras to capture image sequences from various angles, the Structure from Motion (SfM) algorithm is then applied to reconstruct the 3D scene. This method allows for the generation of high-precision point cloud data through geometric uniform sampling, ensuring accurate representation of rock mass. Once the 3D scene is reconstructed, local geometric features (including surface curvature, planarity, scattering, and verticality) are calculated based on neighborhood search. Combined with RGB texture information, machine learning method is employed to analyze the importance of these features, and further identify and differentiate rock mass features from vegetation and outliers within the large-scale slope scene, followed by a region-growing and merging algorithm for the segmentation of rock mass patches. For each individual patch, a local planar coordinate system is established to generate a grayscale image, which is then used for edge detection to identify structural boundaries. Following this, line extraction is carried out using an energy-optimization-based graph cut algorithm, and the closed contours of the structural patches are delineated through vectorization, ensuring an accurate and detailed mapping of the rock mass structure.

The effectiveness of the proposed method was validated through experiments conducted on a large-scale rock mass slope scene. The results demonstrate that the method can accurately extract the rock mass structural regions, identify the fracture network, and provide crucial geometric features, such as dip, strike, and trace information for each structural plane. The extracted features significantly contribute to evaluating the structural integrity and stability of large-scale slopes, offering a more efficient, accurate, and safer alternative to traditional manual measurement methods. Moreover, this method can be applied to a wide range of geological environments, providing a valuable tool for real-time monitoring and assessment in engineering projects.

How to cite: Han, X., Zhai, R., Huang, Y., and Ding, B.: Extraction and Orientation Analysis of Rock Mass Discontinuities Using UAV-Assisted Photogrammetry, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2736, https://doi.org/10.5194/egusphere-egu25-2736, 2025.

Well-aligned point cloud time series data generated with Unmanned Aerial Vehicles (UAVs) can be a significant asset to geoscientists.
Practitioners benefit from multi-temporal point clouds with high comparative accuracy, e.g. to evaluate landscape changes after landslides and quantify mass wasting.
Two approaches are usually applied to achieve the accurate alignment of point clouds: indirect and direct georeferencing.
Indirect georeferencing uses well distributed Ground Control Points (GCPs) in the study area.
While this method significantly enhances the precision and accuracy of time series point clouds, the placement and measurement of GCPs are time-intensive and may even be impossible in difficult terrain.
Direct georeferencing depends on highly precise and accurate location information embedded in images, which is often viable only with expensive real-time kinematic (RTK) positioning equipment or post-processed kinematic (PPK) services.
Beyond the extra cost, this approach faces the same challenges as indirect georeferencing, particularly in the placement of equipment and scalability for large areas.

Recent research has introduced an alternative method called Co-Alignment, which enables the alignment of point clouds with high local precision without GCPs and RTK data. Moreover, when GCPs or RTK are used, co-alignment can further enhance accuracy of the point cloud alignment.
This method aligns multiple point clouds with good local precision without requiring GCPs or RTK equipment, though it lacks global accuracy.
The workflow uses common, unchanged features in the study area, such as anthropogenic structures or boulders, to establish spatial references across multiple epochs using computer vision algorithms.

We developed FACA - Fully Automated Co-Alignment to implement the Co-Alignment workflow.
With FACA, we aim to offer easy access to a scalable point cloud alignment method.
FACA is automatable from the command line and user-friendly through a custom graphical user interface, making it adaptable to common point cloud generation workflows.
Released as open-source software under the GNU General Public License v3, FACA is freely accessible and modifiable to meet diverse user requirements.
By integrating with Agisoft Metashape Professional, FACA leverages advanced photogrammetric features to enhance performance and output quality.
We present the FACA workflow, emphasizing its ease of use, scalability, performance, supported by results from data acquired at Germany's Baltic Sea coast and in Svalbard.

Furthermore, we discuss the potential for custom software solutions to further improve and expand the workflow’s capabilities.

How to cite: Schüßler, N., Torizin, J., Gunkel, C., Fuchs, M., Schütze, K., Tiepolt, L., and Kuhn, D.: An Introduction to Fully Automated Co-Alignment - FACA, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4331, https://doi.org/10.5194/egusphere-egu25-4331, 2025.

Historical imagery captured from aeroplanes since the early 1900s and from spy satellites from the 1960s onwards have long been used in natural sciences for military, civil, and research purposes. These images have the unequalled potential for documenting and quantifying past environmental changes caused by natural and anthropogenic factors. Especially when acquired in stereo mode, these images enable the generation of point clouds and digital elevation models (DEMs), allowing us to quantify surface elevation changes over the past century.

Recent advancements in digital photogrammetry and the increasing availability of historical photographs as digitised/scanned images have heightened the interest in these data for reconstructing long-term surface evolution from local to regional scale. However, despite the large archive of historical images, their full potential is not yet widely exploited. Key challenges include accessibility, lack of metadata, image degradation, limited resolution and accuracy and lack of standardised workflows for generating DEMs and orthophotos.

We reviewed 198 journal articles published between 2001 and 2023 that processed historical aerial and spy satellite imagery. Our review spans methodological advancements in photogrammetric reconstruction and applied research analysing past 2D and 3D environmental changes across geoscience fields, such as geomorphology, cryosphere, volcanology, forestry, etc. We provide a comprehensive overview of these studies, summarise the image archives, applications, and products, and compare the methods used to process historical aerial and spy satellite imagery. Furthermore, we highlight emerging workflows and offer recommendations for image processing and accuracy assessment for future research and applications.

How to cite: Piermattei, L., McNabb, R., Elias, M., Ressl, C., Dehecq, A., Girod, L., Dewez, T., and Eltner, A.: Unlocking the potential of historical aerial and spy satellite stereo-imagery in geosciences: access, processing, and applications, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5168, https://doi.org/10.5194/egusphere-egu25-5168, 2025.

The project's goal is to create a software tool for detecting and predicting a higher form of (rill) erosion on agricultural land. The planned tool's innovative potential is the use of neural networks on the joint remote sensing and erosion-hydrological modelling data. Morphological parameters and erosion-hydrological causal event response thus enhance common inputs for the neural network-driven semantic segmentation.

By combining morphological parameters, event-based hydrological responses, and a calculated critical water layer thickness (h_crit) from physical SMODERP model - the threshold at which rill erosion begins - the tool enhances the precision of high-risk area delineation, supporting smart agriculture and climate adaptation.

The project utilizes a unique dataset of manually digitized erosion rills from over 20 years of aerial orthophotos, enabling comprehensive training of neural networks. Multi-resolution data, including satellite imagery, aerial orthophotos, and UAV images, are combined to identify and refine morphological properties critical for rill erosion detection. Several types of neural networks were tested, notably FCN, U-Net, SegNet, DeepLabv3+, to evaluate their effectiveness in handling diverse input data and optimizing predictive accuracy. Automated workflows for dataset expansion and retraining ensure adaptability to new data.

Validation of the model will be performed using the original dataset of manually digitized erosion rills as a benchmark for accuracy. By comparing the predicted rill locations with this dataset, the model’s performance can be rigorously evaluated and adjusted. Real-time erosion event mapping, supported by the Agricultural Land Erosion Monitoring system, will complement this process by incorporating contemporary data to further enhance model reliability. This innovative tool addresses gaps in existing methods by combining predictive capabilities with detailed spatial data, improving erosion detection accuracy for sustainable land management under changing climatic conditions.

The research is funded by the Technological Agency of the Czech Republic research project (TQ03000408)- Detection of Increased Erosion Damage Using Neural Networks on a Combination of Remote Sensing Imagery and Erosion-Hydrological Modeling and an internal student CTU grant (SGS23/155/OHK1/3T/11).

How to cite: Tejkl, A., Kavka, P., Pesek, O., and Landa, M.: Detection of Increased Erosion Damage Using Neural Networks on a Combination of Remote Sensing Imagery and Erosion-Hydrological Modeling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5875, https://doi.org/10.5194/egusphere-egu25-5875, 2025.

The digitisation of historical aerial photograph archives offers a unique opportunity to analyse long-term environmental changes. One such valuable resource is the archive of 1935-1941 aerial photographs of Ethiopia, one of the largest and oldest collections in Africa, comprising 34,000 images. While a portion of these images has been localized, many remain without known coordinates. To address this, we developed a computer vision approach that combines scale invariant feature transform (SIFT) keypoint matching and nearest-neighbour search, achieving 99% accuracy and 80% recall in matching images. This method increased the localization rate from 40% to approximately 70%, though manual verification and coordinate determination remain necessary. A proof-of-concept further demonstrated the potential of utilizing depth information to localize photographs: by leveraging the spatial proximity of images within the quite erratic flight lines, we significantly reduced the search area. Additionally, we show that 3D scene reconstruction from consecutive images, matched to a digital elevation model using the ICP algorithm, is feasible.

We demonstrate the potential of historical aerial archives for studying long-term environmental change through a case study on river geomorphology. At 70 locations where aerial photographs intersect major unconfined rivers, we analysed key hydrogeomorphological variables to assess river dynamics. By comparing river morphology in 1935-1941 with that on the most recent Google Earth imagery, our results reveal significant morphological changes, including channel widening, gullying, bank erosion, and in-stream sediment accumulation. These findings highlight how a detailed understanding of local river dynamics, derived from historical and modern imagery, can enhance the broader understanding of environmental changes and their impacts on catchment behaviour.

Key words: Aerial Photographs, Environmental Change, Hydrogeomorphology, Environmental Change, River

How to cite: De Baets, M., Lamote, L., Sterckx, J., Annys, S., Nyssen, J., Luong, H., Gebreyohannes, T., and Frankl, A.: The use of computer vision to relocate historical aerial photographs that enhance the understanding of hydrogeomophic changes in Ethiopia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6611, https://doi.org/10.5194/egusphere-egu25-6611, 2025.

Climate change is resulting in rapidly increasing temperatures in the European Alps, rising twice as fast compared to the global average, and leading to unprecedented glacier retreat. Deglaciating alpine landscapes are considered extremely dynamic, evolving rapidly over space and time. The use of DEMs (Digital Elevation Models) of Difference (DoDs) to study changes occurring in these environments has significantly increased in the last years and has been used for a wide range of disciplines. This approach builds on the growing availability of datasets (e.g. historical imagery), accessibility of drones and their sensors (e.g. LiDAR) and facilitated use of digital photogrammetry through commercial and open-source Structure-from-Motion software. However, DoDs of deglaciating landscapes tend to disregard the diversity and complexity of processes in these environments. 

In this research, DEMs were obtained using aerial archival photogrammetry (1977) for the Turtmann basin, a rapidly deglaciating Alpine valley in the Canton of Valais (southwestern Switzerland. A 2021 DEM was used as a reference to create a DoD of the basin (28km²), in order to determine net sediment erosion and deposition during this 44-year time period. 

Most changes identified in the DoD could not be attributed to sediment displacement, but rather to various ecological (e.g. tree growth), glacial (e.g. glacier ice melt) and periglacial (e.g. rock glacier and buried ice melt) processes, as well as error in the photogrammetry. The latter is amplified by the inherently steep topography of alpine basins, which means that small georeferencing errors can cause significant apparent vertical change. A series of post-processing steps were required to obtain precise sediment volumes from the DoD. 

DoDs are extremely valuable for assessing changes in rapidly deglaciating environments. However, challenges exist when applying them to such topographically complex and dynamic landscapes. These challenges must be identified and thoroughly dealt with through DoD post-processing in order to exploit DoDs to their full potential and obtain precise volumes of change. The specific post-processing steps will depend on (1) the research objective, which determines the desired precision as compared to the limits of detection, and (2) the spatial and temporal scales of the DoD, which influence the detectability of changes. In this research, the large temporal (decades) and spatial (basin-wide) scales exposed the challenges and opportunities of using DoDs in rapidly deglaciating environments. The workflow developed to overcome these challenges can be applied to other alpine basins for more precise change detection and thus allow for a better quantitative understanding of processes in deglaciating environments. 

How to cite: Repnik, L., Breillad, A., Giovanardi, A., Comiti, F., Gianini, M., Argentin, A.-L., Pitscheider, F., and Lane, S. N.: Historical photogrammetry for DoDs in deglaciating environments: challenges and opportunities, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6774, https://doi.org/10.5194/egusphere-egu25-6774, 2025.

Different people perceive landscapes in various ways depending on their cultural and social background as well as their own values. However, characteristics inherent in the landscapes also have an impact on their perceived beauty. Accordingly, it remains unclear to what extent personal assessments and landscape properties influence how much people appreciate landscapes. In this study, we had 50 test subjects evaluate alpine landscapes represented by 30 historic and recent rendered pictures each. Since the recent pictures should display the exact same part of the landscape as the historic ones, digital elevation models (DEMs) and orthophotos were used to render the current scene in the same greyscale range as in the historic photographs. Additionally, DEMs and landcover maps for the captured images were analysed. These results were used to explain the test subjects’ values of the appreciation of and desire to travel to the landscapes using linear mixed models.

The key finding is that perceived landscape attractiveness depends more on the people assessing the landscapes than the landscape characteristics themselves. The number of distance zones (surrounding, near, middle and far zone) present in the viewshed has a significant impact on the appreciation of the landscape. The maximum slope affects the desire to travel to the landscapes, and the relief energy, the viewshed size and the ratio of the recently glaciated area influence both the appreciation of and the desire to travel to the landscape. Furthermore, the historic photographs are perceived as more beautiful than the recent rendered ones. Taking into account the ratio of the glaciated area, this difference is even more pronounced for the desire to travel to the landscape. The bigger the difference in the glaciated area between the historic and recent image is – hence the more glacier has melted – the more the test subjects desire to travel to the scene shown in the historic picture than in the recent one.

How to cite: Koschmieder, M., Pfeuffer, C., Mikolka-Flöry, S., and Heckmann, T.: Landscape attractiveness – It depends on the observer, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11270, https://doi.org/10.5194/egusphere-egu25-11270, 2025.

Raw terrain data acquired by sensing techniques such as SfM or LiDAR typically contain non-terrain components that require filtering, such as vegetation occlusion and other non-terrain features. While filtering helps remove non-terrain data, it can introduce discontinuities and local voids in the dataset. These data gaps can affect both the completeness of the terrain representation and subsequent analysis tasks. Therefore, it is crucial to develop effective terrain data completion methods for reliable terrain analysis.

Traditional terrain data completion methods, such as interpolation-based algorithms and Poisson surface reconstruction, typically model and optimize data continuity from a mathematical perspective. Although these methods address local voids to some extent, they generally fail to exploit terrain features and semantic information, limiting their effectiveness in completing complex terrain scenarios.

To address these issues, we propose a deep learning-based framework for terrain data completion. Our methodology explores different neural network designs with supervised and unsupervised learning, incorporating geomorphological constraints to improve terrain feature representation and semantic understanding. The framework leverages the representational capabilities of deep learning to improve the robustness of terrain data completion, contributing to a more consistent and reliable basis for subsequent terrain analysis and applications.

How to cite: Lu, T. and Jaboyedoff, M.: Deep Learning-based Terrain Data Completion with Geomorphological Constraints, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12156, https://doi.org/10.5194/egusphere-egu25-12156, 2025.

The assemblage of multiple sensors on Unmanned Aerial Systems (UAS) to collect high resolution geospatial data represents one of the most significant advances in remote sensing, including oceanographic applications. Coastal inundation of pelagic Sargassum has been thoroughly documented as a natural hazard that jeopardizes the ecological integrity of coastal ecosystems, unbalancing several livelihoods and local economies. Sargassum patches (rafts) are drifted offshore by surface ocean currents, with distinct drivers at different geographic and time scales. UAVs have revolutionized the immediate local remote sensing of Sargassum as they can identify rafts that are expected to reach the coast in terms of hours, becoming a strategic tool for rapidly management actions, bridging the on-site actions with high and medium resolution satellite detections. To obtain primary data on the extent, frequency, and magnitude of floating and beached Sargassum in the Mexican Caribbean, a rapid assessment protocol based on aerial photogrammetric techniques was implemented in the Yucatan Peninsula. We documented the arrival of sargassum rafts in the nearshore environment used to perform statistical comparisons with other remote sensing products. High resolution orthomosaics, DSMs, and 3D reality models were created to document the extent and quantity of beached Sargassum and the contiguous “brown tide” areas. Floating sargassum rafts were also identified in real time using long-range telemetry UAVs between 2 and 20 km offshore, that were consistent with field-based observations. Ocean circulation model outputs are also presented, which demonstrate that including UAV-mounted multi-sensors data acquisition is fundamental towards a comprehensive description and monitoring of the Sargassum coastal dynamics. These results strongly suggest that UAV-derived cartographic products represent an efficient tool for Sargassum-management actions, downscaling satellite detections and linking them with local observations, a strategy that needs to keep addressing as the future research agenda in Operational oceanography.

How to cite: Gudino-Elizondo, N., Cuevas, E., Uribe-Martinez, A., Garcia-Nava, H., Flores-Vidal, X., and Avendaño-Gastelum, O.: Multiple airborne sensors to monitor rafts and beached Sargassum in the Mexican Caribbean: Documenting different UAVs applications for management actions., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15301, https://doi.org/10.5194/egusphere-egu25-15301, 2025.

Alpine alluvial fans are important storages in the alpine sediment cascade. It is to be expected that climate change and the resulting changes in precipitation will have a massive impact on the dynamics of alpine alluvial fans. In order to differentiate between short-term and long-term dynamics, we compile a dataset quantifying sediment redistribution of a small mountain river and its alluvial fan on centennial, decadal and sub-annual scales. Our dataset comprises historical topographic maps from 1826 to 1912, 25 sets of historical aerial images collected between 1945 and 2024, and 17 high-resolution UAV-campaigns collected between September 2018 and October 2024. We identify the spatial changes in the sediment body, quantify the sediment redistribution and relate both to precipitation.

On centennial timescales, our data show a shift from presumably low geomorphic activity that persisted for at least 100 years (1820s-1930s) in the eastern sector of the fan, to high geomorphic activity with rapid channel migration across the central fan within the past 60 years. The onset of intense geomorphic activity may be contemporaneous to the increase in debris flow activity at nearby lake Plansee in the 1920s (Kiefer, Oswald et al., 2021). Decadal changes to the active area are largely explained by median precipitation (r² = 0.66, p < 0.002) measured at a weather station c. 10 km east. Since the 1960s, incision at the apex and deposition at the toe of the fan can be observed. Sub-annual change detections show that for most epochs, erosion and deposition balance out within the uncertainty margin and the main channel gradually shifts its position by bank erosion and gravel bar construction. However, following an extreme deposition event between August and September 2019 with a net deposition of 8000 ± 3500 m³, the course of the main channel abruptly shifted. Our preliminary results show that while historical maps and aerial images are useful to reconstruct long-term trends, repeat topographic surveys with a close temporal spacing are needed to understand the processes behind these trends.

Kewords: alpine alluvial fan, sediment redistribution, geomorphic change detection, multiscale investigation

Kiefer, C., Oswald, P. Moernaut, J., Fabbri, S.C., Mayr, C., Strasser, M. & Krautblatter, M. (2021): A 4000-year debris flow record based on amphibious investigations of fan delta activity in Plansee (Austria, Eastern Alps). – Earth Surface Dynamics, 9: 1481–1503. DOI: 10.5194/esurf-9-1481-2021

How to cite: Gewalt, P., Wagner, T. C., and Krautblatter, M.: Constraining centennial to sub-annual sediment dynamics on alpine alluvial fans – first insights from the Friedergries (Germany), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15820, https://doi.org/10.5194/egusphere-egu25-15820, 2025.

During the last decades the high Arctic has undergone substantial changes as a result of global warming and arctic amplification. Melt seasons are expanding rapidly, and landscape and ecosystems are shifting into new states. To quantify these changes from the historical baseline requires datasets on pre-warming states, which can be extremely rare in the high Arctic. Prior to the satellite era, starting in the 1990s, a commonly used data source for baselines in geosciences is aerial photographs, which if one is lucky can reach back to the 1930s. These aerial images are most often recorded at high elevation and perhaps also obliquely which results in spatial resolutions of 2-10 meters, limiting the level of detail that can be resolved on the ground.  

With this presentation we reveal a new exciting dataset of aerial images from East Greenland recorded in the 1950s and ‘60s. Contrary to other aerial campaigns, these images were recorded at very low elevation in order to conduct geological mapping, ultimately yielding spatial resolutions surpassing those of the newest high resolution satellites.

The images were recorded by geologist John Haller during the Lauge Koch expeditions to central East Greenland in the 1950s and 1960s, and comprise a dataset of c. 3600 high resolution oblique images recorded at low elevation from plane and helicopter. The images are recorded in stereo, which allows us to recreate the terrain surface in 3D and construct orthorectified imagery that allows a direct comparison with modern satellite images, for use in all aspects of landscape- and ecosystem evolution.

How to cite: Bjork, A., Deichmann, A., and Socher, T.: A new high resolution historical aerial image dataset from East Greenland, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16381, https://doi.org/10.5194/egusphere-egu25-16381, 2025.

Trend determination for earth surface processes requires long and continuous and certain measurements, but long-term records of landscape change are often limited in temporal and spatial extent. Scanned historical aerial imagery serve as a valuable resource to derive data products like digital elevation models (DEMs) to document the historical state of the Earth's surface and to calculate trends for different processes e.g. glacier dynamics.

Classic Structure-from-Motion (SfM) photogrammetry workflows have demonstrated the capability to automatically generate DEMs and orthoimage mosaics from such historical images, as highlighted in a few studies. These workflows typically consist of the following steps: (a) pre-processing, (b) tie-point extraction, (c) matching, (d) bundle adjustment, (e) dense reconstruction, (f) co-registration, and (g) orthoimage mosaic generation. However, classic methods struggle with the challenges historical imagery coming with. For example: inconsistent image quality, limited metadata documentation, image distortions and distinct viewpoint geometries.

Recently, advances in robotics and computer vision have introduced learned models for tasks such as tie-point identification, matching, dense reconstruction as well as part of the co-registration stage (e.g. SuperPoint, ALIKE, SuperGlue, LoFTR and more). These networks have shown promising results in different stereo-matching scenarios by outperforming classic SfM methods. However, since they were primarily developed for modern robotics and computer vision tasks, their performance on scanned historical aerial imagery remains uncertain. As historical imagery exhibits the properties described above, these networks were not optimised with them during training.

We boost existing pipelines in tie-point extraction and matching with these models and compare the quality of resulting DEMs from different model combinations together. We also highlight issues encountered when applying these learned models to historical aerial imagery and proposes solutions to address them. We demonstrate our findings using scanned historical images from the Southern Patagonian Ice Field (Chile) recorded in 1980, particularly for the Grey & Dickson Glacier area, as well the south-west flank of Cordon Mariano Moreno Mountain and adjacent fjords. These two sites providing different acquisition geometries and overlaps. The results evaluate the average RMS reprojection error following the bundle adjustment, to determine the quality of different extractors and matchers as well as the median distance between closest points to evaluate the co-registration.

How to cite: Kugler, L., Ioli, F., Wegner, J. D., Dussaillant, I., Rada, C., and Piermattei, L.: Advances in Historical Aerial Image Analysis: Boosting SfM Pipelines with Learned Models, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17688, https://doi.org/10.5194/egusphere-egu25-17688, 2025.

Along many coastlines worldwide, a variety of direct and indirect anthropogenic influences are influencing natural processes of coastal erosion and deposition.  Both traditional change reconstruction and monitoring techniques (e.g. repeat surveys) and increasingly sophisticated approaches (e.g. photogrammetry, LiDAR, drone imagery) require specialist knowledge and equipment, can be time consuming to apply, and may be restricted to assessing relatively recent changes over short timeframes (e.g. typically years to a few decades).  Here, we evaluate the potential for archival visual sources - maps, paintings, geological sketches, and historical photographs – to help document changes in the coastal environment of Ceredigion County, west Wales, over the past 100-150 years.  Two extant sites of geoscientist interest, both located within 20 km of Aberystwyth, were investigated: Harp Rock (Craig y Delyn), which represents the westward-dipping limb of a synclinal fold, and Monk’s Cave (Twll Twrw), which has essentially now developed into a coastal arch.  Egg Rock (Tŵr Gweno), a coastal stack which was previously located near to Monk’s Cave but has since disappeared, was also investigated.  All three sites were well-known tourist attractions in the late 1800s and early 1900s, and various maps, paintings, sketches and photographs help to provide both qualitative and quantifiable insights into the nature of coastal change, including the sequencing, rates, and timing of key changes, as well as volumes of mass loss.  For example, Harp Rock is retreating landward as sandstone strata of ~37 cm thickness are removed by wave action and mass movement; for every 1 m² of stratal loss, a mass of 858.4 kg is removed.  For Monk’s Cave, the average vertical erosion rate of the cave entrance is estimated to ~0.65 cm/yr over a timespan of 139 years.  Based on the last known photograph of Egg Rock (early 1900s), the total mass loss is approximated to be 197.70 t.  Collectively, the findings from these three sites provide insights into rates of Holocene shore platform development along this dynamic coastline.

Wider use of archival visual sources clearly has potential for complementing more technically sophisticated short-term change reconstruction and monitoring approaches.  Key challenges include sourcing well-dated, high-quality archival visual sources to enable establishment of robust timelines of change and the generation of quantitative data, and safely accessing potentially hazardous locations to enable new paintings, sketches, or photography.  If these challenges are surmounted, opportunities include enhanced potential for: i) providing quantified landscape change case studies for inclusion in school/university geoscience syllabi; ii) demonstrating the relevance of geoscience for local/regional natural and cultural heritage; and iii) enhancing public engagement with coastal geoscience (e.g. through citizen science projects or science-art collaborations).

How to cite: Goode, C. and Tooth, S.: Can archival visual sources be used to quantify coastal change?: insights from the dynamic coastline of Ceredigion, west Wales, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18399, https://doi.org/10.5194/egusphere-egu25-18399, 2025.

Cosmogenic isotope dating of rock samples taken from shore platforms is the only dating method for reconstructing the long-term evolution (centuries to millennia) of fully erosional rock coasts. Two techniques can be used: the first is based on the collection of samples on the platform and the distribution of their cosmogenic isotope concentrations over a transect perpendicular to the shoreline (e.g. Regard et al., 2012; Hurst et al., 2016; Swirad et al., 2020); the second, which is limited to low rates of recession, is implemented by measuring cosmogenic isotope concentrations in the colluvium at the foot of the cliff (Bossis et al., 2024). Here we focus on the first technique which involves fitting the distribution of observed concentrations to a model. This model allows the cliff retreat rate to be constant or variable over the Holocene, and shore platform either to erode in concert with the cliff retreat (steady state model) or to widen through time. The simple inversion model is as widely usable as possible and allows a quick, easy, robust and standardised calculation of exposure ages based on information such as cosmogenic isotope concentrations, present topography and relative sea level change.

References

Bossis, R., Regard, V., Carretier, S., and Choy, S., 2024, Evidence of slow millennial cliff retreat rates using cosmogenic nuclides in coastal colluvium: EGUsphere, p. 1–15, doi:10.5194/egusphere-2023-3020.

Hurst, M.D., Rood, D.H., Ellis, M.A., Anderson, R.S., and Dornbusch, U., 2016, Recent acceleration in coastal cliff retreat rates on the south coast of Great Britain: Proceedings of the National Academy of Sciences, v. 113, p. 13336–13341, doi:10.1073/pnas.1613044113.

Regard, V., Dewez, T., Bourlès, D.L., Anderson, R.S., Duperret, A., Costa, S., Leanni, L., Lasseur, E., Pedoja, K., and Maillet, G.M., 2012, Late Holocene seacliff retreat recorded by 10Be profiles across a coastal platform: Theory and example from the English Channel: Quaternary Geochronology, v. 11, p. 87–97, doi:10.1016/j.quageo.2012.02.027.

Swirad, Z.M., Rosser, N.J., Brain, M.J., Rood, D.H., Hurst, M.D., Wilcken, K.M., and Barlow, J., 2020, Cosmogenic exposure dating reveals limited long-term variability in erosion of a rocky coastline: Nature Communications, v. 11, p. 3804, doi:10.1038/s41467-020-17611-9.

How to cite: Regard, V., Swirad, Z., Chokrafi, I., Carretier, S., and Hurst, M.: Estimating long-term coastal cliff retreat using cosmogenic nuclides: Development of a user-friendly inversion tool, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2817, https://doi.org/10.5194/egusphere-egu25-2817, 2025.

Hillslope processes play a significant role in shaping catchment-scale erosional dynamics. These processes include mechanisms from granular creep to large-scale morphological changes influenced by tectonic and climatic forces over both short and long timescales. Despite advancements in quantification methods, a granular-level understanding of these processes remains unclear. Moreover, a systematic approach to link the variability of hillslope processes across different temporal scales is still lacking. Thus, integrating single-grain luminescence analysis with cosmogenic nuclide-derived erosion rates from modern fluvial deposits can bridge these gaps, offering deeper insights into hillslope processes.

Single-grain luminescence provides detailed grain-specific insights into sediment production, erosion, transport, and deposition processes over millennial timescales. In contrast, cosmogenic nuclide-based methods analyze the long-term mean signal from a large grain population. Thus, comparing single-grain luminescence dose distribution with cosmogenic ¹⁰Be-derived catchment-wide erosion rates in fluvial sediments could help identify various hillslope processes with higher analytical resolution over varying timescales. We hypothesized that grains transported by soil creep will be sufficiently bleached (zero or negligible remaining luminescence signal). In contrast, grains transported via landslides will predominantly exhibit incomplete or no bleaching (considerable remaining luminescence signal or saturated with luminescence signal).

To test this hypothesis, we measured the proportion of bleached versus non-bleached grains in modern fluvial deposits sourced from 11 catchments falling in a climatic gradient and also with contrasting morphometric properties in the Southern Central Andes (Chile) using post-IR IRSL signal of K-feldspar. Contrary to expectations, we observed a weak negative correlation between the proportion of bleached grains and erosion rates, suggesting complex transport dynamics and variable opportunities for bleaching across catchments. Additionally, a weak positive correlation between non-bleached grains and erosion rates suggests complex sediment storage and reworking within the system, and an absence of large morphologic changes, such as deep-seated landslides.

Therefore, comparing the luminescence signals of hundreds of grains with catchment-wide erosion rates across various temporal scales provides valuable complementary insights into (a) the mechanisms driving hillslope erosion, (b) their influence on catchment-wide erosion rate estimates, and (c) the complex sediment dynamics within catchments.

How to cite: Biswas, A., Riedesel, S., Karman-Besson, L., Guyez, A., A. Binnie, S., Bonnet, S., and Reimann, T.: Linking single-grain luminescence and erosion rates to understand erosional and sediment dynamics in the Southern Central Andes, Chile, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2881, https://doi.org/10.5194/egusphere-egu25-2881, 2025.

The origin of inselbergs is classically linked to long-term episodic exposure, alternating between the deepening of the weathering mantle and the regolith stripping driven by differential erosion. However, a better understanding of denudation patterns and exposures ages in granite landscapes is hindered by key gaps arising with this assumption: i) the absence of sedimentary markers or their dating; ii) the scarcity of quantified denudation rates to reconcile with classical models of evolution in cratonic zones. To address these gaps, in-situ produced ¹⁰Be and ²⁶Al in river-borne sediments, bedrocks, and sedimentary deposits can be compared and analyzed to quantify the role played by differential erosion in the evolution of granitic inselbergs and to unravel complex exposure histories. Previous studies quantifying erosion in granitic landscapes have focused on small inselberg groups or isolated high inselbergs, comparing rock surfaces without integrating sedimentary covers or basin-averaged denudation, thereby limiting regional-scale understanding. In this study, we paired ¹⁰Be and ²⁶Al in quartz from sands and rocks collected across watersheds, colluvial-eluvial sediments, and inselbergs. Denudation rates were combined to reconstruct the history of inselbergs in a tropical semiarid setting.

Using this approach, we selected the Quixadá/Quixeramobim Complex (NE Brazil), a globally significant inselberg field with 561 units, renowned for its diverse granite landforms in cratonic and semiarid areas. These landforms rise 1-410 m above the Surface Sertaneja (160-240 m). Within the plutons, the erosion surface is ~20 m lower than in adjacent regions, where metamorphic rocks and colluvial-eluvial covers are found.

Our results show that colluvial-eluvial covers exhibit higher cosmogenic nuclide concentrations than bedrocks, with values at least twice as high as those in watersheds. Conversely, catchments experience faster erosion than bedrocks. All bedrocks and 60% of the catchments are plotted within the steady-state erosion island, whereas Cenozoic covers display low ²⁶Al/¹⁰Be ratios. Average exposure ages suggest a Pleistocene age (1.0-1.4 Ma) for sedimentary covers. This reflects a general denudation pattern where inselbergs and sedimentary surfaces are preserved while the regional erosion surface is progressively stripped.

Assuming no erosion for sedimentary covers and continuous denudation, the differential denudation obtained between inselberg top and basin-averaged rates indicates that ~20 Ma is required to grow a 175 m-high inselberg, and ~50 Ma for a 400 m-high inselberg. These results highlight the utility of cosmogenic techniques in measuring denudation rates and improving the understanding of processes that govern origin and development of inselbergs.

How to cite: da Silva Barbosa, A. B., Siame, L., Maia, R. P., Leanni, L., Bastos, F. D. H., and Team, A.: Erosion and development of granitic inselbergs in cratonic zones: insights from the Quixadá/Quixeramobim Complex, NE Brazil, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5239, https://doi.org/10.5194/egusphere-egu25-5239, 2025.

Bioturbation has a large impact of carbon and nutrient cycling in soils and therefore plays a key role in current-day soil functioning and long-term soil evolution. Despite its importance, fundamental knowledge on the mechanisms and rates of different soil bioturbation processes is limited, which prohibits accurate modelling of these processes.

Luminescence, a light-sensitive mineral property of the two most abundant minerals at the Earth surface (quartz and feldspar), is a valuable tracer for deriving rates of long-term bioturbation. It measures the last exposure of siliclastic particles to daylight and can therefore act as a proxy of subsurface residence times. However, these luminescence tracers do not account for previous resurfacing of grains and subsurface transport without bleaching, and therefore only represent the net replacement of the particles. This leads to an underestimation of bioturbation rates when derived from luminescence tracers only.

In this presentation, we introduce the new simulation model named Mixed Signals, which simulates two main bioturbation processes and their impacts on luminescence tracers: mounding (advective transport to the surface) and subsurface mixing (diffusive transport within the subsurface). We applied the model to two published luminescence datasets, each from settings dominated by organisms with distinct burrowing behavior: termites and anecic earthworms. We calibrated the model using different statistics derived from the experimental and simulated luminescence age distributions to derive bioturbation rates and mixing characteristics for the two datasets.

The model produced bioturbation rates that are orders of magnitude larger than the rates derived from the luminescence datasets alone, yet they are consistent with rates derived from observations. While some limitations remain, such as the need for a better experimental understanding of light penetration in soils for particle bleaching, our findings show the potential of the Mixed Signals model to extract accurate bioturbation rates from luminescence data. The model greatly enhances our understanding of bioturbation dynamics and improves the use of luminescence as a tracer for soil processes.

How to cite: van der Meij, M., Riedesel, S., and Reimann, T.: Mixed Signals: soil bioturbation rates from luminescence and numerical modelling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5643, https://doi.org/10.5194/egusphere-egu25-5643, 2025.

The Variscan basement units of the Bohemian Massif and other Variscan domains in Central Europe are thought to be less affected by Cenozoic tectonics. However, analyses using geomorphic indices and river profiles reveal spatial variations in the evolved topography in the Bavarian Forest, the southwestern segment of the Bohemian Massif. The geomorphic analyses suggest disequilibrium along drainage divides and in river profiles. It has been suggested that the topography in the southern parts of the Bohemian Massif has rejuvenated (Zebari et al., 2024). However, interpretations aimed at extracting tectonic signals from geomorphic analysis are inherently relative, and it is sometimes challenging to separate tectonic signals from climate signals or differential erodibility. To further quantify landscape dynamics in the Bavarian Forest, we estimated long-term watershed-averaged denudation rates from in-situ produced ¹⁰Be cosmogenic nuclide analysis of sand samples collected from outlets of 15 representative watersheds in the Bavarian Forest.

Our initial results indicate that watershed-averaged denudation rates in the Bavarian Forest range from 21.1 ± 2.4 to 40.5 ± 4.8 mm/kyr. These denudation rates represent a time period equivalent to the removal of approximately 60 cm of rocks, corresponding to about 15 kyr for the fastest-eroding watershed and about 28.5 kyr for the slowest one. There are spatial variations in the denudation rates, with the watersheds clustering into several distinct subregions. Overall, watersheds in the southeast, within or around the Ilz catchment, and those in the high-elevation areas of the Hinterer Bayerischer Wald, have relatively higher denudation rates than those in the central segment of the Vorderer Bayerischer Wald. Furthermore, notable differences are also found across the drainage divide between the Regen and Danube rivers in the adjacent watersheds, and these differences are consistent with the analysis of drainage divide dynamics using the χ (Chi) integral. Additionally, the calculated denudation rates also correlate with the topographic metrics of watershed and river profiles.

The same climatic conditions and minimal contrast in rock erodibility are expected for the adjacent watersheds in the Bavarian Forest; therefore, these denudation rates may represent a brief time window within a longer span of tectonic processes that shaped the relief there. Broad surface uplift of the Northern Alpine Foreland Basin and beyond, since prior to 6 Ma, and associated drainage network reorganization may have also affected the southern regions of the Bohemian Massif, resulting in the rejuvenation of topography in the Bavarian Forest, notably within its southeastern part. Thus, it is expected that the driving forces for the broad-scale recent surface uplift event(s), which affected the Bavarian Forest, also reactivated the major bounding faults.

References:

Zebari, M., Friedrich, A. M., Ludat, A. L., Kahle, B., Rieger, S. M., & Kübler, S. (2024). The role of late Cenozoic intraplate tectonic in shaping the topography of the Bavarian Forest, southwestern Bohemian Massif, Germany. Geologica Bavarica, 130: 35–55.

How to cite: Zebari, M., Wittmann, H., and Friedrich, A.: Late Pleistocene-Holocene denudation rates in the Bavarian Forest from in-situ produced 10Be cosmogenic nuclides , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5647, https://doi.org/10.5194/egusphere-egu25-5647, 2025.

Quantifying the magnitude of rapid changes in our past climate system is paramount to our awareness of the scale and impact of current and future climate change. While a number of proxies enable surface air temperature reconstructions, methodological limitations and preservation issues limit the spatial coverage and timeframe for which most of these can be sucessfully applied. As a result, for major changes in our climate system like the Pleistocene-Holocene transition including the rapid warming and environmenal adaptions following the Last Glacial Maximum (LGM), the lack of  terrestrial records leads to increased uncertainty in reconstructions of continental temperature.

Recently, low-temperature thermoluminescence (TL) signals of feldspar (i.e., 200–280 °C) have been shown to be sensitive to terrestrial temperature fluctuations over geological timescales and can thus inform on past surface temperature in terrestrial settings (Biswas et al., 2020). Using physical principles best known from trapped charge dating, the trapped charge population can be used to infer paleotemperatures in the form of temperature histories through inverse modelling. For this, other time resolved relative temperature records such as the Greenland ice sheet 𝛿¹⁸O-, speleothem-, or pollen records can be used as additional constraints.

Applying the TL paleothermometry approach, we present first reconstructions of LGM surface air temperatures at central European study sites. Additionally, we benchmark improvements of the method against samples from stable temperature crustal environments, namely the KTB and MIZ-1 boreholes located in Germany and Japan, respectively. Our ultimate objective is to combine these data with other northern hemisphere samples to improve our understanding of the Euro-African LGM continental surface air temperature.

References

Biswas, R.H., Herman, F., King, G.E., Lehmann, B., Singhvi, A.K., 2020. Surface paleothermometry using low-temperature thermoluminescence of feldspar. Clim. Past 16, 2075-2093.

How to cite: Oehler, S., Schmidt, C., Niyonzima, P., King, G. E., Biswas, R. H., and Herman, F.: Thermoluminescence paleothermometry enables LGM surface temperature reconstruction at central European study sites, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6215, https://doi.org/10.5194/egusphere-egu25-6215, 2025.

At the end of the last glaciation, landscapes have undergone profound changes, with increased temperature and modification of precipitation regimes changing the way sediments are produced and transported at the Earth's surface. Records of past denudation rates are essential for understanding how landscapes responded to this transition, and to assess their sensitivity to local environmental, climatic and geomorphic conditions.  Terrestrial Cosmogenic Nuclides (TCN) can be used in different ways to constrain paleo-denudation rates over 10s ka timescales, but few datasets exist that display strong signals regarding the dependency of this response to local setting characteristics, and the diversity of the approaches limits the possibilities for a global analysis.

We propose a new approach to constrain changes in erosion rates over the Pleistocene-Holocene transition, using the well-known concept that erosion rates derived from concentrations average over a timescale inversely proportional to the erosion rate. By combining TCN data with topographic information, we constrain the amplitude of erosion changes across neighboring basins that are eroding at different rates. We highlight a complex pattern, with an overall pronounced several-fold increase in denudation rate when entering the Holocene. Intertropical high-relief settings appear to be more likely to displaying an increase in denudation rates, which might reflect a stronger sensitivity of these landscapes to periglacial processes, monsoon regime or threshold hillslope dynamics.

How to cite: Godard, V., Mudd, S., and Attal, M.: Global Pleistocene-Holocene variations in denudation rates constrained from a joint analysis of cosmogenic nuclides and morphological data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6340, https://doi.org/10.5194/egusphere-egu25-6340, 2025.

In recent decades, the quantification of Earth surface processes such as erosion, sediment transport, and deposition has gained increasing attention, with a focus on investigating their interplay across different spatial and temporal scales. This study contributes to address these challenges by combining in-situ cosmogenic ¹⁰Be isotopic analyses with a modified version of the Erosion Potential Model (EPM) to explore landscape and sediment dynamics in the Sfalassà stream catchment in Calabria, southern Italy.

A total of 26 samples, including river sands of two different grain sizes and rock samples, were collected to estimate long-term erosion rates, sediment residence times (average exposure ages), and rates of vertical river dissection across the catchment. The adoption of ¹⁰Be cosmogenic nuclide enables a detailed understanding of erosion and sediment transport processes on millennial timescales, providing time frames for the main processes that have shaped the basin. The Sfalassà catchment, characterized by a diverse range of lithologies, geomorphological units, vegetation cover, land uses, and anthropogenic activities, was selected as a representative pilot basin in the central Mediterranean area. Sampling was conducted across the main channel and its tributaries to ensure comprehensive coverage. Field surveys formed the core of our sampling strategy, supplemented by aerial photo interpretation, GIS and thematic mapping analyses to enhance site selection.

The EPM was upgraded using the catchment’s geological and pedological erodibility parameters. The specific weights of geological parameters and the differentiation of lithological classes assigned to various lithologies available in the literature were modified, trying to enhance the model accuracy for estimating medium-term erosion rates. This adjustment involved an integration of the spatial distribution of rock outcrops with that of major soil types, focusing on their varying susceptibility to surface erosion. Additionally, rainfall data were extrapolated at different elevations using a regression function of data from weather stations. In contrast to the EPM, the ¹⁰Be analyses provided precise and direct in situ measurements, enriching our understanding of catchment-scale erosion processes through the integration of methodologies.

Despite operating on different temporal scales, the integration of isotopic data with the EPM may enhance the model’s accuracy. This synergy may provide a more robust framework for the quantification of sediment fluxes and erosion process modeling, contributing to a deeper understanding of sediment dynamics. This interdisciplinary approach not only sheds light on the connectivity between sediment source areas and the drainage system but can also suggest practical tools for assessing and managing sediment dynamics and coastal erosion risks. Based on the rates at which river sediments feed coastal areas, it highlights conditions of balance/unbalance in the sedimentary input, thus emphasizing broader geomorphological implications.

The research is part of the "TECH4YOU – Technologies for climate change adaptation and quality of life improvement" project, funded by Next Generation EU (PNRR M4.C2.1.5). By combining geochronological techniques with numerical modeling, this study contributes to advancing methodologies for basin-scale investigations, offering replicable protocols applicable to diverse geo-environmental contexts and improving our understanding of sedimentary processes from source to sink.

How to cite: De Cesare, P., Egli, M., Tikhomirov, D., Christl, M., Imbrogno, G., and Scarciglia, F.: Integrating 10Be analyses and an empirical erosion model to unveil catchment-scale landscape and sediment dynamics, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8861, https://doi.org/10.5194/egusphere-egu25-8861, 2025.

Quartz is one of the most common minerals in the Earth’s crust and can be found in a large diversity of geological environments. Due to its ubiquity and resilience towards weathering, it is a major mineralogical component in terrestrial sediments. A good understanding of quartz properties can thus be very useful to understand quartz dynamics and thereby Earth surface dynamic processes such as erosion, transport and deposition.

Electron spin resonance (ESR) spectroscopy is a method which allows to characterize paramagnetic centres (unpaired electrons related to geochemical impurities) in quartz. Two paramagnetic centres generally present in quartz (Al and Ti-Li centres) are sensitive to ionizing radiation on the one hand and light exposure on the other hand and can be used to date the transport and deposition of quartz in the timescale of ca. 50 ka to 3 Ma making ESR dating of quartz an excellent tool to constrain quaternary geological processes.

While this method has continuously been developed and improved over the last decades, some key aspects of the method, notably the sample dependency of dose response and sensitivity, remain poorly understood, leading to difficulties or even impossibility to date some samples.

In this contribution, we aim to identify the influence of source-specific signature and sediment cycling on ESR dose response and sensitivity. Our research focuses on the well characterized Strengbach catchment in the Vosges mountains (NE France) which drains a large variety of quartz bearing rocks (granites, gneiss, sandstones). Quartz extracted from different bedrocks was analyzed geochemically by Laser ablation coupled to mass spectrometry (LA-ICPMS) and by ESR. Subsequently, the quartz was artificially irradiated and bleached in order to reproduce natural sediment cycling and reinvestigated by ESR. We discuss the observed ESR differences in relation with their geochemical signature and examine possible reasons for the observed results.

How to cite: Heller, B., Voinchet, P., Chourio Camacho, D. N., Aupart, C., Rixhon, G., Lach, P., Valla, P., Boulay, M., Rizza, M., and Tissoux, H.: ESR dating of quartz revisited: towards a better understanding of ESR sensibilities through investigation of different quartz types and experimental reproduction of sediment cycling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10339, https://doi.org/10.5194/egusphere-egu25-10339, 2025.

Latest with the onset of the Neolithic period, humans have modified the landscape by farming, extracting natural resources, and reducing forest cover. Many studies have demonstrated that these human activities can increase the vulnerability of soils to erosion. However, the magnitude and duration to which such activities have reduced forest cover and accelerated soil erosion have been mainly based on proxy data derived from sediment and pollen records. In this study, we test a new methodological approach by coupling leaf wax isotope analyses with erosion rate measurements based on ¹⁰Be and ¹⁴C to investigate the impact of human activities during the Holocene on vegetation and erosion rates on the island of Elba, Italy. We hypothesize that meeting the substantial fuel demands for iron smelting on Elba Island, initiated by the Etruscans and subsequently continued by the Romans from the 4^th century BCE onwards, exerted significant pressure on the island's forest ecosystems. This reduction of forest cover likely accelerated soil erosion processes, driven by the removal of vegetative cover essential for soil stability. To test our hypothesis, we measured cosmogenic ¹⁰Be and ¹⁴C in quartz from stream sediment samples to reconstruct changes in erosion rates during the Holocene. We complemented this with leaf wax isotope analysis (δ²H, δ¹³C) from floodplain sediment cores to explore vegetation and hydrological changes. Due to the shorter half-life of ¹⁴C compared to ¹⁰Be (~5.7 kyr and ~1.4 Myr, respectively), ¹⁴C records erosion on shorter time scales than ¹⁰Be. Apparent erosion rates obtained from the two nuclides show a marked offset: ¹⁴C apparent erosion rates of 129 to 1080 mm kyr ^-1 are up to two orders of magnitude faster than the corresponding ¹⁰Be erosion rates of 20 to 50 mm kyr ^-1. This discrepancy can be explained by a substantial increase in erosion toward modern times. To identify the timing of erosion change and thickness of soil loss, we apply a Markov chain Monte Carlo inversion with several simple erosion histories. These data allow us to compare the history of land use with vegetation change and the erosion response on a landscape scale.

How to cite: Cerón Espejo, N., Scherler, D., Bernhardt, A., Rohrmann, A., Bebermeier, W., Becker, F., Wittmann, H., Dunai, T., Fulop, R., and Ott, R.: Erosion rate response to the reduction of forest cover following metallurgical activities on Elba Island (Italy), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10549, https://doi.org/10.5194/egusphere-egu25-10549, 2025.

Rock glaciers are common permafrost features in mountain landscapes around the globe. They pose a geo hazardous risk¹ sourcing large amounts of debris while also acting as aquifers storing large amounts of water². Due to limited dating efforts on rock glaciers, their long-term (i.e. centennial to millennial scale) dynamics and response to climate variability are poorly understood. Short term observations, via GPS, InSAR, UAVSAR, Lidar or feature tracking, show acceleration of flow rates of rock glaciers in all mountain regions³. Understanding past dynamics is key to project rock glacier behavior under future global warming.
This study combines cosmogenic radionuclide (CRN), and rock surface dating based on optically stimulated luminescence (OSL RSD) on a rock glacier in the Uinta Mountains (Utah, USA, 3300 m asl.). CRN dating of 8 quartzite boulders has been conducted by Munroe et al.⁴ and the same boulders were sampled for OSL RSD. 4 additional OSL samples of dark red quartzite were taken for increased dating resolution during fieldwork in 2024. The independent cosmogenic age control allows us to (i) test the applicability of OSL RSD in a high-altitude periglacial setting, (ii) investigate the sensitivity of the model parameters that are folded into the OSL bleaching-with-depth model and (iii) based on conceptual work by Sohbati et al.⁵ and Lehmann et al.⁶ to determine rock surface erosion rates of the quarzitic host lithology.

1.    Schoeneich, P. et al. Velocity Changes of Rock Glaciers and Induced Hazards. In Engineering Geology for Society and Territory - Volume 1, edited by G. Lollino, A. Manconi, J. Clague, W. Shan & M. Chiarle (Springer International Publishing, Cham, 2015), pp. 223–227.
2.    Jones, D. B., Harrison, S., Anderson, K. & Whalley, W. B. Rock glaciers and mountain hydrology: A review. Earth-Science Reviews 193, 66–90; 10.1016/j.earscirev.2019.04.001 (2019).
3.    Pellet, C. et al. Rock Glacier Velocity. In State of the Climate in 2023, edited by J. Blunden & T. Boyer (2024), pp. 44–46.
4.    Munroe, J. S., Laabs, B. J. C., Corbett, L. B., Bierman, P. R. & Handwerger, A. L. Rock Glacier Movement and Debris Transport Over Annual to Multi‐Millennial Timescales. JGR Earth Surface 129; 10.1029/2023JF007453 (2024).
5.    Sohbati, R. et al. Centennial- to millennial-scale hard rock erosion rates deduced from luminescence-depth profiles. Earth and Planetary Science Letters 493, 218–230; 10.1016/j.epsl.2018.04.017 (2018).
6.    Lehmann, B., Herman, F., Valla, P. G., King, G. E. & Biswas, R. H. Evaluating post-glacial bedrock erosion and surface exposure duration by coupling in situ optically stimulated luminescence and 10Be dating. Earth Surf. Dynam. 7, 633–662; 10.5194/esurf-7-633-2019 (2019).

How to cite: Sperlich, D., Meyer, M., and Munroe, J.: Combining Cosmogenic Surface-Exposure and OSL Rock Surface Dating on a rock glacier in the Uinta Mountains (USA) - a comparative methodological study on exposure ages and a novel tool to constrain host rock erosion rates, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10798, https://doi.org/10.5194/egusphere-egu25-10798, 2025.

Many mountain glaciers have experienced an increase in supraglacial debris cover due to climate change. Understanding sediment transport processes in glacier systems is important because the accumulation of supraglacial debris affects glacier evolution and response to climate change. Tracking debris and sediment transport through glacial catchments is difficult and thus, the pathway and time scale of englacially transported debris are relatively poorly understood. We quantify the englacial transport time of debris within a glacier using a novel method combining luminescence rock surface burial dating and ice-flow modelling (Margirier et al., 2025). Our study focuses on the Mer de Glace catchment, French Alps, where supraglacial debris cover has expanded over the past half-century.

We collected granitic rock debris clasts (4–22 cm in diameter) that were embedded in ice in the ablation area of Mer de Glace, which we expected to have undergone varying durations of englacial transport. The clasts were assumed to originate from headwalls (paraglacial areas), where they were exposed to daylight before falling onto the glacier and being transported englacially. Cores were extracted from the unexposed rock surfaces and sliced into ~0.9 mm thick discs for luminescence dating. We measured the luminescence signal using a single-aliquot regenerative dose protocol comprising infra-red stimulation, followed by blue stimulation to explore the signals of different minerals with different luminescence properties. Of the 29 samples investigated, 19 were well bleached prior to burial, exhibiting a clear plateau in luminescence signals with depth, and 15 samples have been successfully dated giving burial ages between 0.58 ± 0.13 ka and 6.73 ± 0.72 ka. Except for two samples that are significantly older, luminescence ages are consistent across the glacier, which suggest that the rate of sediment transport is broadly consistent across the ice. Future work will contrast the englacial burial time obtained with luminescence dating with those predicted by an ice-flow model of particle transport trajectories within the Mer de Glace. This will allow particle sources to be better identified and to understand the ice dynamics of the glacier.

Reference:

Margirier A., J. Brondex, A.V. Rowan, C. Schmidt, V.K. Pedersen, B. Lehmann, L.S. Anderson, R. Veness, C.S. Watson, D. Swift, G.E. King (2025), Tracking sediment transport through Miage Glacier, Italy, using a Lagrangian approach with luminescence rock surface burial dating of englacial clasts, JGR: Earth Surface.

How to cite: Rodari, L., Audrey, M., King, G. E., Rowan, A. V., Schmidt, C., and Jouvet, G.: Combined luminescence dating and ice-flow modelling to track Holocene sediment transport through Mer de Glace, French Alps, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11697, https://doi.org/10.5194/egusphere-egu25-11697, 2025.

Neotectonics of Eastern Türkiye is mainly characterized by immensely complex deformation patterns driven by the convergence between the Arabian Plate and the Eastern Anatolian Plateau. This apparent convergence accommodates a primary intraplate strike-slip fault system, encompassing the North Anatolian Fault Zone (NAFZ) and the East Anatolian Fault System (EAFS). Recent seismic events, such as the 24 January 2020 (Mw6.8) earthquake and the 6 February 2023 doublet earthquake (Mw7.7 and Mw7.6), dramatically highlight the structural intricacy of the region and signify that the conundrum is much broader than initially thought. The ruptures occurred after the two earthquake sets abruptly terminated the onset of the Pütürge segment residing in the EAFS. The segment splits the Şiro Valley in two and is hypothesized to accumulate strain, potentially driven by aseismic creep.

Our multidisciplinary investigations focus on the deformation and seismic potential of the Pütürge segment, emphasizing critical questions regarding its long-term slip rate, uplift rate, and past earthquake cycle. Geochronological methods, including Optically Stimulated Luminescence (OSL) and Radiocarbon (¹⁴C) dating methods, have been applied to Quaternary River terrace deposits along the Şiro Valley. Three distinct terrace levels (T0, T1, and T2) were identified by measuring stratigraphic sections, with thickness of approximately ~1 m, ~11 m, and ~12 m, respectively. These terraces, shaped by predominantly sinistral strike-slip movement with somewhat oblique components, stand out as geologic archives of tectonic and fluvial activity.  The terrace deposits primarily consist of clays, silts, sands with organic material, gravels, and boulder stemming from the Maden Complex and Pütürge Metamorphics, rich in quartz and feldspar. Preliminary OSL dating employing the single-aliquot regenerative dose (SAR) technique on quartz grains from the T1 terrace yielded ages ranging from 11.42 ± 1.97 ka to 28.18 ± 3.00 ka at the Gölkan site and 12.82 ± 0.95 ka to 30.92 ± 4.85 ka at the Yazıca site, located on the northern and southern margins of the Şiro Valley, respectively. Further analyses of samples from additional terrace levels are still ongoing.

These preliminary yet clear findings suggest that the Pütürge segment has experienced significant post-Quaternary tectonic activity. Furthermore, the seismogenesis of the Pütürge segment, in conjunction with known geological information, raises another issue to consider. The fault's seismicity patterns and parameters will be examined in that sense. Spatial and temporal Gutenberg-Richter recurrence parameters are valuable knowledge that helps us to calculate the return periods of apparent and possible scenario earthquakes. The deformation pattern will be tested to see if it is used as a key indicator of how the Valley is heading through and evolving. As the fieldwork, lab tests, and computational modeling have been underway and are close to finalization, this study aims to present preliminary geochronological dating results inferred from Quaternary fluvial terrace formations. Also, it explores their implications for the seismic hazard and tectonic evolution of the East Anatolian Fault System. This study is fully supported by the Scientific and Technological Research Council of Turkey (TÜBİTAK; Project No:122Y266).

How to cite: Akgün, E., Softa, M., Nas, M., Yüksel, M., Spencer, J. Q. G., Sözbilir, H., Aksoy, E., Gürgöze, S., and Topal, S.: Evidence for Long-term Quaternary Tectonic Activity of the Pütürge Segment in the East Anatolian Fault System (EAFS) by Using Luminescence and Radiocarbon Dating Methods, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12012, https://doi.org/10.5194/egusphere-egu25-12012, 2025.

Cosmogenic nuclides measured in depth-profiles are a valuable tool for reconstructing the depositional and erosional history of sedimentary sequences. The burial ages of these sequences can be determined by measuring cosmogenic nuclide pairs such as ²⁶Al and ¹⁰Be. However, some conventional approaches neglect post-burial nuclide production, a major source of error.

A new model, CosmoChron (Sørensen et al., 2024, Quat. Geochron. 85, 101618), enables a more versatile and comprehensive analysis by integrating nuclide data with independent age constraints, such as OSL dating or magnetostratigraphy. CosmoChron employs probabilistic inverse modeling, incorporating prior information about accumulation processes and sample origins. The forward model accounts for ²⁶Al/¹⁰Be ratios, pre-burial conditions, radioactive decay, post-burial production, and unconformities, allowing for more precise reconstructions, including hiatuses at unconformities.

We demonstrate CosmoChron via two case studies: (1) a drill-core at Wapenveld (the Netherlands) penetrates the Early Pleistocene “Hattem” beds—thought to be among the earliest glacigenic deposits in Europe. The samples are from three distinct layers with several unconformities and a stratigraphic age constraint at the base. And (2) Fisher Valley (Utah, USA) contains samples from Early Pleistocene alluvial sediments with depth-profile burial ages published by Balco and Stone (2005, ESPL 30, 1051-1067). We recalculate the age-depth relationship, compare the methods, and explore the differences in the results.

We discuss the advantages and limitations of depth-profiles and CosmoChron, emphasizing its ability to provide detailed temporal reconstructions while requiring robust site-specific information.

How to cite: Ylä-Mella, L., Wagner, K., Sørensen, A. L., Knudsen, M. F., Busschers, F., Bakker, M., Eriksen, B. L., Andersen, J. L., Olsen, J., Margold, M., and Jansen, J. D.: Unraveling burial histories with CosmoChron, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12361, https://doi.org/10.5194/egusphere-egu25-12361, 2025.

Exposure dating has become a critical tool in addressing specific geoscientific challenges, including glaciology, active fault studies, and environmental reconstructions. Cosmogenic exposure dating (e.g., ³⁶Cl) and luminescence surface exposure dating are widely used techniques, often complementing each other. In active tectonic studies across Türkiye, cosmogenic ³⁶Cl dating has been applied extensively to active faults to elucidate paleoseismic histories and slip rates. Although luminescence surface exposure dating is relatively new in this context, its initial applications along the Manisa Fault in Western Türkiye have shown promising results. In this study, we focus on the Kalafat and Yavansu faults within the Kuşadası Fault Zone, which is considered the eastern continuation of the Samos Fault that ruptured during the 30 October 2020 earthquake. This region, characterized by N-S extensional tectonics with horst-graben structures and normal faulting, offers well-preserved fault scarps that serve as natural laboratories for exposure dating.

Preliminary luminescence depth profiling of scarp samples and optically stimulated luminescence (OSL) dating of associated colluvial wedges provide valuable insights into the paleoseismic history of these faults: (i) Luminescence profiling revealed stable signal limits at ~6 mm, with intensity increasing with depth; (ii) Calibration against prior cosmogenic dating yielded uppermost ages of ~15 ka for KF and ~8 ka for YF; (iii) OSL dating of colluvial wedge bases produced ages of 16.56 ± 1.77 ka for KF and 14.45 ± 0.74 ka for YF. These results indicate significant seismic activity along both faults during the Late Pleistocene, consistent with regional tectonic processes. This research underscores the utility of integrating luminescence surface exposure techniques with cosmogenic methods for refining paleoseismic chronologies. This study is fully supported by the Dokuz Eylül University Scientific Research Project (Project No. FBA-2023-3042).

How to cite: Softa, M., Şahiner, E., Spencer, J. Q. G., Sözbilir, H., Yüksel, M., Utku, M., Akçar, N., Kırallı, S., Yerli, B., Çakır, R., Büyüktopçu, F. M., and Deniz, F.: Luminescence Surface Exposure Dating and Paleoseismic Insights from the Kuşadası Fault Zone, Western Türkiye, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14332, https://doi.org/10.5194/egusphere-egu25-14332, 2025.

Cosmogenic nuclide concentrations are typically inverted for erosion and soil production rates under the assumption that these rates are temporally invariant, and that soil thickness is in steady state. Yet, transience in process rates and soil thickness is expected to occur in landscapes that are experiencing changes in land use, tectonic uplift, and climate. Pairing cosmogenic nuclides with different half-lives provides a means for resolving transience if process rates are sufficiently slow that radioactive decay is significant. Here, we examine ¹⁰Be and ²⁶Al concentrations in quartz collected from saprolite at 6 positions along a hillslope transect in the Belgian Ardennes. This transect runs from a low relief paleosurface to the bottom of a catchment incised ca. 30 meters into the paleosurface. We find that all measured ²⁶Al/¹⁰Be ratios are below the production ratio and that the ratio on the paleosurface is near secular equilibrium. Furthermore, all samples plot below the steady-state erosion line on an ²⁶Al/¹⁰Be two-isotope plot. Given the geomorphic position of the site on a regional topographic high, it is unlikely that the ²⁶Al and ¹⁰Be concentrations can be explained by burial by sediment to a depth sufficient to shut-off cosmogenic nuclide production. Rather, we model the isotope concentrations as resulting from transience in the soil production rate and soil thickness. The model indicates that the mean soil thickness over the integration timescale of the cosmogenic nuclide signal exceeds the modern measured soil thickness.

How to cite: Moore, A., Li, Y., Henrion, M., Christl, M., Gautschi, P., Jonard, F., Lambot, S., Van Oost, K., Opfergelt, S., and Vanacker, V.: Using paired cosmogenic 26Al and 10Be to study landscape transience in the Belgian Ardennes , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15019, https://doi.org/10.5194/egusphere-egu25-15019, 2025.

Understanding the temporal pace and spatial pattern of alluvial fan-river system evolution in front of active orogens would help us properly extract information of active tectonics and increase our resilience to landscape evolution of this habitable area. The northern piedmont of Chinese Tianshan, where the landscape is shaped by the interactions among fan building and abandonment, river aggradation and degradation and fault related fold growth. Comprehensive studies have been performed to delineate fan distribution, river incision and fold growth history. However, it is lack of investigation on the detailed spatial and temporal pattern of river channel evolution in a full aggradation and degradation cycle, which hinders formulating the law for alluvial system evolution. In this study, we address this question by using luminescence dating technique to constrain the chronological sequences of sandy samples collected from the terrace deposits. The architecture of the terrace deposits is characterized by upper very coarse gravels and cobbles (VCGC) unit and lower medium and coarse gravels (MCG) unit. The VCGC unit is attributed to the deposition during the incisional phase while the MCG unit is related to the aggradation phase of Jingou River. The coupled luminescence ages from VCGC and MCG units suggested a gradual and slow aggradation of 25 m sediments from 16 ka to 8 ka ago, which was followed by an almost instant incision around 5.5 ka ago by 25 m at least. These observations echo to the patterns unveiled by previous numerical studies. Further, the abandonment ages determined by employing the samples from the MCG unit of the most extensively distributed terrace surface T5 along the middle reach of Jingou river decrease in downstream direction from 16 ka to 5.5 ka, which poses an evidence of diachronous terrace formation. The implication of asymmetric degradation-aggradation phases and diachronous terrace formation will be discussed, with respect to the mass redistribution processes and active tectonics characterization of the alluvial fan and river system.

How to cite: Qin, J., Li, K., Chen, J., Liu, J., and Yao, Y.: Unconventional spatial and temporal pattern of alluvial river aggradation and degradation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16613, https://doi.org/10.5194/egusphere-egu25-16613, 2025.

Quantifying erosion and linking its topographic imprint to underlying controls is critical for understanding landscape evolution and sediment dynamics across time and space. Over the past decades, catchment-wide denudation rates from cosmogenic ¹⁰Be concentrations in river sediment emerged as a standard method for quantifying erosion. As such, ¹⁰Be-based erosion data have been instrumental in proposing different controlling mechanisms and processes for distinct mountain ranges. These include tectonic uplift, often modulated by periglacial processes, precipitation gradients, bedrock erodibility, landslide frequency, and most prominently, hillslope morphology, i.e., the slope angle. However, disentangling the individual effects of these processes has proven challenging, and often, the correlation between erosion rates and topography is observed only up to threshold values, e.g., slope angles <30° in the European Alps. One potential reason for this is that most data on the erosion rate are obtained for catchments on a regional scale (>10¹ to 10³ km²), where sediment mixing and storage, as well as the (dis)connectivity and stochastic nature of sediment sources, obscure the influence of individual processes on local erosion dynamics.

Here we present 16 new detrital ¹⁰Be erosion rates from two nested river catchments in Switzerland: the Luetschine in the Alps and the Schwarzwasser in the Pre-Alps. Despite being close (<50 km between outlets), these catchments display significant differences in topography within and between them. While the Schwarzwasser catchments are characterized by gentle slopes (mean values <21°) and mean altitudes of <1500 m a.s.l., the Luetschine catchments drain the northern rim of the highly elevated Aar Massif, resulting in steeper (up to 37° for mean slopes) and higher (mean altitudes of >2000 m a.s.l.) landscapes. To investigate how these topographic variations influence erosion rates, we sampled sub-catchments with progressively smaller drainage areas ranging from over 340 km² to less than 3 km² in the smallest upstream tributaries.

Overall, our resulting detrital ¹⁰Be erosion rates for the entire catchments are, 3-4 times higher for the Luetschine catchment than for the Schwarzwasser. They align with the general regional trend and the first-order control by the topographic uplift rate inferred by previous studies. In more detail, even in the topographically homogeneous Schwarzwasser basin, where erosion rates generally correlate with the average slope angle, the erosion rates internally vary by up to a factor of two, with the delivery of landslide material to the stream being the primary control. In the Luetschine basin, which comprises highly heterogeneous landscapes, the erosion rates differ by a factor of up to five among sub-catchments. Here, the highest and lowest values are obtained from the smallest catchments, and they do not correlate with slope angles in these steeper catchments (> 30 ° mean slope). Instead, locally different mechanisms, such as peri-glacial and glacial erosion, effectively modulate erosion rates. These findings reconcile contrasting control mechanisms for mountain range scale erosion on a local scale within the close geographical vicinity of our study area. These results underscore the need to sample smaller catchments and to consider topographic heterogeneity to link erosion and topography in steep environments.

How to cite: Mair, D., von Allmen, J., Ruffiner, P., Binaghi, M., Schmidt, C., Garipova, S., Akçar, N., Christl, M., and Schlunegger, F.: Linking highly variable Detrital 10Be Erosion Rates to heterogeneous Topography in Small and Alpine Catchments, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18560, https://doi.org/10.5194/egusphere-egu25-18560, 2025.

Joint inversion within a Bayesian framework provides a robust means to estimate uncertainties by integrating the inherent variability of multiple data sets used in the inversion process. In this study, we reconstruct the surface uplift history of mantle origin in NW Iberia and quantify its associated uncertainties. Using a novel reversible-jump Markov chain Monte Carlo (RJ-MCMC) Bayesian algorithm, we perform a joint inversion of topographic data and river-sand 10Be concentrations in quartz to decode the uplift history. This probabilistic approach yields an ensemble of solutions that explore diverse combinations of model parameters, enabling detailed uncertainty quantification in the timing and magnitude of uplift rate changes.

Our forward model employs non-linear analytical solutions of the stream power incision model, which defines incision I = KA^mSⁿ as a function of S, the local channel gradient; A, the upstream drainage area; and K, the erodibility parameter. The model is coupled with the CAIRN method (Mudd et al., 2016, Earth Surface Dynamics, 4, 655-674) to invert Be-10 concentrations at the catchment scale to calibrate the K and n parameters with erosion rates.

We apply this methodology to the Atlantic rivers draining NW, where deep canyons dissect low-relief erosional surfaces formed over the last 100 million years, and apply the calibration to other settings in Central Iberia. Our results suggest that the transient topography reflects a regional late Cenozoic uplift of several hundred meters, likely driven by mantle-related, continent-scale processes. This study underscores the utility of probabilistic joint inversion in unraveling complex geodynamic histories and their uncertainties.

How to cite: Babault, J., Bodet, L., Arroucau, P., Charco, M., Figueiredo, P., Owen, L. A., Caffee, M., Fullea, J., Negredo, A., and Van Den Driessche, J.: Handling Uncertainties in Mantle-Driven Late Cenozoic Surface Uplift of NW Iberia Using Bayesian Joint Inversion of River Profiles and 10Be Cosmogenic Nuclide Concentrations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20102, https://doi.org/10.5194/egusphere-egu25-20102, 2025.

CFD (computational fluid dynamics)-DEM (discrete element method) model has been widely applied in the simulation of the multiphase flow involving granular materials, but it’s time-consuming for the calculation of a large number of particles with different sizes in DEM. In this study, a model based on the computational micropolar fluid dynamics and discrete element method, viz. a CMFD-DEM model, is proposed to describe the coupling system that consists of gas-liquid two phases and discrete particles with different sizes. In this model, micropolar fluid model is employed to describe the mixture of the pure fluid with fine particles, while discrete element method is used to calculate the motion of the larger particles. In addition, VOF (volume of fluid) method is adopted to track the free surface of the liquid. The implementation of the CMFD-DEM model is based on the open source software, OpenFOAM and LIGGGHTS, and is validated in single particle sedimentation and particles pouring into quiescent water cases. Then, the simulation of debris flow is carried out. The results show that specific dynamic behaviors of debris flow can be reproduced by CMFD-DEM model. The average velocity and runout of debris flow are decreased with the increase of micropolar parameter N/L. Through the comparisons to the exiting results, it suggests that CMFD-DEM model is capable to describe the multi-size effect of the granular materials in debris flow.

How to cite: Wang, L., Chu, X., and Sun, H.: An extended CFD-DEM model based on micropolar fluid for debris flow, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3598, https://doi.org/10.5194/egusphere-egu25-3598, 2025.

Transport of granular materials on Earth and planetary surfaces are at the heart of landscape dynamics and geohazards. These transport phenomena are controlled by particle-scale mechanisms, including particle motion, collisions, and interactions with the ambient fluid, which highlights the importance of particle-resolved measurements in physical experiments. However, despite recent progress in particle tracking velocimetry (PTV) for spherical (and regularly shaped) particles, there still lacks a robust technique in tracking and analyzing the motion of non-spherical particles, particularly because conventional PTV cannot identify moving objects of an arbitrary shape. This limitation largely compromises our particle-scale understanding of the transport of natural granular materials with a wide range of shapes and sizes. To tackle this issue, we propose a novel deep learning-based PTV framework for arbitrarily shaped and sized particles, which consists of a real-time computer vision algorithm called YOLO (you only look once) and an accurate inter-frame matching algorithm based on Kalman filtering. The proposed PTV framework is validated in various granular flow and sediment transport scenarios, using high-resolution data obtained from discrete element method simulations and small-scale physical experiments. Using this new technique, we are able to precisely analyze the kinematics information of spherical, non-spherical, and mixed particles with different concentrations in a series of open channel bedload transport experiments. Scaling relations are obtained between the sediment flux and bed shear stress to reveal the effects of particle shape and composition on the sediment transport dynamics across bedload and sheet flow conditions. The proposed PTV technique and its potential applications are expected to provide a new avenue for future research on the micromechanical aspects of geophysical granular flow and sediment transport.

How to cite: Su, W., Jing, L., and Xu, M.: Deep learning-based particle tracking velocimetry (PTV) for spherical and non-spherical particles: Application to granular flow and sediment transport, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7708, https://doi.org/10.5194/egusphere-egu25-7708, 2025.

Step-pools are common bedforms in mountain streams and have been utilized in river restoration or fish passage projects around the world. Step-pool units exhibit highly non-uniform hydraulic characteristics which have been reported to closely interact with the morphological evolution. Further understanding towards these interactions builds the basis for better prediction of channel evolution and more advanced design of artificial step-pool system. However, detailed information on the flow-morphology interactions has been limited due to the difficulty in measuring the flow structures or the flow forces in a step-pool unit.

To fill in this knowledge gap, we established an approach combining physical experiment and computational fluid dynamics (CFD) simulation for a step-pool unit made of natural grains at six flow conditions. Structure from motion (SfM) was used to capture the detailed 3D reconstructions of the bed surfaces with various conditions of pool scour. The hydraulic measurement was applied both as input data at the inlet boundary and also in the validation for the CFD model. The high-resolution 3D flow structures for the step-pool unit were visualized, as well as the distributions of flow forces from both pressure and shear stress.

The results illustrate the segmentation of flow velocity downstream of the step, i.e., the integral recirculation cell at the water surface, streamwise vortices formed at the step toe, and high-speed flow in between, resulting from the complex morphology of the step-pool unit. Both the recirculation cells at the water surface and the step toe perform as energy dissipaters to the flow with comparable magnitudes. Pool scour development during flow increase leads to the expansion of the recirculation cells until step-pool failure occurs. Significant transverse variability of the flow forces from both the shear stress and pressure has been revealed. The flow forces in both streamwise and transverse directions are closely related to the flow structures and morphology in the unit. The ratios between skin and form drag have large variations at low flows while show a relatively limited range of 0.05-0.1 at high flows, suggesting a small proportion occupied by the skin resistance in the total flow resistance in the step-pool channel. The drag coefficient of the step-pool unit is around 0.3 at high flows. Our results highlight the feasibility of the approach combining physical and numerical modeling in investigating the complex flow-morphology interactions of step-pool features.

How to cite: Zhang, C., Hassan, M., and Xu, Y.: Investigating interactions between flow and morphology in a step-pool unit combining physical and numerical modeling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7900, https://doi.org/10.5194/egusphere-egu25-7900, 2025.

Geophysical granular flow is ubiquitous in nature and plays a crucial role in shaping the landscape (hillslope creep, riverbed evolution) and causing geohazards (landslide, debris flow). Small-scale models are an effective way to understand these natural phenomena at large scales. However, finite-size effects inevitably occur due to the multi-scale nature of granular materials, hindering integration of mechanisms obtained from small-scale investigations and continuum models (e.g., granular flow rheology) for large-scale applications. Here we use granular column collapse as a model case to address finite-size effects in granular flows from a novel rheological perspective. We computationally simulate column collapse of varying system-to-particle size ratios using the discrete element method and extract detailed local rheological information during the flow via a coarse-graining technique. We find a disproportional increase in the dimensionless runout distance with the system-to-grain size ratio and a significant difference in the dynamic process. This discrepancy is reflected in the μ(I) curve as non-collapsed data at low inertial number regimes, but casting the data into a non-local rheology framework proposed by Kim and Kamrin (2020) leads to data collapse onto a single master curve for all simulations. This indicates that the finite-size effect is controlled by velocity fluctuations at the grain scale and is a manifestation of the non-locality of granular materials. As a result, the introduction of an intermediate length scale that reflects velocity fluctuations is expected to enable accurate modeling of geophysical granular flows with varying system and particle sizes in a unified continuum framework. It also provides a new perspective for continuum modeling of polydispersity, size segregation, hysteresis, and other size-dependent phenomena in geophysical granular systems.

How to cite: Xia, J., Jing, L., and Peng, M.: Finite-Size Effects in Geophysical Granular Flow from a Nonlocal Rheology Perspective, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7958, https://doi.org/10.5194/egusphere-egu25-7958, 2025.

We present the results of laboratory experiments investigating the intense transport of bimodal bed load under high bed shear conditions in a tilting flume. Particles of two lightweight sediment fractions, differing in size, tend to separate during transport above the plane surface of an eroded mobile bed. Coarser fraction particles are predominantly present in the collisional layer above the bed, while finer fraction particles are primarily concentrated in the interfacial layer, which develops between the eroded bed and the collisional layer. This observed stratification of transported fractions influences their respective contributions to the total bed load discharge through the flume. Vertical distributions of local velocity and volumetric concentration were measured across the flow depth for each fraction separately, allowing the determination of each fraction's proportion in the total discharge. The experimental results were combined with a previously collected dataset to compare the discharges of bimodal and unimodal sediments under hydraulically similar conditions. Additionally, the experimentally determined discharges were evaluated against predictions from transport models designed for intense unimodal and bimodal bed loads.

How to cite: Matousek, V., Krupicka, J., Picek, T., and Svoboda, L.: Quantification of intense transport of fractions of stratified bimodal bed load based on measured distributions of velocity and concentration, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8700, https://doi.org/10.5194/egusphere-egu25-8700, 2025.

Sediment transport dynamics are of great importance in understanding geophysical flows, where determining the threshold conditions for the initiation of sediment motion presents a complex challenge. In a pioneering work, Shields (1936) established the Shields’ criterion to assess the critical shear stress (τ_c) required for sediment motion in non-turbulent flows. Although this approach has significant advantages, including a robust empirical foundation and the implementation of non-dimensional critical shear stress, it is valid for limited conditions since it oversimplifies vital aspects such as sediment heterogeneity and complex flow interactions.

In turbulent flows, the effective critical shear stress acting on a grain may become higher than that measured in the case of laminar flows (i.e., the average critical stress, τ_c, defined by Shields, 1936) as a result of fluctuations in the shear stress (τ′). Owing to this, in geophysical turbulent flows near the threshold of motion, neither the driving nor the resisting parameters of sediment motion have crisp values; instead, they may be considered probabilistic parameters. The reliability-based approach is applied here in to handle the complex nature of the initiation of sediment motion.

This study aims to present preliminary results of research that aims to enhance the knowledge of incipient motion by applying a reliability-based analysis of Shields’ criterion based on the theory and empirical equations adopted by Zanke (2003). In this analysis, the turbulence parameter (n) and angle of repose (ϕ) are introduced as key parameters regarding the initiation of sediment motion. These parameters are generated as random variables by means of Monte Carlo Simulations, introducing various probabilistic distributions (e.g., normal, log-normal, triangular, gamma) and statistical moments (e.g., mean, standard deviation).

By simulating a wide range of angles of repose and turbulence parameters with Monte Carlo Simulations, the inherent uncertainties in sediment transport and the complexity of hydrodynamic models are incorporated. In this work critical shear stresses of thousands of grains are assessed for different grain Reynolds numbers. As a result, threshold of motion curves are probabilistically derived, indicating confidence for grain entrainment, and establishing a model that enables risk assessment and decision-making for a wide range of scenarios. Comparisons of model results with empirical data show that the model captures the complex physical process.

How to cite: Baysal, S., Kırca, V. Ş. Ö., and Valyrakis, M.: Reliability-Based Analysis of Initiation of Sediment Motion on Movable Bed, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8745, https://doi.org/10.5194/egusphere-egu25-8745, 2025.

Avalanches of dry granular materials, such as rocks, snow, and ice, are chief contributors to hazardous geophysical flows in nature. A key problem hampering progress in predicting the destructiveness of such hazards is the poorly understood dependence of the flow velocity on the physical properties of the grains constituting a given material. In particular, their usually irregular, non-spherical shapes prevent application of rigorous theories, which were derived for spherical grains. In addition, we do not have a good empirical grasp of the issue, as evidenced by the failure of existing scaling laws across flows of different granular materials when applied to measurements and numerical simulations for idealized flow geometries. Here, we report a scaling law for the steady-state velocity of homogeneous granular flows down rough inclines. It holds for granular materials consisting of irregularly-shaped but relatively uniformly-sized grains descending rough slopes. Laboratory chute experiments and numerical simulations for a diverse range of granular materials corroborate its validity and generality. It exhibits a power-4/3 dependence on the flow thickness, as opposed to the power-3/2 dependence suggested by previous scaling laws. It is also unique in the aspect that it depends only on a single parameter characterizing the granular material: the dynamic angle of repose. This suggests that, quite surprisingly, most of the physical complexity associated with the composition and shape of a material's grains boils down to its bulk ability to resist externally-driven shearing.

How to cite: Pähtz, T.: General scaling law for the velocity of steady, homogeneous granular flows down rough inclines, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9678, https://doi.org/10.5194/egusphere-egu25-9678, 2025.

In steady, fully developed flows over erodible beds, the average bed shear stress is generally the dominant factor governing sediment flowrate. However, fluctuations induced by turbulence can play a significant role in altering sediment transport dynamics. This study investigates the effects of such turbulence by conducting flume experiments with flow disturbances created by various cylinder arrays placed in the flow. To measure the turbulent flow field, Laser Doppler Velocimetry (LDV) was employed, while bed shear stress was quantified using a shear plate. The bedload motion was analysed using Particle Tracking Velocimetry (PTV), which allowed for the quantification of key variables such as sediment concentration, velocity, and sediment flowrate. A descriptive model was developed to capture the relationship between these primary variables and both the average and fluctuating components of the flow. Our results show that with increasing turbulent fluctuations, both sediment concentration and velocity rise at a fixed mean shear stress. Notably, turbulence influences concentration more strongly than velocity.

How to cite: Rebai, D., Koll, K., Radice, A., Aberle, J., and Ballio, F.: Turbulence increases sediment transport, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9842, https://doi.org/10.5194/egusphere-egu25-9842, 2025.

We report on chute measurements of the free-surface velocity $v$ in dense flows of spheres and diverse sands and spheres-sand mixtures down rough inclines. These and previous measurements are inconsistent with standard flow rules, in which the Froude number $v/\sqrt{gh}$ scales linearly with $h/h_s$ or $(\tan\theta/\mu_r)^2h/h_s$, where $\mu_r$ is the dynamic friction coefficient, $h$ the flow thickness, and $h_s(\theta)$ its smallest value that permits a steady, uniform dense flow state at a given inclination angle $\theta$. This is because the characteristic length $L$ a flow needs to fully develop can exceed the chute or travel length $l$ and because neither rule is universal for fully-developed flows across granular materials. We use a dimensional analysis motivated by a recent unification of sediment transport to derive a flow rule that solves both problems in accordance with our and previous measurements: $v=v_\infty[1-\exp(-l/L)]^{1/2}$, with $v_\infty\propto\mu_r^{3/2}\left[(\tan\theta-\mu_r)h\right]^{4/3}$ and $L\propto\mu_r^3\left[(\tan\theta-\mu_r)h\right]^{5/3}h$.

How to cite: Wu, Y., Pähtz, T., Guo, Z., Jing, L., He, Z., and Zhang, J.: Unified flow rule of undeveloped and fully-developed dense granular flows down rough inclines, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10237, https://doi.org/10.5194/egusphere-egu25-10237, 2025.

Progressive slope steepening can trigger episodic dry sand avalanches, resembling landslides commonly observed in natural environments. Similarly, gradual river incision can induce periodic slope instability and failures. To thoroughly investigate the impact of gradual river incision on catchment topography and slope dynamics, we conduct a series of idealized dry sandbox experiments. This simple setup is expected to provide a deeper understanding of the patterns and dynamics of landslides in mountainous regions.

In the experiments, dry sand is removed by applying negative suction pressure through a nozzle traversing prescribed paths over the topography. This process simulates river channel incision into the sand substrate and triggers avalanches on adjacent slopes. The experimental setup consists of a simple box filled with dry sand, equipped with a suction mechanism inspired by the extrusion nozzles used in 3D printing. Unlike 3D printing, where material is added, negative pressure at the nozzle is used to extract material instead.

To validate the system, we first employ a vertically descending suction nozzle at a controlled rate to produce an expanding conical pit. This simple setup allows us to test the suction mechanism and ensure consistent material removal. Subsequently, we simulate river incision by utilizing an idealized curved path designed to mimic the geometry of an incising river. Initially, the nozzle was manually guided along this path to replicate the incision process. In later experiments, a computer-controlled traversing system is implemented to ensure greater precision and reproducibility.

We then explore imposed motions along the main river channel and incorporate tributaries to explore the river incision processes. The results, including the formation of ridges, avalanches, and slope adjustments, are analyzed and compared with computational predictions derived from an eikonal model. This comparison provides valuable insights into the behavior of slopes under conditions of gradual river incision and elucidates the mechanisms driving slope instability and morphological evolution in natural catchments.

How to cite: Chang, E. and Capart, H.: Experimental Analogue Modeling of Slope Dynamics Induced by Gradual River Incision Using a Controlled Suction Nozzle in Dry Sandbox Experiments, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12716, https://doi.org/10.5194/egusphere-egu25-12716, 2025.

We employ data about a dry granular flow down a 19º smooth-walled chute, partially obstructed at the downstream end, to verify the solution of a shallow-water continuum model. The system of conservation equations is based on depth-averaging the ensemble-averaged mass, momentum and fluctuating kinetic energy equations:

(1)  $\partial_t \left(\phi h \right) + \partial_x \left(\phi h u \right) = - \partial_t z_b$

(2)  $\partial_t \left( \rho h u \right) + \partial_{x} \left( \rho h u^2 \right)  = -\partial_{x} \left( \rho g h^2 / 2 \right) - g \rho h \, \partial_{x} z_b  - \tau_b$

(3) $\partial_{t} z_b = - \left( E(x,t) - D(x,t) \right)$

(4) $P = f(\phi) f(e,k,\phi_c) \rho_g T$

(5) $-Q^\prime + \frac{1}{2}\tau_b u/h - \Gamma = 0$

where $x$ is the distance, $t$ is time, the conservative variables are the elevation of the granular bed, $z_b$, the equivalent depth of flowing granular material $\phi h$ and flow momentum $\rho \phi h$, where $\phi$ is the solid fraction, $h$ the granular depth and $u$ the depth-averaged longitudinal velocity, $\tau_b$ is the wall stress, $E$ and $D$ are the rates of particle pick-up and deposition, respectively, $e$ is the normal coefficient of restitution, $k$ is particle stiffness, $\phi_c$ is the critical solid fraction, $\rho_g$ is the density of the solid particles, $\rho = \rho_g \phi$, $\Gamma$ is the rate of dissipation of fluctuating kinetic energy and $Q^\prime$ is the flux of fluctuating kinetic energy at the bottom wall.  The solid fraction is determined from (4) as a function of the granular pressure $P$ (considered hydrostatic) and the granular temperature $T$.

Preliminary results of simulations with borosilicate spheres ( g/cm³ and coefficient of restitution ), with  and  as tuning parameters, indicate that the celerity of the jamming wavefront is well-reproduced. The jump strength and the head losses are not in full agreement, requiring adjustments in the equation of state (4).

Acknowledgements

Portuguese Foundation for Science and Technology (FCT) through the PhD scholarship PD/BD/150693/2020, project PTDC/ECI- EGC/7739/2020 and CERIS funding UIDB/04625/2020.

How to cite: Ferreira, R. M. and Mendes, S.: Shallow-water continuum modelling of dry granular flows in partailly obstructed chutes , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13548, https://doi.org/10.5194/egusphere-egu25-13548, 2025.

The formation and evolution of sediment ribons over a uniform sediment bed in an open-channel flow was investigated via a stereo-photogrammetric system to measure the bed evolution in combination with a stereo-PIV system to measure the three-component velocity field in a cross-sectional plane above the bed. The formation of ribbons is observed to be triggered by the initially meandering low and high-speed streaks sharing the same spanwise wavelength as the fully-developed ribbons.  When the ribbons are fully developed, the streaks are locked in place with low-speed streaks over the ridges and high-speed streaks over the troughs with strong secondary flows.  The lateral stabilization appears to be facilitated by the stable  streaks near the wall.

How to cite: Eiff, O. and Trevisson, M.: Formation and evolution of sediment ribbons in open-channel flow, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13625, https://doi.org/10.5194/egusphere-egu25-13625, 2025.

Landslides in narrow valleys may block adjacent rivers and dam the incoming water flow. The collapse of these landslide dams may lead to catastrophic flooding downstream. The measurement and early warning of dam failures is an important issue in geomorphic processes. However, Optical and radar-based monitoring methods are not suitable for deep internal probing of a dam, which is necessary for dynamic measurement and early warning. In this study, the acceleration of a smart rock in the simulation dam was measured using inertial navigation method. It is found the acceleration response of smart rocks is detected more than 20 seconds before external observations of dam failure. Buried at different positions within a dam, smart rocks exhibit distinct temporal and data form responses to dam failure. Smart rocks located deeper within the dam show multiple acceleration fluctuations before the actual failure occurs. We hope that the measurement data provided by smart rocks will assist in developing multi-scale models of dam failure.

How to cite: Li, R., Li, Y., Mu, T.-T., and Dai, H.: Experimental investigation on the formation and failure of landslide dam using inertial navigation method, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14061, https://doi.org/10.5194/egusphere-egu25-14061, 2025.

Debris flows, as a type of large-scale geological disaster, are a global focus regarding their formation boundary, kinematic properties and deposit morphology. In small-scale laboratory simulations, factors such as water content, equivalent grain size, grain size ratio and aspect ratio significantly influence the formation boundaries and flow regime. Quantifying the effects of these numerous variables is a crucial prerequisite for advancing research on geological disasters represented by debris flows. We conducted simulations of the debris flow triggering process within a horizontal chute and used the proposed centroid vector displacement method to quantitatively assess the kinetic characteristics from an energetic perspective. By integrating the influence of water content into the traditional Bond number, we were able to clearly differentiate three distinct collapse regimes. Through modulation of the size and density ratios, we explored the distribution of intensity for various mechanisms along the flow direction. To characterize the relative strength of diffusion and buoyancy effects on the length scale, we introduced a dimensionless parameter λ. This parameter enabled us to define the boundary conditions necessary for the formation of core-band patterns.

How to cite: Yang, H., Chi, Z., Chen, Q., and Xu, Y.: Energetic kinetic of debris flow in a horizontal chute using centroid vector displacement method, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14133, https://doi.org/10.5194/egusphere-egu25-14133, 2025.

Alluvial fans develop at the base of mountain fronts, where rivers emerge from the constrained mountain area onto the plain. Acting as a transition zone between mountain streams and alluvial rivers, the fan-river system is typically characterized by a slope break in the bed profile, a significant discontinuity in bed surface sediment fining from gravel-sized to sand-sized, and a sudden increase in channel width. In large rivers with great morphological diversity and strong human interference, the shift between upstream and downstream river morphology and sediment dynamics within the alluvial fan-river system exhibits a more complex process. However, this phenomenon remains insufficiently documented and lacks comprehensive analysis.

Here, we take the middle Yangtze alluvial fan as an example and use field observations and numerical modeling to improve the understanding of the large-scale alluvial fan-river system. The result shows that, in contrast to other alluvial fan-river systems, the Yangtze alluvial fan downstream of the Three Gorges Valley had no obvious breaks in the recent bed profile. In addition, the channel width showed an abrupt increase at Zhicheng, followed by a narrowing trend beginning at Chenjiawan. After the Three Gorges Dam (TGD) operation in 2003, the erosive water released from the TGD induced significant erosion, however, the spatial pattern of the bankful width remained stable. The bed profile exhibited increasing variability but continued to lack a distinct slope break; The transition in surface material from gravel to sand was observed throughout approximately 60 kilometers and the location migrated 40 kilometers downstream in the post-TGD period, with gravel and sand patches alternating randomly; Zhicheng and Chenjiawan are two characteristic locations marking the shifts in the mode of sediment transport in the middle Yangtze alluvial fan-river system. For sand transport mode, the reach upstream of Zhicheng had sand transported in suspension, whereas the downstream reaches were dominated by mixed-load transport. For gravel transport mode, gravel from upstream, mostly in the 25–50 mm grain size range, was selectively transported downstream of Zhicheng and deposited at Chenjiawan; The sediment dynamics in the Yangtze alluvial fan-river system were controlled by the width variability and distributary streams. The deposition of fine sand upstream of the gravel smoothed the previously deposited gravel fan profile, resulting in the absence of a slope break in the bed profile. Since 2003, the pattern of the sediment transport mode remained stable despite some local adjustments. This stability is attributed to the stable fan-river morphology induced by the strong resistance of riverbank lithologies and the Jingjiang Great Levee constraints.

How to cite: He, Z., Sun, Z., Li, Y., Luan, H., and Qu, G.: Large-scale alluvial fan-river system of the middle Yangtze River: morphological diversity, grain size discontinuity, and sediment dynamics complexity, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14540, https://doi.org/10.5194/egusphere-egu25-14540, 2025.

Debris flows, prevalent in mountainous regions, exhibit distinct dynamics depending on whether they occur over bedrock (rigid bed) or accumulated deposition (erodible bed). Understanding the transition between these bed types is essential for hazard prediction and mitigation. This study improves an existing unsteady, non-uniform debris flow model to more accurately simulate the evolution of flow depth and velocity under varying boundary conditions. The improved model is grounded in mass, momentum, and kinetic energy conservation principles, incorporating a linearized μ(I) rheology to describe granular flow behavior and Coulomb friction along sidewalls, ensuring a realistic representation of debris flow mechanics.

To validate the improved model, granular dam break experiments were conducted in a narrow glass channel (3.5 m long, 0.04 m wide) with varying downstream deposit depths to establish different basal boundary conditions. High-speed camera footage and Particle Tracking Velocimetry (PTV) were employed to capture granular motion and generate velocity fields. The model exhibited good agreement with experimental results, accurately predicting the flow depth and velocity evolution during the transition between rigid and erodible beds.

Furthermore, the model was applied to field-scale debris flows at the PuTunPunas River in southern Taiwan, a site that has experienced several debris flow events over the past decades. Channel width variations at this site were incorporated into the model to assess erosion potential and flow behavior under real-world conditions. Comparisons with field observations confirmed the model’s capability to simulate debris flow transitions and erosion processes in natural channels, offering valuable insights for hazard assessment and mitigation in mountainous regions.

How to cite: Liao, C.-Y., Tsai, Y.-L., and Hung, C.-Y.: Modeling Debris Flow Transitions: Experimental Validation and Field-Scale Application, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14717, https://doi.org/10.5194/egusphere-egu25-14717, 2025.

Due to various destabilizing factors such as hydro-thermo-mechanical degradation, and earthquakes, the strength of the Earthsurface material may decrease, leading to increased slow earthflow events. Earthflows often cause extensive damage to infrastructure and permanently change the landscape pattern. However, the earthflows have received much less attention compared to their fast-moving counterparts, like avalanches, landslides, and debris flows. Here, we present some novel laboratory experiments simulating slowflows to understand their initiation, movement, and long-term morphological evolution by using a highly viscous material, the molten jaggery, locally found in Kathmandu. The tremendously slowly deforming and moving jaggery is assumed to represent earthflows. Experimental results demonstrate some key aspects of slowflow dynamics of earth materials and seminally contribute to the systematic understanding of earthflow processes. We simulate the slowflow propagation process by using a dynamic earthflow model. Simulation results capture some essential features of the massively viscous, exceptionally slowly deforming, and moving earth surface materials. 

How to cite: Kattel, P., Tiwari, C. N., and Pudasaini, S. P.: Slowflows: Experiments and numerical simulations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14812, https://doi.org/10.5194/egusphere-egu25-14812, 2025.

This study employs remote sensing technology to thoroughly analyse sediment dynamics in expansive aquatic environments, with a specific focus on the Ganga River basin. The investigation spans from 2007 to 2011, utilizing Medium Resolution Imaging Spectrometer (MODIS) MYD09A1.061 Aqua Surface Reflectance 8-Day Global data to assess Suspended Sediment Concentration . By integrating ground-based silt data with satellite data, the study captures temporal variations in suspended sediment levels. The Google Earth Engine (GEE) platform was employed to process sensor imagery and calculate reflectance data, enabling accurate computations for specific time intervals. To further analyse the data, Support Vector Regression (SVR) model was developed. This model analyse changes in reflectance data  to corresponding  observed silt measurements, providing insights into sediment behavior. The results from this model are presented using 2D graphs, highlighting the  effectiveness of remote sensing technology in understanding the sediment dynamics in large river systems. This research offers significant advancements in  methods for monitoring and maintaining water quality in aquatic environments.

How to cite: Bhoopathi, S., Pal, M., and Choubey, H.: Suspended Sediment Concentration Analysis Using Remote Sensing and Machine Learning Approach, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15011, https://doi.org/10.5194/egusphere-egu25-15011, 2025.

Sediment transport in turbulent flows is one of the classical topics in rivers and coastal engineering studies. Due to a lack of general description of interphase interactions, the numerical studies are limited by separately describing the motion of sediment particles in the form of bedload or suspended load depending on the relative importance of particle-particle and particle-turbulence interactions. In this paper, a Reynold-averaged Euler-Lagrange model is developed to study bedload and suspended load simultaneously where the interphase interactions are described in a unified mechanical framework. The inter-particle interactions are resolved and the flow turbulence is described by a modified two-phase k-epsilon turbulence model. Particle-fluid interactions at the volume-averaged scale are characterized by the drag force, the pressure gradient force and the lift force. The effects of the interstitial fluid on particle contacts are taken into consideration by formulations of coefficient of restitution and friction coefficient. A modified Continuous Random Walk (CRW) model is adopted to characterize the stochastic motion of the sediment particles. The effectiveness of the model in describing particle-turbulence and particle-particle interactions is firstly demonstrated by comparison with experiments of sediment transport in bedload and suspended load separately. The model is further applied to the study of sediment transport in sheet flows. Contributions of particle-turbulence and particle-particle interactions to the flow structure, the total transport rate and the rheology of particle-fluid mixtures are analyzed.

How to cite: Li, W.: A general description of interphase interactions in Reynolds-averaged Euler-Lagrange simulations of turbulent sediment transport: from bedload to suspended load, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15155, https://doi.org/10.5194/egusphere-egu25-15155, 2025.

Bedload transport, critical in various natural and engineering systems, involves the complex interaction between particles and flowing water. Predicting bedload transport rates has long been a focal point of interest due to its significance in understanding river dynamics. Pioneering contributions from Einstein and Bagnold have led to substantial progress in this field derived from extensive laboratory and in-situ observations, which are yet to achieve the desired accuracy when validated against real-world hydrological data. The discrepancies in predictions can partly be attributed to the difficulties in accurately capturing the movements of near-bed particles and the flow field characteristics.

This paper presents a numerical investigation via Computational Fluid Dynamics-Discrete Element Method into detailed observations on particle movements and flow characteristics of bedload transport. It provides a thorough review of the assumptions and theories prevalent in current bedload models. Simulations have been conducted covering flow velocities ranging from below the generally accepted critical Shields number to the onset of bedform formation. We analyze particle trajectories and statistical behaviors under various conditions, focusing on both the motions of individual particles and the collective evolution of bedforms, and our primary results include: 1. The incipient motion of particles is a gradual process that can occur before reaching the generally accepted critical Shields number. 2. The emergence and development of bedforms under varying conditions. 3. Observations on the relationship between particle movement characteristics and the shear conditions. These findings enhance our understanding of particle-scale dynamics in bedload transport, providing a foundation for evaluating and improving existing models for predicting transport rates.

How to cite: Li, X., Zhao, T., and Xu, B.:  Flow Characteristics and Particle Kinematics in Bedload Transport: a CFD-DEM investigation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15234, https://doi.org/10.5194/egusphere-egu25-15234, 2025.

Assessing particle-scale interactions and transport phenomena is essential yet complex within geophysical flows found in both natural and artificial settings. This research introduces the design, validation, and calibration of a spherical inertial sensor particle meticulously engineered to achieve full kinematic equivalence with a solid sphere. By employing Micro-Electro-Mechanical Systems Inertial Measurement Unit (MEMS-IMU) technology, this low cost 40 mm particle can measure triaxial acceleration up to ±16g and triaxial angular velocity up to ±2000°/s, operating at a high sampling rate of 1000 Hz over a duration of one hour. The sensor particle possesses a dual-layered spherical configuration deliberately crafted to ensure alignment in shape, density, center of mass, moment of inertia, and elastic modulus with that of a solid sphere. Its performance is rigorously assessed, validated, and calibrated through a series of physical experiments. Furthermore, a data enhancement technique grounded in lubrication theory is invented to mitigate technical challenges associated with accelerometer saturation and temporal resolution. This method enables our sensor particle to accurately capture particle collision processes within liquid environment, which proves challenging with conventional approaches. This investigation offers a foundational instrument for large-scale particle motion studies, such as those related to debris flows, facilitating, for the first time, the precise measurement of the dynamic behavior of individual particles within a substantial ensemble.

How to cite: An, Y., Jiao, J., and Zhang, L.: Spherical Inertial Sensor for Measuring Particle-Scale Interactions in Geomorphic Flows with Full Kinematic Equivalence, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15433, https://doi.org/10.5194/egusphere-egu25-15433, 2025.

We have investigated the modeling of collisional bed-load transport with a focus on continuum approaches for granular flow. A frictional-collisional framework, combining the Coulomb model and the kinetic theory of granular flows, is proposed to address the limitations of classical kinetic theory, which fails to accurately reproduce results from coupled fluid–discrete simulations. These discrepancies are attributed to assumptions of negligible interparticle friction and the absence of a saltation model in continuum formulations. 

To guide model development, the fluctuating energy balance obtained from discrete simulations is systematically compared with kinetic theory predictions. The analysis reveals that interparticle friction significantly affects the radial distribution function and increases energy dissipation, aligning with previous findings. Additionally, a saltation regime is identified, causing deviations from the viscosity and pseudo-thermal diffusivity laws of kinetic theory in dilute regimes. 

Building on these insights, the two-fluid model is modified to incorporate interparticle friction and coupled with a saltation model. The results demonstrate that for inelastic, frictional particles, interparticle friction primarily governs energy dissipation, and the macroscopic granular flow behavior is independent of microscopic particle properties. The enhanced model successfully reproduces the 𝜇(𝐼) rheology in the dense regime of granular flow. Experimental validation confirms significant improvements in predicting granular flow behavior, highlighting the model’s effectiveness in capturing key physical processes. 

How to cite: Chauchat, J., Chassagne, R., and Bonamy, C.: A Continuum Framework for Modeling Frictional-Collisional Interactions in Bed-Load Transport: Insights from Discrete Element Simulations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16152, https://doi.org/10.5194/egusphere-egu25-16152, 2025.

Non-hydrostatic dispersive models can better describe the landslide motion. Following a dispersive wave equation and a mechanical erosion model for mass flows, here, we develop a novel dynamically coupled dispersion-erosion wave model that combines these two very essential complex processes. The newly developed model for landslide recovers the classical dispersive water waves and dispersive wave equation for landslide as special cases. We present several exact analytical solutions for the coupled dispersion-erosion model. These solutions are constructed for the time and spatial evolution of the flow depth. Solutions reveal that the dispersion and erosion are strongly coupled as they synchronously control the landslide dynamics. The results show that the wave dispersive wave amplifies with the increasing particle concentration, decreasing earth pressure, higher gravitational acceleration, increased slope angle and increased basal friction. The important novel understanding is that the intensity of the dispersive wave increases when erosion and dispersion are coupled. The results indicate the essence of proper selection of the initial and boundary conditions while solving applied and engineering problems associated with the dispersive - erosive mass transport. This provides the foundation for our understanding of the complex dispersion and erosion processes and their interplay.

How to cite: Kafle, J., Dangol, B. R., and Pudasaini, S. P.: Dispersion - Erosion Coupling in Landslides, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17293, https://doi.org/10.5194/egusphere-egu25-17293, 2025.

Dunes are ubiquitous in river, marine, desert and Martian environments. The flow of fluid 
over mobile bed results in evolution of dunes of different sizes and shapes. The shape of dune 
has critical role in sediment transport and interacting with flow. Earlier studies assumed the 
dune shape as a triangle (2-Dimensional) to study the flow field over dunes. However, dunes 
are highly three dimensional and their 3D patterns can increase the form drag compared with 
equivalent 2D dunes in similar flows. Pearson correlation, 2D spatial correlations are used to 
describe three dimensionality of dune in previous studies. A robust methodology to quantify 
3D bed forms and linking it to the flow needs to be developed. In this study, experiments are 
conducted to form 3D dunes on plane bed with non-uniform fine sand (d50 = 0.395 mm, σg = 
1.56) under sub critical flow conditions. The bed morphology is continuously monitored 
using ultrasonic ranging probes (URS) placed 5 cm c/c distance in 1 m wide flume. 
Experiments are performed till equilibrium state is achieved and continued further (2 hrs) to 
observe the bed changes. The equilibrium bed is measured at 2 cm resolution with a laser 
distance meter. The 3D velocity components and suspended sediment concentration are 
continuously measured using down looking Accoustic Doppler Velocimeter (25 Hz). Signal 
processing techniques are used to remove outliers, to smoothen the local fluctuations and 
identification of dune crest and troughs. In addition to 2D correlation and Pearson correlation 
coefficient, Fractal dimensions and topological metrics are also used to asses three 
dimensionality of the sediment bed. Roughness of the sediment bed is quantified using 
standard deviation of bed elevation. From the experiments, it was observed that three 
dimensionality is reduced with an increase in discharge. The spatial data is transformed into 
frequency domain. Periodicity of the process is analyzed from harmonics and spatially 
averaged spectrums. The height and length of dunes is modelled using exponential fits and 
observed a nonlinear growth of dunes. The flow measurements showed that the flow velocity 
in lobe region and turbulent kinetic energy in saddle region are increased. The mean sediment 
flux in the flow direction is directly proportional to the depth. Whereas, the turbulent fluxes 
exhibit an increasing trend up to 0.36–0.38 times the flow depth and then decrease with 
further increases in flow depth.

How to cite: Bodapati, S. S. P. and Chandra, V.: The Fractal and Topological Metrics for Assessing Three-Dimensionality in Dune Morphology , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18148, https://doi.org/10.5194/egusphere-egu25-18148, 2025.

Understanding the morphodynamics of tidal dunes is essential for improving predictions of sediment transport and seabed evolution in coastal and estuarine environments. This study advances our understanding through a combined experimental and numerical investigation into the short-term morphodynamic evolution of laboratory-scale tidal dunes under controlled conditions.

Building on earlier flume experiments examining hydrodynamic interactions of reversing currents with fixed-bottom, sand-coated asymmetric compound dunes, we incorporated a cm-thick layer of unimodal sediment over the rigid dune models to simulate mobile-bed conditions. High-resolution Particle Image Velocimetry (PIV) was employed to capture detailed spatial and temporal dynamics of turbulent flows and the concurrent evolution of dune surfaces.

Complementary numerical modelling utilised the oceanographic circulation model CROCO, incorporating its non-hydrostatic solver and the USGS sediment transport module. The lab-scale model application was calibrated and validated against the laboratory measurements, demonstrating exceptional agreement in the short-term evolution of dune morphology. Key findings include the accurate replication of observed boundary layer dynamics, sediment transport mechanisms, and morphodynamic changes under reversing tidal currents. These experiments establish a solid benchmark for validating non-hydrostatic models of tidal dune morphodynamics.

This work underscores the transformative potential of integrating detailed physical experiments with advanced numerical models to refine our predictive capabilities for morphodynamic processes in tidal environments. The insights gained are particularly significant for coastal engineering and seabed mobility studies, with direct applications to the design and optimisation of offshore wind farm infrastructures.

How to cite: Porcile, G., Mouazé, D., Weill, P., Gangloff, A., and Bennis, A.-C.: Quantifying Tidal Dune Morphodynamics at the Laboratory Scale: A Combined Measuring and Modelling Approach, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19135, https://doi.org/10.5194/egusphere-egu25-19135, 2025.

We investigate the submerged cohesive collapse of cohesive granular columns, as a function of packing densities and cohesive force strength, via grain-resolving direct numerical simulations. We not only obtain the randomly packed granular columns but also the regular densely packed columns by Hexagonal close-packed (HCP) structure. The cohesive forces act to reduce the final runout distance of the collapsing column, which will no longer collapse when the cohesive force is larger than a critical value. This critical value decreases with the increase of the packing density. The cohesive forces significantly accelerate the contraction for loosely packed columns and decelerate the dilation for densely packed columns, resulting in a larger positive excess pore pressure and a smaller negative excess pore pressure, respectively. The collapsing column has distinct straight-like failure surfaces at the initial time, whose angle with the horizontal plane increases with the packing density. The force-chain network analysis indicates that the strong cohesive force chains form more easily in the failure region and have a larger size with increasing the cohesive force and packing density, which induces a larger macroscopic cohesive resistance. The cohesive force has a canceling effect on the normal contact force, which results in a smaller size for the contact force chains.

How to cite: Zhu, R., He, Z., and Meiburg, E.: Submerged granular collapse: different cohesion strength and initial packing densities, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20382, https://doi.org/10.5194/egusphere-egu25-20382, 2025.

We investigate the characteristics of low-temperature yellow stimulated luminescence (YSL), to compare its utility for dating with infrared stimulated luminescence (IRSL) stimulated at 50 °C (IR₅₀), post-IR₅₀ yellow stimulated luminescence (pIR-YSL) and pIRIR₂₉₀. Altogether, eleven samples from a range of depositional environments and known ages were tested. Thermal stability, bleachability, dose recovery, fading tests and equivalent dose estimation were undertaken. The pIR-YSL signal is stable up to 150 °C but susceptible to thermal transfer at higher temperatures and both the pIR-YSL and YSL₅₀ signals bleach out at a rate and extent that is similar to the IR₅₀ signal. Dose recovery tests on four of the young intermediate samples illustrate that the pIR-YSL signal can be both recovered and fully reset. Fading tests show that all three signals suffer from significant fading and equivalent dose estimations of the saturated samples IR₅₀, IR-YSL and YSL₅₀ signals significantly underestimate relative to the pIRIR₂₉₀ signal. Elevated temperature signal combinations are additionally evaluated with the aim of further understanding the effect of elevated temperatures on the fading rate and ultimately the utility of YSL signals for dating.

How to cite: Buchanan, G., Preusser, F., Fitzsimmons, K., and Lauer, T.: Progress exploring the characteristics of yellow stimulated luminescence on potassium feldspar , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-646, https://doi.org/10.5194/egusphere-egu25-646, 2025.

The sedimentary units overlying the so-called ‘Falaise de la Mine d'Or’ on the South-East coast of Brittany (France) have been studied for decades to reconstruct the evolution of fossil fluvial valleys in Brittany during the Pliocene and Quaternary (Guillocheau et al., 1998; Menier et al., 2006). However, published numerical ages are insufficient to provide a precise age of each of the units described, whose chronology relies on correlations with ESR dating of fluvial sediments from the interior of Central Brittany (Laurent et al., 1996). Thanks to the cron-BRET Project of the MSCA-Bienvenüe Bretagne Programme carried out by the Geo-Ocean Laboratory of the Université de Bretagne Sud in collaboration with the Cosmogenic Nuclide Laboratory of the University of Cologne (Germany), it has been possible to date the lower unit (U1), mainly composed of quartzite gravels and pebbles. In situ ¹⁰Be and ²⁶Al concentrations produced within the quartz of these clasts become controlled by differential rates of decay when shielded from production at the surface (Dunai, 2010). The fact that the sediments are buried under a sedimentary shield of more than three metres, allows for the calculation of a burial age from the concentration of ¹⁰Be and ²⁶Al by using the isochron method (Balco and Rovey, 2008; Granger et al., 2022). Preliminary results provide numerical data that place the formation of this unit 2.72 ± 0.19 million years ago, at the Plio-Quaternary boundary. Our study also includes the dating of the upper unit (U3) mainly composed of sand-sized materials (90-2000 µm), by analysis of the optically stimulated luminescence (OSL) signal of quartz (Murray et al., 2021) at the RenDaL Luminescence Laboratory (Géosciences- Univ. Rennes). The calculation of the palaeodose using Bayesian procedures (BayLum; Philippe et al., 2019) and of the natural dose rate from high-resolution gamma spectrometry (HRGs) measurements provides a burial age range between 263 and 408 ky. These data will be complemented by the dating of the materials composing unit U2 by analysing the infrared stimulated luminescence signal (IRSL) of potassium feldspar to extend the available dates and the knowledge of the landscape evolution of this coastal area linked to glacioeustatic oscillations and neotectonics during the Pleistocene.

How to cite: Arce Chamorro, C., Sautter, B., Guérin, G., Guillocheau, F., Binnie, S., Dunai, T., and Menier, D.: Optically Stimulated Luminescence and in situ 10Be / 26Al cosmogenic dating of the Upper and Lower Units from ‘La Falaise de la Mine d'Or’ at Pénestin (SW Brittany, France) within the cron-BRET Project., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1384, https://doi.org/10.5194/egusphere-egu25-1384, 2025.

Lake sediments form a valuable and often continuous record for reconstructing past climate and the occurrence and impact of natural hazards. The interpretation of this record, however, relies heavily on a robust chronology formed by age-dating the sediments. For recent (i.e. Quaternary) lake sediments, radiocarbon dating of organic material is a fundamental dating technique. However, constructing a lake sediment chronology can be challenging, since the use of radiocarbon dating is dependent on many factors, including the type of material to be dated, depositional circumstances and possible contamination of ¹⁴C. Volcanogenic CO₂, for instance, is depleted in ¹⁴C. This implies that in regions with surface exhalations of volcanic CO₂ the concentration of ¹⁴C in the surrounding atmosphere is diluted. For this study, the effect of volcanogenic CO₂ gas emissions on the use of radiocarbon dating was investigated in the Laacher See volcanic crater in western Germany. This crater was formed after the eruption of the Laacher See Volcano around 13 ka BP. It contains multiple degassing vents emitting CO₂ of magmatic origin, in the form of underwater bubble seeps in the lake (“wet mofettes”) and onshore soil degassing (“dry mofettes”). Living plant material, i.e. leaves of Taraxacum genus plants, were sampled in several locations in the crater and dated to examine their range in radiocarbon ages and spatial variability. Additionally, a > 4 m long sediment core taken in the lake was sampled for organic material and bulk sediment to assess the offset of radiocarbon ages to their true or expected ages. Our results show that all dated samples exceed their true or expected ages, with the Taraxacum samples giving variable radiocarbon ages of up to 9000 a BP. Along a transect of sampled Taraxacum plants, the radiocarbon ages decrease with an increasing distance from the degassing vents along the lake shore. The radiocarbon ages of the sediment core samples show that organic material deposited in the lake is also affected by volcanogenic CO₂ emissions, with some radiocarbon ages exceeding the age of the Laacher See eruption that formed the crater, although no regular offset could be determined for these samples with regard to their depth in the core. Furthermore, the radiocarbon ages do not correspond to a ²¹⁰Pb/¹³⁷Cs age-depth model that was established for the top of the core. Radiocarbon dating is shown to not provide reliable results for establishing a chronology for the sedimentary infill of Laacher See. Further research is required to better understand the influence of volcanogenic CO₂ on organic material, such as effects of temporal and spatial variations in CO₂ flux. In the case of Laacher See, other age-dating techniques should be considered to establish an age-depth model with reliable, non-¹⁴C dependent ages.

How to cite: Claeys, L., Albers, S., Hajdas, I., and De Batist, M.: Volcanogenic CO2 emissions affect radiocarbon dating in a case study from the Laacher See crater lake, Germany, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1725, https://doi.org/10.5194/egusphere-egu25-1725, 2025.

This study details the construction of an age-depth model for the uppermost 128 meters of the 600 m long Acıgöl2009-B03 sediment core, retrieved from hypersaline Lake Acıgöl in southwestern Anatolia. The model matches the arboreal pollen record from Acıgöl2009-B03 with the LR04 benthic δ18O stack marine oxygen isotope record. Initial correlation employs the Dynamic Time Warping algorithm, refined through manual tuning. Validation of the model's accuracy incorporates multiple chronological constraints, including three radiocarbon dates, three U/Th dates, and the Kos Plateau Tuff, dated at 161.3 ± 0.1 ka. According to this model, the upper 128 meters of the Acıgöl2009-B03 sequence spans approximately the last 487,000 years, encompassing Marine Isotope Stages (MIS) 1 to 12 and part of MIS 13. Our model serves as an update to the previously published, linearly constructed, age model as being used more anchor point and an efficient algorithm for similarity measurements which lies on a robust statistical foundation. In this period, arboreal pollen data suggest increasing (decreasing) arboreal vegetation input during interglacial (glacial) periods.

How to cite: Çaldırak, H., Ön, Z. B., Akkiraz, S., Çağatay, M. N., Ghaleb, B., Wulf, S., Eriş, K. K., Acar, D., Kaiser, J., and Akçer Ön, S.: Chronology and environmental changes from a sediment core spanning the last 487 kafrom Lake Acıgöl (SW Anatolia), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1998, https://doi.org/10.5194/egusphere-egu25-1998, 2025.

Luminescence dating has long been used for dating sediments both in geological as well as archaeological context. Following numerous advances in feldspar and quartz luminescence dating in recent decades, a new method for feldspar dating is currently under development: Infrared photoluminescence (IRPL) is a novel technique, which allows the direct and non-destructive measurement of luminescence emitted by trapped electrons in feldspars (Prasad et al., 2017). IRPL arises from radiative excited state to ground state relaxation of trapped electrons within the principal trap in feldspar.

IRPL measurements enable the investigation of two emissions, one at 880 nm and another one at 955 nm (Kumar et al., 2018, 2021). Whilst most research on IRPL has focussed on understanding the physical processes leading to the IRPL emission in feldspars, yet little is known with regard to the application of IRPL as a dating technique. We build upon a first measurement protocol for sediment dating developed by Kumar et al. (2021) and combine the IRPL measurements with a modified post-IR IRSL protocol (pIRIR₂₂₅ with IR stimulation at 50°C, 90°C, 225°C), which allows a comparison of the IRPL signals with three IRSL signals. This integration of the IRPL measurements in a pIRIR protocol might possibly reduce fading to a negligible level due to the successive IRSL and IRPL measurement steps.

First promising results on loess samples with known (independent) age from the Balta Alba Kurgan loess-paleosol sequence in Romania (Scheidt et al., 2021) will be presented. We conducted dose recovery tests, bleaching experiments and equivalent dose measurements using different test doses and will show first results of fading measurements. The dose recovery tests are within 10% of unity for most of the measurements suggesting sufficient performance of our novel IRPL/pIRIR protocol. However, IRPL equivalent doses seem to slightly underestimate previously measured pIRIR₂₉₀ equivalent doses. Possible reasons will be discussed within the EGU presentation.

References

Kumar, R., Kook, M., Murray, A.S. & Jain, M. (2021). Towards direct measurement of electrons in metastable states in K-feldspar: Do infrared-photoluminescence and radioluminescence probe the same trap? Radiation Measurements 120, P. 7-13.

Kumar, R., Kook, M., & Jain, M. (2021). Sediment dating using infrared photoluminescence. Quaternary Geochronology 62, 101147.

Prasad, A.K., Poolton, N.R.J., Kook, M. et al. (2017) Optical dating in a new light: A direct, non-destructive probe of trapped electrons. Sci Rep 7, 12097.

Scheidt, S., Berg, S., Hambach, U., Klasen, N., Pötter, S., Stolz, A., ... & Nett, J. J. (2021). Chronological assessment of the Balta Alba Kurgan loess-paleosol section (Romania)–a comparative study on different dating methods for a robust and precise age model. Frontiers in Earth Science, 8, 598448.

How to cite: Nett, J. J., Reimann, T., and Riedesel, S.: Luminescence dating of feldspar using a novel infra-red photoluminescence signal – first dating results from loess samples, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2273, https://doi.org/10.5194/egusphere-egu25-2273, 2025.

How to cite: Cui, F., Zhang, H., Liu, J., and Qin, J.: Rock Luminescence Dating Method for Studying the Temporal and Spatial Evolution of the Maying River, Qilian Mountains, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3717, https://doi.org/10.5194/egusphere-egu25-3717, 2025.

Dikes are among the most significant ancient human-made earthworks for flood control, land reclamation, and water management for millennia. However, determining the age of dike construction and development based on traditional dating methods (e.g., historical documents, archaeological find materials, and radiocarbon dating), is challenging, due to the paucity of materials and historical records. Luminescence dating may provide an alternative as it uses ubiquitous quartz or feldspar minerals to directly determine the burial age of sediments. In this study, we applied quartz optically stimulated luminescence (OSL) and feldspar single-grain post-infrared infrared stimulated luminescence (pIRIR) dating on two dikes: the Waal dike (near Wolferen-Sprok) in the Netherlands and the Scheldt dike (near Bornem) in Belgium. Our results confirm that luminescence dating provides reliable age estimates, consistent with other independent proxy data such as radiocarbon dating, archaeological artifacts, and historical evidence, and may refine site chronologies. Based on the age results, the history of dike construction and evolution was reconstructed. Additionally, the well-reset OSL signals for dike-related sediments suggest that fresh flood deposits were used for construction. This study highlights the potential of luminescence dating as a robust tool for reconstructing the history of dike construction and understanding ancient engineering.

How to cite: Huang, C., van Beek, R., Chamberlain, E., Wallinga, J., Moree, J., Cruz, F., Laloo, P., and Norde, E.: Reconstructing dike history using luminescence dating, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4772, https://doi.org/10.5194/egusphere-egu25-4772, 2025.

We use in-situ cosmogenic 10Be in an attempt to date the construction of the Kalasasaya Platform temple at the UNESCO Heritage archaeological site at the ancient city of Tiwanaku, Bolivia. The unique site is located within the altiplano valley of Tiwanaku at 3870 masl near the southern shores of Lake Titicaca. The monuments at Tiwanaku were constructed as ceremonial and civic buildings of exceptional precision and quality by an Andean civilization, who were precursors of the Inca Empire. The date of construction of Tiwanaku is unknown. Earliest settlement is believed to be at least ~3,000 years ago and archeological evidence supports a drought-based empire collapse in the first half of the 12th century. Radiocarbon dating of construction material and other debris range from 300 to 950 AD (ie 1700 to 1050 years ago). At its apogee Tiwanaku is estimated to have extended over an area of as much as 6km2 and to have housed between 70,000 and 125,000 inhabitants.We gained permission to sample the very tops of 3 of the Kalasasaya pillars, and multi-meter sized excavated sandstone blocks and adjacent unmodified bedrock outcrop at a known quarry site which was used for sourcing material for Tiwanaku construction.  The pillars, ~5 meters tall and of square meter section, frame the outer perimeter wall of the 120m square Kalasasaya Platform and are made of andesite and sandstone. Samples at the quarry site, about 15 km distant and at 4300 masl,   were taken from  surfaces of the cavity from where blocks originated, select faces from the extracted blocks and  unmodified  bedrock outcrop. We were able to re-orient extracted blocks back into their original excavated cavity and thus determine pre-excavated buried and post-excavated exposed faces which allowed us to measure how long ago the block was carved out of bedrock and rotated in the process. Our results show that the cosmogenic signal in platform pillar tops is dominated by inheritance but that blocks had been quarried as recently as 1500-3000 tears ago, the age range depending on choice of attenuation length and estimating shielding. Details of sampling, site descriptions and 10Be-age calculations will be presented.

How to cite: Fink, D., Levchenko, V., and Fujioka, T.: Cosmogenic exposure dating the Pre-Columbian archaeological structures at Tiwanaku, Bolivia , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5262, https://doi.org/10.5194/egusphere-egu25-5262, 2025.

U-Th geochronology is a key tool in Quaternary geology, widely applied to carbonate matrices with significant advancements achieved through MC-ICP-MS technology. However, ²³⁰Th dating remains challenging for samples with low-uranium concentrations and high-detrital thorium content which often reflecting open-system behavior. These factors increase uncertainties in age calculations. This study introduces an optimized U-Th dating methodology that integrates refined wet chemistry protocols and 10¹³-ohm amplifiers, significantly reducing expanded uncertainties.

The study employs a four-step validation process: i) testing 10¹³-ohm amplifiers using the NBL U-reference material (CRM 112A), and Th-reference material (IRMM035) of IRMM, ii) application to low-U (10–15 ppb) speleothem samples from the Cueva Fantasma (Atapuerca paleontological-archeological site, Burgos, Spain), iii) analysis of open-system shell samples from Turkey, iv) analysis of the internal speleothem standard (BSS2) of CENIEH.

Initial results using CRM 112A and IRMM035 reveal a tenfold improvement in signal-to-noise ratios with the 10¹³-ohm amplifiers. This configuration enables the use of Faraday cups instead of SEM detectors for U and Th-standard analyses, even at very low intensities (0.002–0.007V), a critical improvement for minimizing uncertainty budgets during bracketing sequences in U-Th dating. Comparative analyses of real samples from Atapuerca, Turkey, and the CENIEH speleothem standard (BSS2) show that the refined methodology reduces U-Th age uncertainties from 2–3% to 0.5–1%.

Beyond improved precision for younger, low-U samples, the method reduces the required sample size from ~100-150 mg to 40–50 mg, substantially lowering the influence of detrital Th contamination. The broader significance of this optimized approach lies in its application to environmental reconstruction during the Quaternary, offering robust tools for deciphering climate archives, paleoenvironments, and archaeological contexts.

How to cite: Hasözbek, A., Pourmand, A., Sharifi, A., Isabel Ortega, A., Parés Casanova, J., Vallverdú Poch, J., and Constantin, S.: Optimized U-Th Chronometry for Carbonates Using MC-ICP-MS: Advancements in Precision and Applications, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6277, https://doi.org/10.5194/egusphere-egu25-6277, 2025.

Past climate and environmental changes can be reconstructed using paleoclimate archives such as ice cores, lake and marine sediment cores, speleothems, tree rings and corals. The dating of these natural archives is crucial for deciphering the temporal sequence of events and rates of change during past climate changes. It is also essential to provide quantified estimates of the absolute and relative errors associated with the inferred chronologies. However, this task is complex since it involves combining different dating approaches at different paleoclimatic sites and often on different types of archives. Here we present Paleochrono-1.1, a new probabilistic model to derive a common and optimised chronology for several paleoclimatic sites with potentially different types of archives. Paleochrono-1.1 is based on the inversion of an archiving model: a varying deposition rate (also named growth rate, sedimentation rate or accumulation rate) and also, for ice cores, a lock-in-depth of air (since, in the absence of significant surface melt, the air is trapped in the ice at about 50-120 m below the surface) and a thinning function (since glacier ice undergoes flow). Paleochrono-1.1 integrates several types of chronological information: prior knowledge of the archiving process, independently dated horizons, depth intervals of known duration, undated stratigraphic links between records, and, for ice cores, Δdepth observations (depth differences between events recorded synchronously in the gas and solid phases of a certain core). The optimization is formulated as a least-squares problem, assuming that all probability densities are near-Gaussian and that the model is nearly linear in the vicinity of the best solution. Paleochrono-1.1 is the successor of IceChrono, which produces common and optimized chronologies for ice-cores. Paleochrono-1.1 outperforms IceChrono in terms of computational efficiency, ease of use, and accuracy. We demonstrate the ability of Paleochrono-1.1 in an experiment involving only the MSL speleothem in Hulu Cave (China) and compare the resulting age model with the SISALv2 age models. We then demonstrate the multi-archive capabilities of Paleochrono in a new ice-core–speleothem dating experiment, which  combines the Antarctic Ice Core Chronology 2023 dating experiment, based on records from five polar ice cores, with data from two speleothems from Hulu Cave dated using uranium/thorium radiometric techniques. We analyse the performance of Paleochrono-1.1 in terms of computing time and memory usage in various dating experiments. Paleochrono-1.1 is freely available under the MIT open-source license.

How to cite: Parrenin, F., Marie, B., Christo, B., Emilie, C., Ellen, C., Drysdale, R., Kawamura, K., Landais, A., Mulvaney, R., Oyabu, I., and Rasmussen, S.: The Paleochrono-1.1 probabilistic model to derive a common age model for several paleoclimatic sites using absolute and relative dating constraints, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6728, https://doi.org/10.5194/egusphere-egu25-6728, 2025.

While highly desired, it remains a challenge for luminescence dating to determine high doses, hence high ages (e.g., >300 ka). The challenge is to project a natural dose close to saturation to a dose-response curve generated with high laboratory doses. The single saturating exponential (SSE) function mostly delivers poor fits to this type of dose responses. Other functions, e.g., the single saturating exponential plus linear function, are then often employed, but these include constants that have no direct physical meaning. Such an approach is inconsistent with the OSL/IRSL measurement parameters (e.g. detection wavelength) by which the signal from a dosimeter’s specific trap-hole pair is targeted out of a broad light spectrum. It is therefore beneficial to employ a physically based model that allows to interpret observations obtained from high laboratory dose responses.

Here we employ the analytical expression, Lambert W, developed by Pagonis et al. (2020) which is an exact solution of the well-studied OTOR (one trap one recombination centre) model, and extended by Lawless and Timar-Gabor (2024) to the OTORX model. We compare results obtained from SSE fits, in particular the characteristic saturation dose (“D₀”) parameter, with those obtained from the OTOR(X) functions. Well-bleached fine-grained polymineral samples irradiated up to ~5000 Gy were used and measured using the pIRIR₂₂₅ protocol.

For the SSE function the results point to the 80% rule of thumb: at ca 80% of the saturation dose the SSE-fitted dose response tend to underestimate the natural dose. The OTOR(X) functions reveal that this is due to the ratio of trapping rate versus recombination rate of free electrons which changes as the regenerated dose response approaches saturation. Consequently, the shape of the dose response curve flattens out in a way that the SSE function is unable to predict. We show here how the change of shape affects the dose interpolation point and how the accuracy of dose estimate is tested using the 63% (D₀) and 80% dose values. We conclude that the OTOR(X) functions provide accurate estimates of natural doses close to saturation.

How to cite: Mauz, B., Kreutzer, S., and Lawless, J. L.: Using OTOR(X) fit functions to improve estimation of high natural luminescence doses, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8761, https://doi.org/10.5194/egusphere-egu25-8761, 2025.

The chronology of Late Glacial and Early Holocene dune formation and wildfire activity at the Łaskarzew site, eastern Poland, was established using AMS radiocarbon (¹⁴C) and optically stimulated luminescence (OSL) dating. Situated within the European Sand Belt, the profile preserves 13 aeolian-soil cycles characterised by alternating phases of aeolian deposition, soil formation, and wildfire episodes, demonstrating the dynamic response of aeolian systems to short-term climatic oscillations. A total of 26 charcoal samples, collected from palaeosols and charcoal layers, were radiocarbon-dated, and cross-referenced with OSL ages of quartz grains, resulting in a robust chronological framework. Dune formation began during the Oldest Dryas, with intensified aeolian activity and four wildfire events recorded during the Allerød interstadial, a period marked by rapid vegetation regeneration and recurring fire episodes. The absence of Younger Dryas sediments reflects extreme environmental conditions, including aridity, limited vegetation, and intensified aeolian erosion. The Holocene sequence, enriched with charcoal-rich deposits, records nine independent wildfire episodes over approximately 4500 years, linked to warm climatic conditions that favoured the expansion of fire-prone pine forests and shaped dune environments. Aeolian activity persisted through this period, accumulating approximately three metres of sediment, before ceasing around 7 ka BP as vegetation stabilised the landscape. The integration of radiocarbon and luminescence dating techniques provided a detailed Late Quaternary chronology, offering valuable insights into the interplay of fire, vegetation, and aeolian processes within the European Sand Belt.

How to cite: Piotrowska, N., Moska, P., Sokołowski, R. J., Poręba, G., Zieliński, P., Mroczek, P., Łopuch, M., Jary, Z., Ustrzycka, A., Wojtalak, A., Szymak, A., Tudyka, K., Raczyk, J., Krawczyk, M., Adamiec, G., and Skurzyński, J.: Reconstructing Late Glacial–Early Holocene dune formation and wildfire dynamics using radiocarbon and OSL dating: Łaskarzew, Poland, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12582, https://doi.org/10.5194/egusphere-egu25-12582, 2025.

The Middle Palaeolithic site of Chez-Pinaud in Jonzac (SW France) provides an unparalleled insight into the hunting and butchering behaviour of Neanderthals from ~60 ka ¹ ago. Excavations in the late 1990’s and early 2000’s uncovered a 6-meter sedimentary sequence comprising apparently alternating thin sterile layers and artefact-rich deposits, hosting densely packed accumulations of large ungulate bone fragments and lithics of the Quina Mousterian industry ² . These periodic deposits suggest repeated occupation and abandonment of the site, where Neanderthals were not inhabiting for long periods.  Despite these observations we are still limited in a obtaining a full occupational history of the site, predominantly due to limitations in existing dating methods.

In this study a novel sampling approach was applied to improve the chronological resolution of this site, combining high-resolution Optically stimulated luminescence (OSL) dating and Bayesian modelling. A 40 x 40 x 40 cm sediment block was removed from the main Quina-bearing layer (Layer 22 ²). Under controlled orange light at the RenDaL OSL laboratory at Université de Rennes, the block was carefully excavated by scraping away sediment in horizontal layers. Coordinates of artefacts were recorded and samples for OSL dating were collected at ~1 cm intervals down the block.  Single-grain quartz OSL data were analysed using the BayLum R package ³, incorporating Bayesian statistical modelling to reduce age uncertainties and to investigate the models capacity to handle OSL ages in close temporal and spatial distribution.

Our results indicate that the top of the section represents more modern deposits (~2 ka), which are void of bone fragments. These ages suggest sediment mixing from surface disturbances such as collapsing limestone or anthropogenic activities. Beyond this modern layer, two artefact-rich occupational layers separated by a thin sterile layer are identified through plotting the 3D distribution of the artefacts. The corresponding Bayesian ages for these layers vary between 58 – 80 ka, and do not increase linearly with depth and are thus difficult to correlate directly with the individual artefact bearing layers. These varying ages raise questions over dose rates when we consider the complexity of the heterogeneous sediments in the block. Continuing modelling will be conducted with BayLum as well as further investigation into the dose rate of the samples in attempts to further investigate and increase precision of the ages.

This work underscores the value of combining precise excavation methods with Bayesian analytical approaches for OSL data to construct precise chronologies, especially in important prehistoric archaeological contexts which host well preserved and challenging chronologies.

References:

¹ Richter, D. et al. Thermoluminescence dates for the Middle Palaeolithic site of Chez-Pinaud Jonzac (France). Journal of Archaeological Science 40, 1176–1185 (2013).

² Airvaux, J. & Soressi, M. Le site paléolithique de chez-Pinaud à Jonzac, Charente-Maritime. Prehistoire du Sud-Ouest 8, (2004).

³ Philippe, A., Guérin, G. & Kreutzer, S. BayLum - An R package for Bayesian analysis of OSL ages: An introduction. Quaternary Geochronology 49, 16–24 (2019).

How to cite: Sellwood, E., Malservet, H., and Guérin, G.: Investigating the cyclicity of Neanderthal occupations at Chez-Pinaud, SW France, using high-resolution OSL dating and Bayesian analysis., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12656, https://doi.org/10.5194/egusphere-egu25-12656, 2025.

Continental sedimentary deposits are essential geological records for understanding landscape evolution over time. In this context, the “modern analog” approach is employed in the Andes-Amazon system to deepen the understanding of past changes and the factors influencing them. This methodology involves studying contemporary fluvial deposits using advanced techniques and methods to identify how natural processes shape the current landscape. The main objective of this study is to determine the spatial variability and environmental controls of the sediment provenance and the erosion rates in modern deposits of the Ucayali, Maranõn, Napo, Madre de Dios, Huallaga, and Solimões rivers in the Andes-Amazon fluvial system. This approach will involve luminescence sensitivity signatures of quartz and feldspar grains, which can indicate grain source and transport process; the latitudinal gradient of erosion rates using in situ cosmogenic nuclides; the relationship between sedimentary variability and tectonic, topographic, lithologic, and climatic controls using Geographic Information Systems (GIS). The new cosmogenic nuclide and luminescence data will be used together to evaluate the compatibility of these methods in analyzing sediment provenance and erosion rates. This comparison will assess whether these methods and approaches can be consistently integrated, contributing to a more comprehensive understanding of sedimentary and erosive processes in the Andes-Amazon fluvial system. (FAPESP #2023/16318-1)

How to cite: Brandino de Campos, G., Barbosa Leite Cruz, C., Emerich Souza, P., Luísa Souza Simões, A., Breda, C., Cassimiro Brito, R., Bookhagen, B., Oliveira Sawakuchi, A., and Nascimento Pupim, F.: Sediment provenance and erosion rates in the Andes-Amazon fluvial system: a study using luminescence and cosmogenic nuclides technics, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12755, https://doi.org/10.5194/egusphere-egu25-12755, 2025.

Since the 19^th century, various authors have assigned the glacial landforms in the lower valleys of northern Italy to different ice ages (Penck and Brückner 1909). This study was part of a project that involved a broad geomorphological analysis and the first-time absolute in-situ exposure dating of erratic boulders using ¹⁰Be and ³⁶Cl (Braakhekke et al. 2020). In addition to the cosmogenic analysis, seven radiocarbon samples were taken from a fluvial terrace outcropping 6 meters high along the Ticino River. Where possible, the samples were sieved to separate a bulk fraction (<125 μm) from the undefined organic fragments. Some samples were partly dissolved during the subsequent ABA preparation of all fractions. This way, we obtained up to four ages per initial sample: one each for the insoluble bulk fraction, the humic acid of the bulk, the organic fragments, and the humic acid of the organic fragments. The obtained radiocarbon ages vary significantly, with the extreme being thousands of ¹⁴C years between the insoluble bulk fraction and the organic fragments for the same sample. For all samples, radiocarbon analysis of the bulk fractions gave much younger ages than the hand-selected macro remains. Here, we discuss the age differences and possible sources of old and young carbon found in samples. The ages of the organic fragments showed the most consistency over the whole profile, and these fragments are least likely contaminated by younger material. Based on our results obtained on macro remains, this deposit is dated to MIS3 age. About 3 meters of fine-grained sediment were deposited here during ca. 8 ky. This could tell us more about the sediment budgets during some of the (Greenland) stadial-interstadial oscillations at the outlet of a major lake (e.g., Lake Maggiore) and the erosive power of glaciers during a phase preceding the global Last Glacial Maximum.

References

Braakhekke J, Ivy‐Ochs S, Monegato G, Gianotti F, Martin S, Casale S, and Christl M. 2020. Timing and flow pattern of the Orta glacier (European Alps) during the last glacial maximum. Boreas 49: 315-332.

Penck A, and Brückner E. 1909. "Die alpen im Eiszeitalter." Tauchnitz.

How to cite: Hajdas, I., Braakhekke, J., Monegato, G., Gianotti, F., Christl, M., and Ivy Ochs, S.: Different 14C ages for various fractions of peat, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12806, https://doi.org/10.5194/egusphere-egu25-12806, 2025.

Anthropogenic carbonates such as lime mortars and plasters have been receiving growing attention as they are an invaluable source of information for archaeologists, conservators, and restorers of cultural heritage. Taking into account the production process, the age of mortars reflects the age of the building. Two physical dating methods currently enable us to date mortars: radiocarbon (¹⁴C) dating and optically stimulated luminescence (OSL). Fast development in ¹⁴C and OSL mortar dating naturally widens the scope of performed analysis, and promotes the search for different methods which may be applied to these materials. In this study we present the analysis of historical lime mortars in order to assess the possibility of future dating by Electron Spin Resonance (ESR) spectroscopy. ESR dating has been applied to various geological and archaeological materials, but there are virtually no examples of dating carbonates younger than 10 000 years. Since carbonate crystals are formed during the mortar production, this moment can be regarded as the zero point for the accumulation of trapped charges, and their concentration in a measured sample should reflect the age of the mortar.

Our previous works on samples from Sveta Petka church in Budinjak, Croatia, and an ancient settlement Hippos, Israel, show the growth of signals related to the paramagnetic centres with the dose of laboratory radiation. However, in order to obtain the age of the samples the natural material should exhibit measurable ESR signals of the centres suitable for dating. In the relatively young (as far as ESR dating is concerned) materials the signals are very weak, however detailed analyses showed presence of such signals in several investigated mortar samples. In this work we investigate ESR signals in natural and laboratory-irradiated carbonate lime binders from several different archaeological sites, with ages ranging from about 2000 to 500 years old. The samples have been previously dated by ¹⁴C method, which means they had undergone extensive characterisation and preparation, ensuring the selection of binder, which reflects the true age of the mortar. We analyse the spectra with the aid of ESR simulations in order to identify the paramagnetic centres present in the samples, and compare them to the centres commonly found in carbonates and used for ESR dating. The goal of this work is a qualitative analysis of the natural signals found in a variety of mortars, assessing their potential suitability for ESR dating. This study is a first part of the ongoing project focused on establishing ESR as a method of dating anthropogenic carbonates in a form of lime mortars, and comprises the preliminary analysis of the subject, which will be followed by future in-depth studies.

How to cite: Kabacińska, Z. and Michalska, D.: Towards Electron Spin Resonance dating of anthropogenic carbonates: ESR signals of 14C-dated historical lime mortars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13244, https://doi.org/10.5194/egusphere-egu25-13244, 2025.

We have studied the loess-palaeosol sequences of the Khovaling Loess Plateau in Tajikistan, which form the most complete record of subaerial sedimentation in Central Asia. Studied sections contain several layers with Early and Middle Palaeolithic tools, and therefore record some of the earliest events of hominin dispersal into Central Asia.

As part of a major NordForsk funded project ‘Timing and Ecology of the Human Occupation in Central Asia’ (THOCA; www.thoca.org), we applied high-resolution luminescence dating to the upper parts of three sections of Khovaling loess plateau (Khonako-II, Kuldara, and Obi-Mazar) in order to: (1) provide an independent timescale for palaeoclimatic studies; (2) assess the completeness of the sedimentary record; and (3) investigate the main stages of dust accumulation over this interval.

The luminescence chronology extends back to ~250 ka and reveals distinct erosional hiatuses ranging in duration from ~7 ka to a full glacial-interglacial cycle (~100 ka). Some of these breaks were not identifiable in the field. These discontinuities had not been previously recognized, potentially leading to significant errors in palaeosol identification and, consequently, in the presumed chronology. Now, we have a better understanding of the aeolian sedimentation in the region and the stages of loess/palaeosol formation. The new chronology provides a reliable correlation of regional features with global events and relates them to climate change, soil cover development, and the evolution of Early and Middle Paleolithic.

How to cite: Taratunina, N., Buylaert, J.-P., Challier, A., Murray, A., Sosin, P., and Kurbanov, R.: High resolution luminescence dating of the Khovaling Loess Plateau sites (Tajikistan), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13277, https://doi.org/10.5194/egusphere-egu25-13277, 2025.

Surface and buried paleosols are a significant archive of information about environmental change and are widely used in paleogeographic reconstructions. Soil features and their profiles change over time as a result of environmental change. The soil memory is the palimpsest-like, as opposed to the book-like, sedimentary record (Targulian and Goryachkin, 2004). The palimpsest-like memory of the soil requires informed and well-adapted strategies for deciphering and interpreting the information it contains. The question of soil age and its synchronization with reconstructed events remains one of the most controversial issues in paleosol interpretations. The complexity of the interpretation of obtained radiocarbon dates is related to the heterogeneous and heterochronous of soil organic matter (SOM). At present, there are many approaches to dating SOM, but for the paleosol for paleogeographic reconstructions, ¹⁴C dating is most often performed on total organic carbon (bulk carbon). This choice of dating fraction is usually related to the poor preservation of SOM and its low carbon concentration in paleosols. Dates obtained for SOM in buried soils are based on the assumption that SOM was formed "in situ". However, due to various natural processes, paleosols can contain carbon from a number of potential sources.
For buried soils formed in periglacial landscapes, a significant source of carbon is the supraglacial material: cryoconites and other organo-mineral formations that form on the surface and in the body of the glacier and enter the landscape during glacial melting. Our studies on glaciers and in periglacial landscapes of different natural zones (Svalbard, Franz Josef Land Archipelago, Polar Urals, Altai, Kamchatka) have shown that supraglacial material can have a radiocarbon age ranging from modern to very ancient (several thousand, sometimes tens of thousands of years). The largest dataset we have obtained for supraglacial objects is represented by carbon pools aged 1000 to 10,000 radiocarbon years, BP and >10,000 radiocarbon years, BP. The pool with an age of >10,000 radiocarbon years is associated with the presence of a "dead carbon" source near the studied glacier. Dates in the range of 10,000-20,000 radiocarbon years may also reflect the age of soils and sediments formed during the last deglaciation and buried within the body of the glacier as it advanced. Soils formed in the periglacial zone inherit the isotopic composition of SOM from supraglacial material and become carriers of "apparent" / inherited ¹⁴C age. The presence of cryoconite material in buried paleosols can be diagnosed by studying their micromorphology and identifying morphological structures characteristic of cryoconites. We have shown this for soils formed on cryoconite material in Svalbard and for lenses of buried fine-grained material in marginal glacial formations (Keiva) on the Koly Peninsula.  When ¹⁴C dating paleosol series (traditional paleoarchives are studied in foothills and mountainous areas), it is necessary to consider the ice-carbon contribution to SOM in order to make correct paleo-reconstruction.

How to cite: Zazovskaya, E., Mergelov, N., Dolgikh, A., Turchinskaia, S., Dobryanskiy, A., and Bronnikova, M.: “Ice carbon” as a possible source of apparent age in paleosol dating, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14514, https://doi.org/10.5194/egusphere-egu25-14514, 2025.

Abstract: The SAR-SGC method, integrating single aliquot regenerative (SAR) and standardised growth curve (SGC) protocols with advantages of saving machine measurement time. It has gained widespread application in recent years over diverse sediment types, including glacial, aeolian, fluvial, lacustrine, deltaic, and marine sediments. The method constructs inter-aliquot SGCs using conventional SAR measurements and determines SGC D_es by inserting the L_N/T_N values of additional aliquots into the SGC. The final SAR-SGC De is obtained by calculating the arithmetic mean of the SAR D_es and SGC D_es. However, the optimal number of SAR and SGC aliquots for reducing machine time while retaining precision, is still ambiguous. To address this issue, we systematically investigated how varying the number of SAR aliquots and additional L_N/T_N​ measurements influences the stability and consistency of equivalent dose derived from SAR-SGC method with SAR protocol. We examined the minimal SAR-SGC combinations for three samples (JNZK01-G09, MW10-G16 and XBG06-G07, with an equivalent dose of ~44 Gy (with largest scatter in inter-aliquot SAR growth curves), ~46Gy and ~55Gy (with marginal scatter in inter-aliquot SAR growth curves) in the lower Yellow River plain, utilizing a Risø TL/OSL-DA-20 reader with a 90Sr/90Y beta source. Through extensive statistical evaluations, SAR-SGC estimation of the equivalent dose obtained with differing aliquot combinations shows that equivalent dose could be accurately estimated within acceptable uncertainty (<10%) using 6–15 SAR aliquots and additional 12–30 L_N/T_N aliquots. For samples with dispersed growth curves, we recommend a minimum of 6 SAR and 12 L_N/T_N aliquots for reliable age determination. And samples with concentrated growth curves may suffice with 4 SAR and 10 L_N/T_N aliquots. This study demonstrates that the combined SAR-SGC method significantly reduces machine time (at least 70%) compared to the SAR protocol alone while maintaining acceptable precision. These findings provide valuable guidance for luminescence dating laboratories and researchers in optimizing instrument usage under time constraints.

Key words: SAR-SGC method; Standardized growth curve; Single aliquot regenerative protocol; Equivalent dose; Luminescence dating; Statistical analysis; Machine time optimization

How to cite: Zhou, X., Liu, Y., Feng, X., and Lai, Z.: Performance of SAR-SGC method for equivalent dose determination of quartz OSL, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15342, https://doi.org/10.5194/egusphere-egu25-15342, 2025.

Stone fish traps and weirs are the most common archaeological remains in fluvial and coastal environments. In Brittany, almost 800 of them were identified by Daire and Langouët (2014). Usually, these are made of numerous erected stones, that more or less precisely outline an alignment. Dating these remains represents a real archaeological issue, since stone fish traps have been raised for millennia, presumably from the early Neolithic to the Middle Ages. However, it is also a challenge as there is no organic matter preserved in the core of these structures.

In this presentation, we assess the age of fish weirs found in Brittany by comparing their altitude with the sea-level rise estimation curve since the last glaciation 20 000 years ago. A software named CHRONOE was developed in R in order to improve the reliability of the data, among which tidal curves (García-Artola et al. 2018). Statistical analysis – using the R package ArchaeoPhases (Philippe and Vibet 2020) – of the ages determined by CHRONOE for a corpus of    diverse stone fishing weirs, identifies periods of intensification and rarefaction of fishing using such structures. Thus, it is possible to discuss the evolution of fishing practices in human societies along the coasts of Brittany.

This work is the first step of a PhD Thesis; it will be followed by direct dating of stone fish traps. Indeed, rock surface luminescence dating \autocite{soh12} has been shown to reliably estimate the last time a rock surface was exposed to light (Sohbati et al. 2012) has been shown to reliably estimate the last time a rock surface was exposed to light (Freiesleben et al. 2015). Therefore, it will be applied to a few of these structures, after careful selection based on their presumed age. The bottom surface of sampled rocks from fish weirs will be sampled for OSL intensity profiling and burial dating. The numerical absolute ages given by obtained with OSL will then be compared to those assessed with CHRONOE, to discuss the reliability of the underlying assumptions and refine the model. Eventually, CHRONOE may hold the potential to date any submerged object whose utility (or existence) is linked with the intertidal zone.

Keywords : geochronology, OSL, archaeology, fish weirs.

References

Daire, M.-Y., & Langouët, L. (2014). Se nourrir le long des côtes bretonnes : Réflexions à partir d'une analyse diachronique des barrages de pêcheries. Actes des congrès nationaux des sociétés historiques et scientifiques, 138 (2), 105133.

Freiesleben, T., et al. (2015). Mathematical model quantifies multiple daylight exposure and burial events for rock surfaces using luminescence dating. Radiation Measurements, 81, 1622.

García-Artola, A., et al. (2018). Holocene sea-level database from the atlantic coast of europe. Quaternary Science Reviews, 196, 177192.

Philippe, A., & Vibet, M.-A. (2020). Analysis of archaeological phases using the R package ArchaeoPhases. Journal of Statistical Software, 93, 125.

Sohbati, R., et al. (2012). Optically stimulated luminescence (OSL) as a chronometer for surface exposure dating. Journal of Geophysical Research: Solid Earth, 117, 2012JB009383.

How to cite: Jumaucourt, A., Guérin, G., Le Bris, D., Stephan, P., Bernier, I., and Pailler, Y.: A way to date stone fish weirs ? Some perspectives., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19154, https://doi.org/10.5194/egusphere-egu25-19154, 2025.

Holocene sedimentary sequences lacking organic remnants or containing redeposited organic material pose a challenge for detailed chronological investigations, as radiocarbon dating is unsuitable. Optically stimulated luminescence (OSL) can be used instead, but high-resolution OSL is costly. A more cost-effective and efficient approach involves the combination of low-resolution OSL dating with portable OSL (pOSL) profiling in 5–10 cm increments (e.g. Sanderson and Murphy, 2010; Brill et al. 2016). This method has been employed in the analysis of cored lacustrine sedimentary sequences from the northern shore of Lake Schweriner See, Germany.

In well-bleached Holocene sediments, quartz equivalent doses and portable post-infrared blue-light stimulated luminescence signals (further pOSL) from the polymineral fraction are linearly correlated (e.g. Brill et al., 2016). We used the obtained linear functions to estimate equivalent doses (D_es) in quartz for each pOSL signal. The dose rates were then interpolated between full OSL samples, and the ages were calculated by dividing the D_es by the corresponding dose rates. Finally, both the quartz full OSL ages and the ages derived from the pOSL signals were incorporated into a Bayesian age-depth model to obtain a continuous chronology.

The pOSL-to-D_e ratio is also a useful tool in the identification of incompletely bleached samples. Poorly bleached sediments exhibit a higher pOSL-to-D_e ratio in comparison to well bleached sediments because pOSL is a composite of signals from quartz and feldspars, which require a greater exposure time for complete bleaching than OSL from pure quartz (e.g. Murray et al., 2012). In the littoral sequences studied, elevated pOSL-to-D_e ratios were found to correspond with high quartz D_eoverdispersion (OD), which is another indicator of poor bleaching. One particular sample was observed to exhibit a high pOSL-to-D_e ratio yet low OD (15%), which may be attributed to distinct OSL sensitivity linked to a specific sediment source.

Our results demonstrate that the proposed approach suits littoral sediments and improves chronological frameworks for lacustrine sequences. A potential avenue for further refinement of age-depth models lies in the measurement of dose rates for all pOSL samples, as opposed to their estimation through interpolation.

References

Brill, D., Jankaew, K., & Brückner, H. (2016). Towards increasing the spatial resolution of luminescence chronologies – Portable luminescence reader measurements and standardized growth curves applied to a beach-ridge plain (Phra Thong, Thailand). Quaternary Geochronology, 36, 134–147.

Murray, A. S., Thomsen, K. J., Masuda, N., Buylaert, J.-P., & Jain, M. (2012). Identifying well-bleached quartz using the different bleaching rates of quartz and feldspar luminescence signals. Radiation Measurements, 47(9), 688–695.

Sanderson, D. C. W., & Murphy, S. (2010). Using simple portable OSL measurements and laboratory characterisation to help understand complex and heterogeneous sediment sequences for luminescence dating. Quaternary Geochronology, 5(2–3), 299–305.

How to cite: Ruchkin, M., Lorenz, S., Adolph, M.-L., and Haberzettl, T.: Applying portable OSL to obtain a detailed chronology of littoral sedimentary sequences from the northern shore of Lake Schweriner See, Germany, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21256, https://doi.org/10.5194/egusphere-egu25-21256, 2025.

The thermo-tectonic history of an orogenic belt can be investigated using data on metamorphic grade, thermochronology, and structural geology. However, in the strongly deformed and poorly exposed terrains, field observation and structural correlation present challenges that hinder the construction of large-scale structural frameworks. Previous studies demonstrate that LiDAR-based digital elevation model (LiDAR DEM) reveals geomorphic lineaments caused by interactions between planar geological structures and surface processes. The delineation of these lineaments offers a systematic and comprehensive perspective on regional structures, helping to overcome limitations posed by poor exposure.

In this study, we use 3D mapping of LiDAR DEM and relevant datasets, along with field mapping, to investigate the structural architecture of the strongly deformed and metamorphosed south-central Cenozoic Western Slate Belt in the Central Range of Taiwan. Although the metamorphic grade and low-temperature thermochronologic data are well-established in this region, the structural framework remains unclear, and the relationship between metamorphism and tectonic events is still controversial. Our 3D LiDAR mapping reveals two suites of structural lineaments of interest: bedding (S_b) and metamorphic foliation (S_f). Based on their morphology and field validation, S_b is associated with thick-layered metasandstone and metavolcanic layers, while S_f results from fracturing along an east-dipping, pervasive, and penetrative slaty cleavage. The regional pattern of S_b reveals a previously unmapped, approximately 10 km wavelength, west-facing, tightly folded overturned synform, referred to as the 'Siangyang Synform.' The S_f is axial planar to the Siangyang Synform, suggesting that the cleavage and regional-scale fold developed simultaneously, which is supported by field observations.

This study demonstrates the value of integrating 3D LiDAR mapping and field surveys in strongly deformed metamorphosed terrains. While the orientation and regional patterns of thick-layered, competent rocks are difficult to determine through field surveys alone, they are discernible using the stereo view of LiDAR DEM, revealing macroscopic structural features. By integrating the new structural architecture with published RSCM temperature and geochronologic data, the regional geologic framework shows the peak thermal event postdates or synchronize with the syn-orogenic ductile deformation, highlighting the significance of syn-orogenic undethrusting and metamorphism of the Western Slate Belt during the late-Cenozoic arc-continent collision in Taiwan.

How to cite: Chen, Y.-P., Chan, Y.-C., Wang, Y., and Wei, W.-T.: High-resolution 3D LiDAR mapping of geologic structures: Implications for thermo-tectonic history in the Taiwan Slate Belt, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-126, https://doi.org/10.5194/egusphere-egu25-126, 2025.

Over geological time scales, tectonics and climate exert a first-order control on erosion distribution and efficiency, thereby influencing the evolution of fluvio-glacial mountainous landscapes. This is particularly the case in the Patagonian Andes, a tectonically active region spanning more than 1500 km from North to South. The present landscape has been significantly impacted by the action of erosion and tectonics over different glacial/interglacial cycles during the last 5-6 Ma. Rock cooling history for the region has been previously inferred from bedrock low-temperature thermochronology, whose representativeness may be questioned, as large areas are currently inaccessible, notably due to the presence of ice. Here, we make use of glacial deposits (terminal moraines) that are well preserved in the present landscape, to retrieve information on the erosion history of the region assuming that these deposits are representative of the entire glacial catchment. We present the first results of a multi-method approach applied to the General Carrera-Buenos Aires Lake (GCBA) area, including: (1) apatite fission track (AFT) and U-Pb double dating of samples collected within different moraine complexes east of the GCBA lake, and (2) inverse thermal history modeling using our new detrital data and available in-situ low-temperature thermochronological data. The inference of the thermal histories involves the prediction of elevation profiles, the estimation of detrital age distributions, and the inference of a topographic sampling function (TSF) for each detrital sample. Dating of detrital apatites reveal numerous AFT ages that are older than those observed in in situ/bedrock data from the same glacial catchment. Inverse modelling suggests that these older AFT ages are likely to have sourced from areas at high elevation. We further explore the potential causes for the observed differences in age distributions, which may include: (a) potential biases in the separation process, (b) differences in erosion processes through the catchment, (c) differences in sediment transport and storage processes.

How to cite: Gómez, R., Guillaume, B., Gallagher, K., Cogne, N., Nativ, R., and Barrionuevo, M.: Detrital low thermochronology applied to moraine deposits in the central Patagonian Andes , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1728, https://doi.org/10.5194/egusphere-egu25-1728, 2025.

The tectonic history of Central Europe, located within the interior of the Eurasian plate, is characterised by episodic fault reactivations extending into the Cenozoic. Determining the exact timing of repeated activity along continental intraplate faults is key to understanding the underlying forces driving lithospheric deformation, mantle convection, and geodynamic processes. In particular, lithospheric flow has been proposed as a mechanism capable of reactivating pre-existing fault zones, but its contribution to deformation in Central Europe is not yet well-constrained.

The Variscan Bohemian Massif provides a key setting for this study, with granitic plutons featuring a complex structural and lithological architecture that reflects a prolonged history of deformation. The area is predominantly composed of 312–325-Ma-old granitic rocks intruded into the metamorphic basement during the Variscan orogeny. These rocks are crosscut by numerous fault zones, including the prominent NW–SE-striking Danube fault zone, which has been periodically reactivated under varying stress regimes. Despite its young morphology, the post-Variscan deformation history of the Danube fault zone remains poorly constrained.

By integrating ⁴⁰Ar/³⁹Ar thermochronology with U-Pb dating of calcite slickenfibres and K-Ar dating of illite from fault gouges in nine different quarries in bedrock northeast of the Danube fault, we reconstruct the temporal and kinematic evolution of these faults. Our results reveal a multi-phase reactivation history, with significant tectonic activity persisting into the Cenozoic. ⁴⁰Ar/³⁹Ar analysis of K-bearing minerals from deformed host rock yielded the oldest dates, ranging from 232 to 331 Ma, with K-feldspars showing the largest intra-outcrop variations of up to 10 Myr, likely indicating localised resetting of the ⁴⁰Ar/³⁹Ar clock. K-Ar dates of illite, spanning from 173.2 ± 4.0 Ma to 204 ± 5.3 Ma, reveal evidence of brittle deformation resulting in clay gouge formation. Complementary U-Pb dating of synkinematic calcite slickenfibres on subsidiary fault planes up to 10 km from the main fault, with ages ranging from 45.7 Ma to 0.82 Ma, provides precise temporal constraints and preliminary insights into the timing of deformation. The complementary analysis of mineral parageneses within the dated faults reveals multiple phases of mineral formation and distinct fluid compositions, indicating varying low temperature and pressure conditions (50 – 200 °C; <1.2 GPa). We observed a transition of the Danube Fault from higher-temperature deformation (200–300°C) in the Triassic to near-surface faulting and fluid activity (<150°C) during the Cenozoic. The thermal evolution inferred from our detected mineral assemblages aligns with previously obtained Apatite Fission Track (AFT) ages, indicating low-temperature thermal events (<120°C) related to near-surface exhumation processes.

Our results underscore the importance of detailed analysis of deformation inventory in intraplate setting over geological timescales. The temporal and kinematic data from this study provide a critical contribution to refining the timing and constraining the duration over which currently available stress field models are applicable. Additionally, these data offer a framework for understanding the evolution of intraplate fault systems through integrated radiometric, petrological, and geochemical analyses.

How to cite: Ludat, A. L., Aßbichler, D., Friedrich, A. M., Hofmann, F., Bolhar, R., Hahn, T., and Zwingmann, H.: Unravelling Fault Reactivation History: Geochronological Insights from a Major Intraplate Fault in the Bavarian Forest, Germany, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1928, https://doi.org/10.5194/egusphere-egu25-1928, 2025.

Due to the complex evolutionary history and the limited understanding of the western Junggar region, studies on the genesis and formation environment of volcanic rocks in the Kebai fault zone remain insufficient. This study employs SHRIMP zircon U-Pb dating, as well as geochemical analyses of elements and isotopes, to investigate the eruption age, petrogenesis, and tectonic setting of Carboniferous volcanic rocks in the Kebai fault zone. The U-Pb age of SHRIMP zircon from tuff samples is 316.8±1.7 Ma, while the U-Pb age of basalt LA-ICP-MS zircon is 321.7±1.8 Ma, both of which correspond to the early Late Carboniferous volcanic eruption. Stratigraphically, these volcanic rocks correlate with the Genghis Khan Formation in the region. The volcanic rocks are classified as calc-alkaline, with SiO2 content ranging from 53.46 wt% to 61.57 wt%, TiO2 content from 0.75 wt% to 1.20 wt%, and a K2O/Na2O ratio between 0.10 and 0.66, exhibiting a sodium-rich and potassium-poor signature. Light rare earth elements (LREE) are relatively enriched, while heavy rare earth elements (HREE) are relatively depleted, as evidenced by (La/Yb)N ratios ranging from 2.72 to 7.89. Large ion lithophile elements (LILEs) such as Ba, Th, U, and Sr are enriched, while high field strength elements (HFSEs) such as Nb, Ta, Zr, and Hf are depleted. The δEu values range from 0.17 to 0.35, displaying a weak negative Eu anomaly. The Zr/Nb (29.36–65.60) and Hf/Ta (12.82–30.16) ratios are significantly higher than those of ocean island basalts (Zr/Nb = 3.0–6.0, Hf/Ta = 10–20) and mid-ocean ridge basalts (Zr/Nb = 10–30, Hf/Ta = 8–15). The volcanic rocks exhibit low (87Sr/86Sr)i values (0.703941–0.705675) and positive εNd(t) values (7.5–8.0), indicating a mantle-like isotopic signature. The Zr-Nb, Th/Zr-U/Th, and Ce/Pb diagrams (values ranging from 2.52 to 13.38, mean 4.61) suggest the involvement of subduction-zone fluids during the volcanic formation process. Furthermore, the Hf/3-Th-Ta, Nb×2-Zr/4-Y, V-Ti/1000, and La/10-Y/15-Nb/8 identification diagrams support the conclusion that the volcanic rocks in the Kebai fault zone were primarily influenced by ridge extension and subduction processes, consistent with a backarc basin extensional tectonic environment.

How to cite: Zongquan, Y., Wei, W., Yan, G., and Zongrui, X.: Genesis of Late Carboniferous volcanic rocks in Kebai Fault zone, Western Junggar, Xinjiang: constraints from SHRIMP zircon U-Pb age, whole rock geochemistry and Sr-Nd-Pb isotopes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2111, https://doi.org/10.5194/egusphere-egu25-2111, 2025.

The Tibetan Plateau is currently the widest and highest elevation orogenic plateau on Earth. It formed as a response to the Cenozoic and still ongoing collision between the Indian and Eurasian plates. The Xigaze fore-arc basin is located along the suture zone of both plates, i.e. the Indus Yarlung suture zone in southern Tibet. This area preserves important information related to the late Cenozoic tectonic and topographic evolution of the Tibetan plateau. In this study, apatite fission track (AFT) thermochronology was carried out on twelve sandstone samples from the middle segment of the Xigaze basin and additionally on four sedimentary rocks from the neighboring Dazhuka (Kailas) and Liuqu Formations. Inverse thermal history modeling results reveal that the fore-arc basin rocks experienced episodic late Oligocene to Miocene rapid cooling, which we interpret as the exhumation of these rocks. Taking into account regional geological data, it is suggested that the late Oligocene-early Miocene (~27-18 Ma) cooling recognized in the northern part of the basin was related to fault activity along the Great Counter thrust, while mid-to-late Miocene-accelerated exhumation was facilitated by strong incision of the Yarlung and Buqu rivers, which probably resulted from enhanced East Asian summer monsoon precipitation. Sandstone and conglomerate samples from the Dazhuka and Liuqu Formations yielded comparable Miocene AFT apparent ages to those of the Xigaze basin sediments, indicative of (mid-to-late Miocene) exhumation soon after their deep, early Miocene burial (> ~3-4 km). Additionally, our new and published low-temperature thermochronological data indicate that enhanced basement cooling during the Miocene prevailed in vast areas of central southern Tibet when regional exhumation was triggered by both tectonic and climatic contributing factors. These events ultimately led to the formation of the high-relief topography of the external drainage area in southern Tibet, including the Xigaze fore arc basin.

How to cite: Song, S., He, Z., Su, W., Zhong, L., Zhong, K., Glorie, S., Song, Y., and De Grave, J.: Late Cenozoic cooling history of the Xigaze fore-arc basin along the Yarlung-Zangpo suture zone (southern Tibet): New insights from low-temperature thermochronology , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4183, https://doi.org/10.5194/egusphere-egu25-4183, 2025.

We present a new application of a verified method for determining the relative significance of numerical simulation input parameters. The Taguchi method is commonly used in process engineering to reduce the number of experiments necessary to determine the sensitivity of systems to independent variables. We apply this method to thermal-kinetic and thermal-kinematic modeling as a means to efficiently determine the impact of uncertainties associated with primary assumptions for simulation input parameters on model-derived exhumation histories. The rate of rock uplift is important for determining the nature of the evolution of mountain belts, as well as the relative influence of tectonic and surface processes. Interpretation of thermochronometric datasets is already known to depend on a large and variable number of parameters - such as surface topography, geothermal gradient, exhumation rate, erosion, faulting, and rock properties - yet the impact of primary assumptions associated with these parameters is still uncertain. We are specifically interested in which assumptions impact geological interpretations most. Our novel application of the Taguchi method to thermal-kinematic modeling is compared with a full sensitivity analysis for increasingly complex numerical systems, and we find that the method is both as robust as the exhaustive approach and holds the potential for efficiently analyzing the relative influence of a large number of input parameters in complex simulations.

How to cite: Sparks, S. and Hodges, K.: Thermochronometric design of experiments - applications of the Taguchi method and implications for thermal-kinematic model parameter sensitivity analysis, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7535, https://doi.org/10.5194/egusphere-egu25-7535, 2025.

Understanding the thermal evolution of sedimentary basins is critical to hydrocarbon accumulation, as it influences basin development, hydrocarbon generation, migration, and the formation of source rocks and reservoirs. While paleothermometry, primarily applied to organic matter and heavy minerals, has traditionally been the standard method for reconstructing basin-scale thermal histories, marine carbonate strata lack conventional paleothermometers, posing a significant challenge. Clumped isotope analysis, however, offers a promising alternative, leveraging temperature-dependent ¹³C-¹⁸O bond reordering influenced by lattice defects. Recent advancements in modeling approaches—such as first-order approximation (Passey et al., 2012), transient defect models (Henkes et al., 2014), paired reordering/diffusion models (Stolper et al., 2015), and continuous first-order reaction models (Hemingway et al., 2021)—have broadened the applicability of clumped isotopes across diverse geological contexts. However, applying clumped isotope solid-state reordering models without constrained thermal history paths may lead to significant discrepancies in simulation outcomes. To improve accuracy and reduce uncertainty, this study integrates fluid inclusion microthermometry, U-Pb dating, and vitrinite reflectance (R_o) to jointly constrain thermal history paths.

The Ordos Basin, a major hydrocarbon-bearing region in northwestern China, has undergone complex tectonic and depositional transformations, particularly during the Caledonian Orogeny, which obliterated sedimentary records from the Late Ordovician to Early Carboniferous periods. To address the challenges of reconstructing its thermal history, this study combines clumped isotope thermometry, U-Pb dating, fluid inclusion analysis, petrography, X-ray diffraction, and carbon-oxygen isotope analysis. Clumped isotope reordering simulations in calcite cements, constrained by in situ U-Pb dating and fluid inclusion microthermometry, reveal Ordovician paleotemperatures of 180–190°C during the Cretaceous. Similarly, reordering simulations in micritic matrices, supported by R_o and fluid inclusion microthermometry, indicate paleotemperatures of 170–200°C during the Caledonian, a period characterized by deep burial and accelerated source rock maturation. These findings provide critical insights into the thermal history of Ordovician strata in the Ordos Basin, offering valuable guidance for hydrocarbon exploration and advancing our understanding of early hydrocarbon generation processes.

Additionally, this study examines core samples from different depositional environments within a single well, utilizing petrography, Sr isotope, and trace element analyses. Variations in Δ47 clumped isotope values among dolomites from distinct depositional settings suggest that factors such as paleo-salinity and microbial sulfate reduction (MSR) significantly influence Δ47 values. By incorporating clumped isotope kinetic models, this study also investigates the impact of microbial activity, pH, and temperature on ancient dolomite formation. These findings provide a theoretical framework for further research into the formation mechanisms of ancient dolomites in sedimentary strata.

How to cite: Du, H., Liu, Y., and Zeng, S.: Application of clumped isotope solid-state reordering to thermal evolution: A case study of Ordovician strata in Ordos Basin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8103, https://doi.org/10.5194/egusphere-egu25-8103, 2025.

Low-temperature thermochronology dates mineral cooling through the upper crust, enabling us to constrain the rate and timing of landscape evolution over a range of spatial-temporal scales (Reiners et al. 2005). However, constraining recent thermal histories over timescales of 10⁵−10⁶ years at temperature ranges between 25 and 75 ^oC remains a challenge owing to a lack of temporal resolution from existing thermochronometers. Deciphering recent time-temperature histories (<100 ^oC, typically encompassing the upper <3 km of the Earth’s crust) is crucial for understanding the interactions between tectonics, erosion and climate over Quaternary timescales. To this end, trapped charge techniques like quartz Electron Spin Resonance (ESR) dating can exploit the low temperature sensitivity (<100 ^oC) of various paramagnetic defect centres (such as the Al and Ti centres) to determine thermal history over the Quaternary period. Thus, offering the potential to fill this temporal gap that otherwise remains elusive to classical thermochronology.  

The potential of quartz ESR thermochronometry has been previously investigated (Scherer et al. 1991; Grün et al. 1999; King et al. 2020 and references therein). However, this method is still in its developmental stages and lacks a robust validation study to calibrate its temperature sensitivity, and thereby the ability of quartz ESR centres to record thermal histories over Quaternary timescales. Towards this objective, we investigate quartz extracted from borehole sediments in the Anadarko Basin (Oklahoma, USA) with a known temperature history (varying vertically from ~30−80 °C; Carter et al., 1998) based on empirical calibration with a stable geothermal gradient. This study presents preliminary investigations on the kinetics of different ESR centres in the quartz samples and examines the challenges and potential of quartz ESR centres in reconstructing temperature histories in natural settings.

References:

Carter et al. 1998. Am Assoc of Petro Geo Bull 82: 291–316. https://pubs.usgs.gov/publication/70020705

Reiners et al. 2005. Rev in Min and Geochem 58 (1): 1–18. https://doi.org/10.2138/rmg.2005.58.1

Grün et al. 1999. J Geophys Res 104(B8): 17531–17549. 10.1029/1999JB900173

King et al. 2020. Geochron 2: 1–15. https://doi.org/10.5194/gchron-2-1-2020

Scherer, T. et al. 1994. KTB Rep. 94-2. B25, Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland, Niedersächs. Landesamt Bodenforsch.

How to cite: Dave, A. K., Kranz-Bartz, M., Jepson, G., Wen, X., Bernard, M., Schmidt, C., Margirier, A., and King, G. E.: Investigating temperature sensitivity of quartz Electron Spin Resonance (ESR) thermochronometry: Insights from the Anadarko Basin (Oklahoma, USA), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10864, https://doi.org/10.5194/egusphere-egu25-10864, 2025.

The interaction between surface processes, climate and tectonics determines the landscape in alpine regions, with lithology playing a key role. Carbonate rocks, which cover a significant portion of Earth’s terrestrial surface, are more sensitive to environmental changes such as dissolution by meteoric waters compared to siliciclastic or crystalline rocks. This distinct sensitivity makes carbonate rocks important in geomorphological studies, particularly regarding erosion rates. However, the factors influencing erosion rates in alpine carbonate areas remain poorly understood, especially over the (sub-)Quaternary period. Existing techniques are not well-suited to measure erosion rates in carbonate minerals over timescales of 10⁶ years due to limitations in sensitivity or applicability to carbonate rocks in alpine regions. This study explores the potential of electron spin resonance (ESR) signals in calcite as a novel thermochronometer to fill the spatial and temporal gap for constraining Quaternary rock cooling and exhumation rates in carbonate mountain landscapes.

An ideal setting for this investigation has been identified in the European Alps (Rhône Valley, Switzerland), where six samples were collected along vertical (~400-1100 m a.s.l., n=3) and horizontal (~400 m a.s.l., n=3) transects. Analysis of dose response and isothermal decay data from ESR signals demonstrates sufficient stability up to 10⁶ years, allowing us to invert low rock cooling rates (~10 °C/Myr). Our study highlights the potential of ESR thermochronometry of carbonate minerals, supported by several key findings: (i) multiple ESR signals with different thermal sensitivities can be measured in a single sample, (ii) high upper dating limits of 10⁶-10⁷ years, (iii) low closure temperatures (<80 °C), enabling the investigation of recent erosion processes, and (iv) the ability to constrain low exhumation rates of <1 mm/yr. By providing a reliable tool for constraining exhumation rates in carbonate mountain regions, ESR thermochronometry can significantly advance our understanding of the complex interactions between tectonics, climate, and surface processes over Quaternary timescales.

How to cite: Kranz-Bartz, M., Kabacińska, Z., Schmidt, C., Dave, A. K., Wen, X., and King, G. E.: Electron spin resonance (ESR) signals in calcite: a novel thermochronometer to constrain carbonate mountain erosion?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12480, https://doi.org/10.5194/egusphere-egu25-12480, 2025.

Convergent plate boundaries are among the most dynamic regions on Earth. These active margins, shaped by the interplay of tectonics, erosion, and climate, are characterised by the highest topography and extensive sediment transport across vast distances. In such complex systems, lithology plays a crucial role, not only influencing rock resistance to deformation, erosion, and weathering, but also posing challenges to the application of dating and rate-determination techniques that rely on specific target minerals. Carbonate landscapes, in particular, present additional difficulties in quantifying denudation and exhumation rates due to their unique chemical and physical properties. Additionally, mountain ranges are shaped by processes acting at different timescales, where a combination of techniques with different integration times is needed to define the temporal evolution of the system.

The application of Beryllium (¹⁰Be) cosmogenic nuclides for quantifying denudation and uplift rates can help to overcome such limitations. Firstly, the employment of meteoric ¹⁰Be in combination with in situ ¹⁰Be overcomes limitations posed by lithology (i.e., the dependence of in situ ¹⁰Be on quartz and feldspar), as meteoric ¹⁰Be does not depend on specific target minerals. Secondly, the integration time of this technique bridges the temporal gap between long-term geological processes revealed by thermochronology (10⁶ yr) and modern geodetic measurements (10¹ yr).

We tested this approach in the Albanides orogenic system, integrating it with geomorphic, topographic, and fluvial analyses to reconstruct the recent uplift and erosional evolution of this region, characterised by numerous lithologies and a complex tectonic history. Basin-wide denudation rates derived using both in situ and meteoric ¹⁰Be are used as proxies of regional uplift rates across the belt, bypassing lithological constraints. The results of these complementary analyses revealed a high degree of consistency, reinforcing the reliability of the methodology. Rates ranging up to 1.61 mm/yr indicate rapid erosion of the orogen, while their spatial distribution highlights strong correlations with active tectonic structures and evidence of river network reorganisation. Despite covering different timescales, our findings align with data from thermochronology, incision rates, and geodesy, suggesting that past processes continue to echo in the present landscape dynamics.

This study highlights the value of integrating geomorphological and cosmogenic nuclide data, particularly through the complementary use of in situ and meteoric Beryllium, to untangle the complex interactions between tectonics and surface processes in active orogenic belts characterised by carbonate lithologies.

How to cite: Bazzucchi, C., Crosetto, S., Ballato, P., Wittmann, H., Faccenna, C., Scherler, D., Rossetti, F., and Muceku, B.: Reconstructing uplift through denudation rates in carbonate systems: the Albanian orogen case study, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13241, https://doi.org/10.5194/egusphere-egu25-13241, 2025.

Late Mesozoic subduction and retreat of the Paleo-Pacific Plate constructed a vast back-arc region with numerous extensional basins and extensive magmatic activities that destroyed the east South China Craton.Widespread extensional structures are always controlled by detachment faults, which provide direct constraint ofthe precise tectonic process of craton destruction. At the westernmost end of this back-arc region, we identify a unique, two-detachment extensional system, the Yuechengling dome with the Ziyuan Detachment in the west and the Tianhu Fault at the middle. Low-temperature geochronology shows that during the extension at 100-85 Ma, the Ziyuan Detachmentevolved progressively with a north-to-south migration pattern. At the same time, the Tianhu Fault was also reactivated. Its northern segment experienced rapid cooling from 85-70 Ma, and the southern segment was in a rapid cooling stage from 70-45 Ma. This trend reflects heterogeneous evolution and exhumation related to the subduction retreat of the Paleo-Pacific. The uplift and denudation process from 10-0 Ma obtained from the thermal history inversion of the Tianhu Fault and the Ziyuan Detachment may be related to crustal thermal subsidence. According to the Airy - Heiskanen Model, combined with the regional low-temperature geochronology data, we calculated that the denudation thickness in the Yuechengling area reached approximately 2000 m. Combining with the current altitude, it is speculated that the altitude in the Yuechengling area reached approximately 2900 ± 300 m during the Late Mesozoic, and decreased after the thinning of the cratonic lithosphere of South China. Our results reveal a consistent structural and topographic change of regional extension and shed light in the coupling of deep and surface response to the cratonmodification and destruction.

How to cite: Liu, T., Chu, Y., Lin, W., Lei, Y., Guo, Y., and Guo, L.: Late Mesozoic extension and denudation of the South China Block: Insights from low-temperature geochronology into the differential evolution of detachment faults, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14334, https://doi.org/10.5194/egusphere-egu25-14334, 2025.

The influence of Quaternary climate (i.e., glacial-interglacial cycles) on mountain topography remains a topic of debate, largely due to the challenges associated with measuring surface processes over the recent geological past. A compelling location to investigate mountain erosion in response to Quaternary climate change is found in the Tateyama Mountains, part of the Hida mountain range in the northern Japanese Alps, due to its distinct geomorphological features. The Japanese Alps uplifted within the last 1–3 million years and have undergone multiple glaciations during the late Quaternary. In this study, we employ novel ultra-low temperature thermochronometers based on the luminescence and electron spin resonance (ESR) from feldspar and quartz minerals, respectively, in combination with numerical (inverse) modelling to derive rock cooling and exhumation rate histories on timescales of 10⁴–10⁶ years within the Tateyama region.

The different infra-red stimulated luminescence signals measured have already reached their upper dating limit, indicating maximum exhumation rates of approximately 1-1.5 mm/yr. In contrast, ESR signals from Al and Ti centres provided ESR ages ranging from ca. 0.3 to 1.1 million years, suggesting that surface processes were active during the Pleistocene. A negative age-elevation relationship reveals a reduction in local relief at the scale of the cirque basin over the past million years. However, a positive age-elevation trend observed in samples from near the mountain summit deviates from this pattern. Inverse modelling shows rock cooling rates ranging from 20 to 70 °C/Myr, with slightly faster cooling in cirque-floor samples. Both 1D and 3D thermal kinematic modelling reveal erosion rates of 0.5–1 mm/yr in the cirque basin, which are higher than those observed from periglacial and slope processes in the same area. Our data suggest that Quaternary climate change, coupled with distinct surface processes, has significantly altered the slopes of the Tateyama mountains, leading to a localized decrease in relief within individual cirque basins during the second half of the Quaternary (Bartz et al., 2024).

Bartz, M., King, G.E., Bernard, M., Herman, F., Wen, X., Sueoka, S., Tsukamoto, S., Braun, J., Tagami, T., 2024. The impact of climate on relief in the northern Japanese Alps within the past 1 Myr – The case of the Tateyama mountains. Earth and Planetary Science Letters 644, 118830.

How to cite: Kranz-Bartz, M., King, G. E., Bernard, M., Herman, F., Wen, X., Sueoka, S., Tsukamoto, S., Braun, J., and Tagami, T.: Unveiling the impact of Quaternary climate on mountain erosion: new insights from the Japanese Alps using novel trapped charge thermochronometry, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14764, https://doi.org/10.5194/egusphere-egu25-14764, 2025.

Exhumation plays a crucial role in shaping the evolution and distribution of resource systems in sedimentary basins, affecting mineral and energy resource exploration. Accurate exhumation estimates, derived primarily from empirical equations based on compaction and thermal datasets, are essential but are often compromised by data errors and unquantified uncertainties in model parameters. For instance, model parameters are usually assumed not to be affected by uncertainties despite varying within measurable ranges. Uncertainties from such variation can propagate and compromise the accuracy of exhumation estimates.

This study introduces a novel and refined approach to exhumation estimation using Markov Chain Monte Carlo (MCMC) methods to quantify and address uncertainties in data and model parameters. Using this approach, we developed a workflow for quantifying exhumation magnitudes and their associated uncertainties and applied it to sonic log datasets from the Canning and Bonaparte Basins. The impact of uncertainty propagation on exhumation results was assessed by examining four scenarios: assuming no uncertainty in the model or data, considering data noise without model uncertainty, considering model uncertainty without data noise, and considering model uncertainties and data noise together.

Our study yielded robust exhumation estimates in the Canning and Bonaparte Basins. Comparison with previous studies shows similarities and differences in exhumation estimates for multiple episodes, with discrepancies potentially arising from variations in exhumation models, data quality and coverage. Uncertainty propagation analysis reveals that considering data-related and model uncertainties together produces variable distributions of exhumation estimates with wider uncertainty ranges. Overall, data quality and coverage proved more critical for the accuracy and precision of exhumation estimates than model refinement. Our models can be integrated into basin evolution studies, help refine fluid migration models, and improve understanding of sedimentation and ore preservation to optimise resource exploration in sedimentary basins.

How to cite: Makuluni, P., Hauser, J., and Clark, S.: Assessment of Uncertainty Propagation within Compaction-Based Exhumation Studies Using Bayesian Inference, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15008, https://doi.org/10.5194/egusphere-egu25-15008, 2025.

Electron spin resonance (ESR) dating of quartz minerals offers a significant advantage over luminescence dating because of its later signal saturation. We seek to exploit this to develop a thermochronometry system capable of resolving rock cooling rates throughout the Quaternary. Whereas the luminescence thermochronometry system is limited to areas experiencing very rapid rock cooling (exhumation) of tens of mm/yr, recent studies have shown that ESR thermochronometry can resolve rates of <1 mm/yr over Quaternary timescales (e.g. Bartz et al., 2024). However, the method has not yet been validated against samples with known thermal histories. To this end, we have investigated six known-thermal history samples from the MIZ1 borehole, Tono, Japan. The low-relief Tono region, Japan, underwent Quaternary exhumation at rates of <1 mm/yrand previous luminescence thermochronometry (Ogata et al., 2022) on the same samples yielded saturated signals. Sample borehole temperatures range from 22.7 to 43.8 °C.

The natural trapped-charge concentration of the different samples was constrained using a single-aliquot regenerative dose measurement protocol. As the samples had similar properties, we constructed a standardised growth curve to alleviate measurement times. Signal saturation of the Al-centre occurred at ~60 kGy and at ~7 kGy for the Ti-centre. Whereas the Al-centre exhibited single-saturating exponential growth, the Ti-centre exhibited significant sub-linearity in the low dose region, within which the natural trapped-charge concentrations were interpolated.

The thermal stability of the different samples was measured using an isothermal holding experiment, whereby samples were dosed in the laboratory before being held at fixed temperatures (130 °C, 160 °C, 200 °C, 250 °C), for durations ranging from 4 min up to a cumulative duration of 10 h. As the thermal signal loss of the different samples was similar, we were able to fit all samples to derive a single set of thermal kinetic parameters.

Finally, the data were inverted for borehole temperature using a Monte-Carlo approach. Whereas the Al-centre of all samples recovered borehole temperature within 1s uncertainties, the Ti-centre data failed to recover temperature, yielding temperatures ~20-30 °C above borehole temperature. The cause for this is uncertain but is likely related to the observed sub-linearity of the dose response curves which may be indicative of sensitivity change throughout analysis.

Bartz, M., King, G.E., Bernard, M., Herman, F., Wen, X., Sueoka, S., Tsukamoto, S., Braun, J. and Tagami, T., 2024. The impact of climate on relief in the northern Japanese Alps within the past 1 Myr–The case of the Tateyama mountains. Earth and Planetary Science Letters, 644, p.118830.

Ogata, M., King, G.E., Herman, F. and Sueoka, S., 2022. Reconstructing the thermal structure of shallow crust in the Tono region using multi-OSL-thermometry of K-feldspar from deep borehole core. Earth and Planetary Science Letters, 591, p.117607.

How to cite: King, G., Bossin, L., Kranz-Bartz, M., Wen, X., Schmidt, C., Herman, F., Ogata, M., and Sueoka, S.: ESR-thermochronometry of the MIZ1 borehole, Tono, Japan, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15502, https://doi.org/10.5194/egusphere-egu25-15502, 2025.

During orogenesis the initial asymmetry of subduction induces asymmetry of continental collision regarding collisional structure, slab geometries, partitioning of crustal shortening and eventually indentation of a stiffer and cooler continent into a relatively warmer and softer continent. After collision and indentation, extrusion and exhumation of deep metamorphic and plutonic rocks are diagnostic processes to evaluate the extent of asymmetry and the long-term structural evolution along and across the continental suture.

An excellent place to study such highly asymmetric patterns are the distinctly non-cylindrical European Alps, an archetypal example of indentation. There, indentation of relatively stiff Adriatic lower crust and upper mantle into the weaker continental Eurasian plate led to unroofing of the Penninic Lepontine dome, as well as strike-slip motion along the Insubric Line. Late-stage collision led to a highly asymmetric exhumation pattern with relative vertical displacement across the fault in the range of 15 (±5) km. The brittle faulting and exhumation history has so far received only little attention, and particularly S of the Insubric Line, large-scale interpretations of cooling and exhumation are based on very little quantitative knowledge. Exploring the faulting and exhumation history of this suture by applying multiple geo- and thermochronometers spanning temperatures from ca. 50 to 450 °C on both sides of the fault is the focus of this project.

(U-Th)/He apatite and zircon dating on more than 50 samples and fission track dating on 25 samples was applied along densely spaced horizontal as well as vertical transects across the Insubric Line. (U-Th)/He apatite ages, which monitor cooling below ca. 80 °C, from north of the fault line prominently cluster around 8-12 Ma. Apatite fission track (closure temperature of ca. 110 °C) as well as zircon (U-Th)/He ages (ca. 210 °C) are only slightly older. Modelling these thermochronological data point to a Late Miocene phase of more pronounced cooling and exhumation of the Lepontine dome than previously assumed. Thermochronological data of Southalpine samples from the immediate vicinity of the fault line record a similar cooling pulse, indicating either joint late-stage exhumation or a heating pulse invoking resetting of Southalpine units due to Lepontine updoming. U-Pb apatite data, recording higher temperature cooling below ca. 450 °C clearly diverge, yielding Permian ages in the south but Oligocene to Early Miocene ages in the north.

Additionally, the seismotectonic evolution of the Insubric fault is targeted by U-Pb dating on pseudotachylites and mylonites. This methodically new approach yields ages clustering at 30 and 16 Ma for a Southalpine pseudotachylite. The signal was measured for a fine-grained mineral assemblage containing U-bearing phases such as apatite, epidote and titanite. The older age cluster corresponds to the phase of major Lepontine updoming, which we confirmed by mylonite dating. The younger age is in line with published Ar-Ar pseudotachylite data (Müller et al., 2001). These initial data suggest that this method could be a valuable tool for dating palaeoseismic events.

Müller, W., et al. (2001). Geochronological constraints on the evolution of the Periadriatic Fault System (Alps). Int J Earth Sci, 90(3), 623-653.

How to cite: Heberer, B., Rahn, M., Gerdes, A., Holzner, E., Czepl, A., Neubauer, F., Dunkl, I., and von Hagke, C.: Assessing the 4-D evolution along and across the Insubric Line in the European Central Alps using a multi-method geo- and thermochronological approach, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16051, https://doi.org/10.5194/egusphere-egu25-16051, 2025.

The North China Craton (NCC) is the oldest block in eastern China. Since it cratonized during the Paleoproterozoic, the NCC experienced a stable tectonic period during the Paleozoic. During the Meso-Cenozoic, the NCC was influenced by three tectonic domains (the Paleo Asian, the Paleo Tethys and the Pacific Ocean). During that time, the NCC experienced multiple deformation events associated with the Indosinian, Yanshannian and Himalayan orogeny. During the Yanshannian phase, the NCC experienced  lithospheric thinning and destruction. This was potentially associated with the formation of a plateau surface with a mean elevation of approximately 2000 m. However, Jurassic-Cretaceous basins with sediment thickness reaching up to 2000 meters, and the coal-bearing strata of Jurassic indicate that the NCC was at low elevations and humid climate at that time. 
The Luxi terrane is a basement high located in the middle of the eastern NCC surrounded by basins. It composed of the Archean and Proterozoic metamorphic basement, Paleozoic, Mesozoic and Cenozoic strata. We can directly observe the unconformity contact between Carboniferous and Jurassic, Lower Cretaceous and Upper Paleogene. Thus, Luxi terrane is an ideal place to study the tectonic geomorphology evolution in eastern NCC during the Meso-Cenozoic. 
In order to understand the evolution of the eastern NCC during the Meso-Cenozoic, we selected 5 sampling transects perpendicular to the NW trend tectonic line to collect samples in different elevation for low temperature thermochronology experiments including apatite fission track and apatite (U-Th)/He dating. Combined with detrital provenance analysis and structural analysis, we reconstruct the time-temperature history of the NCC
First apatite fission track results indicate early Jurassic uplift of the NCC. Moreover, based on track length analyses and time-temperature modeling, we show that the samples were subject to elevated temperatures between 160 and 100 Ma. Second, results show that the region was subject to a long-wavelength exhumation phase at approximately 100 Ma. After that, our results indicate a rapid uplift event during the Cenozoic, but the farther north the sample located, this uplift occurred more earlier and slower. 

How to cite: Zhou, Q., von Hagke, C., Liu, Y., Guan, Q., Liu, B., Yuan, J., Chen, Y., Zhou, Z., and Du, R.: Mesozoic to Cenozoic denudation and uplift process in Luxi Terrane, North China Craton, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16752, https://doi.org/10.5194/egusphere-egu25-16752, 2025.

Constraining the topographic impact of Quaternary glaciation in the European Alps is important to better assess the control of climate on mountain erosion rates over 10⁴-10⁶ yr timescales. Infra-red stimulated luminescence (IRSL) in feldspar is a dating technique that allows quantification of trapped electrons and the potential reconstruction of rock thermal histories over a timescale of 10⁴-10⁵ years. During the cooling of rocks, ionizing radiation leads to the temporary trapping of electrons in crystal defects. The rate of electron release from these traps depends on the traps’ thermal activation energy as well as their spatial density (controlling their purely athermal loss via quantum mechanical tunnelling). However, interpreting luminescence signals requires that the electron trapping and detrapping models correctly replicate well-constrained thermal histories, both in the laboratory and natural environments. Existing models, such as single saturating exponential (SSE) and general-order kinetics (GOK) for trapping, and band-tail states (BTS) for detrapping, have been previously tested and validated for some benchmark areas. However, these models appear inadequate for our new experimental K-feldspar IRSL dataset from the Mont-Blanc massif (European Alps), e.g. by misfitting laboratory trapping-detrapping behaviour (SSE + BTS) or failing to reproduce dose-dependent isothermal decay curves (GOK). To address these limitations, we introduce a new trapping-detrapping model consisting of a log-normal distribution of trap characteristic doses (D₀ values) and of their thermal lifetimes. This model is internally consistent, mathematically in line with former approaches, verifiable on existing IRSL results from the KTB-borehole, and demonstrates excellent predictive capabilities with respect to our Mont-Blanc dataset. Using this model, we investigated the last 100-kyr cooling history of nine samples from the Mont-Blanc tunnel. Our results suggest that the subsurface cooled by approximately 10–30 °C over the past 20 kyr, implying a potential link to the last deglaciation relating to (1) valley incision and/or (2) cold water infiltration provided by melting glaciers.

How to cite: Bernard, M., Lambert, R., King, G., Guralnik, B., Herman, F., Valla, P., and Schmidt, C.: Infra-red stimulated luminescence on K-feldspar: evaluation of a new trapping-detrapping model and perspectives on the late-stage cooling history of the Mont-Blanc massif, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17069, https://doi.org/10.5194/egusphere-egu25-17069, 2025.

The topography of mountain belts results from complex variations and interactions between tectonic, climatic and erosional processes. In particular, glaciations result in heterogenous incision along and across mountain valleys. The European Alps have been periodically extensively glaciated since the late Pliocene-Quaternary; however, the impact of these glaciations on the evolution of both orogen-scale and valley-scale relief development and erosion remains disputed. One reason for that is the lack of temporal resolution on timescales of 10⁵ to 10⁶ years.

The low-temperature apatite (U-Th)/He (AHe) thermochronometric system is sensitive to the past shape of the near-surface 65 to 85 °C isotherm, which, at a corresponding depth of ∼2 to 4 km below the surface, follows the approximate shape of the landscape at the time. This feature allows deriving the evolution of topography following the time that rock samples cooled through the isotherm. Thus, provided a well understood tectonic rock-uplift history and suitably distributed ages covering the Pliocene-Quaternary period, AHe data can be used to model the glacial impact on mountain morphology.

The Tauern Window in the Eastern European Alps presents an ideal natural laboratory for this approach, as (1) its rapid tectonically driven exhumation until ~8 Ma is well documented in literature, and (2) there is clear glacial overprinting and relatively high relief within its valleys. Here, we present four new AHe elevation profiles along valleys of differing sizes and orientations in the Western Tauern Window, with AHe ages ranging from ~1.4 to 18.2 Ma.

AHe ages generally increase with elevation, with a prominent and rapid Pliocene-Quaternary exhumation signal recorded in the thermal histories of the valley bottom samples only. We interpret this to signify that regional tectonics alone cannot explain the full exhumation history of the region. We further test this hypothesis, using 3D thermo-kinematic inverse modelling in PecubeGUI to quantify the timing and amount of focused glacial valley deepening.  These models are also used to predict the youngest thermal history information, or “edge age”, that we can expect when using the higher-resolution apatite ⁴He/³He methodology in this area in the future.

How to cite: Wapenhans, I., van der Beek, P., Colleps, C., Bernard, M., Gong, L., and Amalberti, J.: Modelling Pliocene-Quaternary landscape evolution recorded by low-temperature thermochronology in the glacially overprinted Tauern Window, Eastern European Alps, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17327, https://doi.org/10.5194/egusphere-egu25-17327, 2025.

Throughout the Cenozoic, the rock uplift of the Calabrian Arc has been strongly influenced by the retreat of the Ionian slab, where a rollback subduction process has been ongoing since Paleogene times. This complex geological setting has resulted in diverse geodynamic processes, including active extension, mantle dynamics, and the potential influence of slab tearing contributing to the uplift of the Calabrian Arc. Within this geodynamic setting, the topography of the Sila Massif is characterized by an exceptional combination of high elevation and an extensive plateau surface. Such landforms represent strong evidence for recent uplift that has not been fully compensated by erosion. This, along with the possible influence of an underlying tear fault, provides a crucial window into the complex interplay between subduction-controlled tectonics, uplift and erosional response.

Here, we used (U-Th)/He low-temperature thermochronology to investigate the cooling history of the Sila Massif, aiming to constrain the timing and rates of exhumation and thereby elucidate the dominant drivers of exhumation. Our preliminary results reveal higher and potentially more variable long-term erosion rates since the Mid-Miocene than the previously estimated 0.1 km/Myr. These elevated exhumation rates require re-evaluating the dominant tectonic drivers within the Calabrian Arc.

By analyzing the spatial and temporal patterns of exhumation derived from our thermochronological data, we can evaluate the relative contributions of different tectonic processes. Here, we discuss the influence of the Catanzaro deep-seated fault in correlation to the disparate evolution of the Sila Massif and the rest of the Calabrian Arc. Our findings provide a new perspective on the influence of deep-seated faults in sculpting the landscape and shaping the evolution of the Calabrian Arc.

How to cite: Villamizar-Escalante, N., von Hagke, C., Friedrichs, B., Heberer, B., Dremel, F., Jörg, R., Gallen, S., and Roda-Boluda, D.: Deciphering the cooling history of the Sila Massif: Insights into the Calabrian Arc tectonic drivers, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18329, https://doi.org/10.5194/egusphere-egu25-18329, 2025.

The tectonic evolution of orogenic systems, such as the Himalayas, has been extensively studied using thermochronometers sensitive to temperatures above 120 °C. Landscape modelling and the inversion of these data provide estimates of deformation rates over timescales of millions of years and spatial scales of tens to hundreds of kilometres. For the Himalayas, these data generally support a Quaternary tectonic scenario dominated by duplexing, where the collision between the Indian and Eurasian plates is accommodated along the active Main Himalayan Thrust (MHT), expressed at the surface as the Main Frontal Thrust (MFT) at the southern front of the Himalayan range. With this model, the observed exhumation of the High Himalayas is driven by underplating beneath the topographic transition, which creates duplex structures and overthrusting. However, several studies challenge this model, highlighting the scarcity of data constraining deformation rates in the Lesser Himalayas, and the absence of thermochronometric data for recent (< 2 Ma) movements.

Trapped-charge thermochronometry, sensitive to ultra-low temperatures below 100 °C, offers new constraints on the final stages of exhumation of the Himalayas (last few kilometres), constraining rates of deformation on sub-Quaternary timescales. Analysis of trapped charge thermochronometry data (luminescence and electron spin resonance) indicate that the MFT has accommodated at least 62 % of the convergence since 200 ka, while also revealing localized fault activity within the Sub-Himalayan fold-and-thrust belt, suggesting strain partitioning. High exhumation rates in the Main Central Thrust (MCT) area, along with differing apparent ages and exhumation rates on each side of the MCT fault system during the late Quaternary point to potential out-of-sequence fault activity, challenging the in-sequence/duplexing model proposed by higher temperature thermochronometers. However, these findings alone cannot definitively favour one tectonic model over another, and further investigation through fault kinematics and landscape modeling is required.

To address this, we employ a 3-D thermo-kinematic landscape evolution model (Pecube), and perform a formal nonlinear inversion using the Neighborhood Algorithm. This approach couples a landscape evolution model with 2-D thermo-kinematic models to simulate regional landscape evolution of the Nepal Himalayas, assessing how different kinematics can explain the morphology of the region. By combining fault geometries, vertical and horizontal displacement trajectories, and surface processes simulations, we will differentiate between the in-sequence/duplexing and out-of-sequence deformation modes for the Quaternary period. This integrated modeling framework will help identify the relative roles of tectonics, climate, and geology in shaping the exhumation patterns in the foreland and hinterland, as well as across different valleys in Nepal. Ultimately, the thermo-kinematic model will also provide insights into the seismic behaviour of the Nepalese mountain belt during the Quaternary.

How to cite: Bouscary, C., Tsukamoto, S., and Braun, J.: Modelling central Nepal Himalayan tectonic from different temperature thermochronometers, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19499, https://doi.org/10.5194/egusphere-egu25-19499, 2025.

Subglacial environments are hotspots for chemical weathering with dynamic hydrological and microbial systems interacting with freshly produced meltwater and sediments. These chemical weathering processes can either drawdown or release atmospheric CO₂ depending on the type and extent of weathering pathways. This study delves into chemical weathering processes in subglacial environments and their broader implications for global geochemical cycling.

We employ meteoric ¹⁰Be, a cosmogenic nuclide, to assess the neoformation of silicate weathering products as the isotope can be incorporated into the crystal structure of clays, oxides, and oxyhydroxides. This study aims to determine the extent to which chemical weathering products within glacial sediments originated during the glacial period, distinguishing them from detrital minerals derived from underlying bedrock and modern soil formed in interglacial settings. Additionally, we aim to address an observational gap in the meteoric ¹⁰Be fallout measurements in the 50° – 70° latitude and high altitude. i.e., northern Britain and Ladakh respectively, thereby enhancing our understanding of the general distribution and behaviour of the isotope.­­­­

We measured the contemporary fallout rates from the upper horizon of moraines in glacial sediments, while the inherited portion of meteoric ¹⁰Be within the lower horizons serve as archives of sub-glacial and proglacial weathering processes. Sequential extractions were performed to quantify extent of chemical weathering by isolating and measuring meteoric ¹⁰Be in three forms: adsorbed in aqueous solution, precipitated with oxides/oxyhydroxides, and/or inside the crystal structure of authigenic clay minerals. The distribution of the isotope was assessed across different grain sizes to examine its dependence on grain size and its association with various chemical and mineral species examined through ICP-MS and XRD.

This is a novel approach to identify minerals of subglacial origin in post-glacial settings. The quantification of the abundance of synglacial silicate weathering products in these glacial sediments will allow inference to a chemical weathering rate under the British Ice Sheet – a heretofore unsolved problem that offers crucial insights into the effect of glaciation on climate dynamics.

How to cite: Kapil, A. N., Telling, J., Carracedo, A., Ersek, V., and Graly, J.: Meteoric 10Be as a Tracer of Chemical Weathering in Glacial Sediments, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-922, https://doi.org/10.5194/egusphere-egu25-922, 2025.

We present new opportunities for modeling cosmogenic isotopes using the chemistry-climate model (CCM) SOCOL, including recent advancements in the modeling of ¹⁰Be and ¹⁴C. A state-of-the-art SOCOL-AERv2 model (coupled with the CRAC production model) has been developed to simulate cosmogenic isotope atmospheric transport and deposition. The model incorporates all relevant atmospheric processes, enabling precise calculations of isotope concentrations across different locations and times. 
Validation of SOCOL-AERv2-Be against ¹⁰Be data from five Antarctic and Greenland ice cores demonstrates a reasonable agreement, capturing large-scale atmospheric dynamics while averaging synoptic-scale variability. This work reveals that most ¹⁰Be production occurs in the stratosphere, with >60% of ¹⁰Be deposited on the Earth's surface within a year. Additionally, a simplified parameterization of the full-model results is introduced, offering quick and practical estimates for polar regions. 
Extending these capabilities, the new SOCOL:14C-Ex model allows for the study of extreme solar particle events (ESPEs) beyond the Holocene based on ¹⁴C, which was previously limited by the lack of models applicable to glacial climates. Using this model we analyzed the strongest known ESPE, dated to approximately 12350 BC. This event, nearly twice as powerful as the widely studied 775 AD event, likely occurred between January and April 12350 BC, with a peak in early March. 
These developments demonstrate how advanced chemistry-climate modeling with the SOCOL framework opens new frontiers in understanding cosmogenic isotopes, solar-terrestrial interactions, and the climatic implications of extreme solar events.

How to cite: Golubenko, K., Rozanov, E., Baroni, M., and Usoskin, I.: New Opportunities for Modeling Cosmogenic Isotopes Using the Chemistry-Climate Model SOCOL , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1711, https://doi.org/10.5194/egusphere-egu25-1711, 2025.

Beryllium isotopes, i.e. cosmogenic meteoric ¹⁰Be and stable ⁹Be, enter the oceans through distinct pathways. Beryllium-10 is produced in the atmosphere and enters the oceans mainly via precipitation, while ⁹Be is sourced from continents. Beryllium isotopes with a short oceanic residence time (10²-10³ yrs) display non-conservative behaviour in seawater. The ¹⁰Be/⁹Be proxy has been utilized as a powerful tool for quantifying diverse processes, including geomagnetism, sedimentation, continental input, and ocean circulation. Substantial effort has been invested in understanding external sources and internal cycling of Be isotopes in the recent decade, such as constraints on the global distribution of ¹⁰Be depositional fluxes and on riverine and benthic ⁹Be inputs. Hence, it offers an excellent opportunity to revisit their modern oceanic cycle. Here, we investigate the controls on the modern oceanic cycling of Be isotopes using a three-dimensional ocean biogeochemical model constrained by water-column distributions of ⁹Be and ¹⁰Be compiled from the literature. In addition to modelling the previously identified controls, we highlight the critical role of marine benthic fluxes and scavenging on particulate organic matter and opal in governing the mass balance and spatial distribution of Be isotopes. The transport of Be isotopes between basins by circulation is of lesser importance compared to external inputs at continent/atmosphere–ocean boundaries, except in the South Pacific. Consequently, the basin-wide ¹⁰Be/⁹Be ratio predominantly reflects the pattern of external inputs across most basins in the modern ocean. Based on our data-constrained oceanic model, we can further assess the sensitivity of basin-wide ¹⁰Be/⁹Be ratios to changes in external sources, such as continental denudation, and internal cycling, such as particle scavenging. The mechanistic understanding developed from this Be cycling model provides important insights into the various applications of marine Be isotopes, and offers additional tools to assess the individual effects of geomagnetism and environment on cosmogenic ¹⁰Be/⁹Be records in marine sediments.

How to cite: Deng, K., de Souza, G., and Du, J.: Modelling the modern oceanic cycle of beryllium-10 and beryllium-9, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2277, https://doi.org/10.5194/egusphere-egu25-2277, 2025.

Measurements of the cosmogenic isotope concentrations in the natural archives are valuable sources of information about the variability of solar activity and parameters of explosive events in the solar system and our galaxy. The retrieval and understanding of the forcing peculiarities from the data requires detailed modeling of all relevant processes. Therefore, any applied model should be able to treat the production, transport, chemical transformation, and deposition of cosmogenic isotopes and atmospheric state parameters regulating their life cycle. A hierarchy of such models ranging from simple box models to full-scale Erath system models has been developed and utilized since 1990th. This lecture will briefly present the critical turning points in model development. Then I will discuss contemporary approaches to simulate the transport, chemistry, mixing, and deposition of different cosmogenic isotopes produced by galactic cosmic rays and solar proton events and the most promising ways of further development. Special attention will be paid to the influence of volcanic eruptions and integrating ¹⁰Be modeling with other species such as ³⁶Cl and ¹⁴C.

Acknowledgement: Support from Oulu University (Project GERACLIS #24304650) and collaborative Swiss French project AEON (grant no. 200020E_219166).

How to cite: Rozanov, E., Egorova, T., Golubenko, K., Baroni, M., Sukhodolov, T., and Usoskin, I.: An overview of available models for simulations of the life cycle of cosmogenic isotopes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2464, https://doi.org/10.5194/egusphere-egu25-2464, 2025.

Quantifying the rates at which carbonate rocks are denuded, the balance between chemical weathering and physical erosion, and their responsiveness to climate, vegetation, and tectonic activity is crucial for revealing feedback mechanisms in the carbon cycle and the dynamics of karst landscapes that provide vital services to humans. However, no existing method effectively partitions denudation into erosion and weathering fluxes. To estimate total denudation rates in carbonate terrains across spatial scales from soil to entire watersheds, we adapted a previously established framework that utilizes cosmogenic meteoric ¹⁰Be as an atmospheric flux tracer together with stable ⁹Be released during rock weathering. We employed the new method to the limestone-rich French Jura Mountains. By analyzing water, soil, sediment, travertine, and bedrock for ¹⁰Be/⁹Be ratios, as well as major and trace elements, stable carbon isotopes, and radiogenic strontium, we were able to quantify the contributions of beryllium from both primary and secondary carbonate phases and its release during the weathering of carbonate bedrock versus silicate impurities. We determined the partitioning of beryllium between solids and solutions and calculated rates of catchment-wide denudation (from sediment) and point source denudation (from soil), along with weathering and erosion rates. Our findings suggest that the average denudation rates range from 300 to 500 t/km²/yr, with denudation primarily driven by weathering intensity (W/D) ratios exceeding 0.92. These rates are consistent within a factor of two when compared to decadal-scale denudation rates derived from combined suspended and dissolved fluxes, underscoring the substantial potential of this method for Earth surface research in karst landscapes.

How to cite: Wittmann, H., Bouchez, J., Calmels, D., Gaillardet, J., Frick, D., Keddadouche, K., Aumaitre, G., Zaidi, F., and von Blanckenburg, F.: Denudation and weathering rates of carbonate landscapes from meteoric 10Be/9Be ratios, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3110, https://doi.org/10.5194/egusphere-egu25-3110, 2025.

Weathering of volcanic rocks accounts for approximately one third of global CO₂ consumption in the silicate weathering cycle¹. Tropical volcanic islands contribute to this process due to their extreme denudation rates, thought to be mainly driven by high and episodic precipitation, which may sustain high weathering fluxes. However, how total denudation (D) divides into erosion (E) and weathering (W) fluxes, and the factors governing their long-term rates on tropical islands remain unclear. This uncertainty arises from the lack of methods to quantify these rates over centennial to millennial timescales. Common approaches face challenges like absence of quartz for in situ-¹⁰Be or unevenly-distributed olivine for in situ-³He analysis, limited long-term observational data for gauging, and the impacts of caldera collapse and infilling of river valleys from eruptions that complicate erosion rate estimates from topographic reconstructions. The recently developed meteoric ¹⁰Be/⁹Be ratio that uses meteoric ¹⁰Be as an atmospheric flux tracer alongside stable ⁹Be released during rock weathering provides an alternative to estimate D and weathering intensity across scales, from soils to entire watersheds, independent of specific minerals.

We applied this method to Réunion and Guadeloupe, two islands with extreme precipitation regimes (respectively up to 11000 and 8000 mm/yr), steep slopes, high elevations, and warm mean annual temperatures. Both islands have catchments on lavas of similar emplacement ages (5 Kyr to 1.8 Myr), but differ mainly in lithology: Réunion's hotspot volcanism produces basalts, whereas Guadeloupe's arc volcanism generates mainly andesites. To isolate key controlling parameters, we sampled catchments with uniform lava deposition ages across varying precipitation regimes.

Preliminary results reveal a stark contrast in denudation (D). On Réunion, catchment-averaged D´s are 4000 t/km²/yr (n=11, ranging from 11 t/km²/yr in very small catchments to 15000 t/km²/yr), while Guadeloupe´s average D is 300 t/km²/yr (n=13, ranging from 100 to 1000 t/km²/yr). Weathering intensities measured on sediment from Guadeloupe are, on average, significantly higher than for Reunion. This result aligns with the observation that lower erosion rates promote more intensive soil leaching. Our denudation rates generally align well with gauging-based rates^2,3and topographic reconstructions^4,5,6, although the latter estimates are consistently higher by a factor of 2-5, depending on each island.

Our preliminary findings suggest that volcanic emplacement age does not control D, while the role of lithology requires further investigation. Future work will involve determining local depositional fluxes of meteoric ¹⁰Be, and analyzing additional data from weathering profiles and river sediments.

References : 1. Dessert et al., 2003; 2. Louvat et al., 1997 ; 3. Rad et al., 2006 ; 4. Salvany et al., 2012; 5. Gayer et al., 2019; 6. Samper et al., 2007.

How to cite: folch, A., Rowald, L., Bouchez, J., Gayer, E., Dessert, C., Bernhardt, A., and Wittmann, H.: Insights on Denudation Controls of Volcanic Tropical Islands from Meteoric 10Be/9Be Ratios, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6701, https://doi.org/10.5194/egusphere-egu25-6701, 2025.

The timing, amplitude, and mechanisms of rapid climate changes since the last deglaciation remain elusive. Here we present well dated, high resolution lacustrine sediment ¹⁰Be/⁹Be ratio and major elements records of East Asia’s climate variability from Maar Lake Xiaolongwan, Northeast China. The abrupt increase in concentrations of Al, Ca, and Ti, considered proxies for aeolian dust flux, intriguingly coincides with a significant enhancement of the East Asian summer monsoon since the onset of the Bølling-Allerød interstadial. Combining previous analyses of dust provenance, we argue that this pattern likely attributes to heightened Central Asian dust input driven by winter-spring southwest winds and increased precipitation controlled by summer monsoon. The abrupt vegetation prosperity at the beginning of the Holocene Optimum, as evidenced by an increase in total organic carbon and total nitrogen, could have reduced the concentration of Mg, Fe, Al, and ⁹Be derived from the weathering of surrounding basaltic bedrock. The identified abrupt decreases in precipitation in northeastern China, inferred from our ¹⁰Be/⁹Be precipitation proxy, are consistent with known Dansgaard-Oeschger and Bond events in the North Atlantic region since the last deglaciation. This supports that global cooling events since the last deglaciation may be linked to a complex interplay between the intertropical convergence zone, El Niño events, and the Atlantic meridional overturning circulation.

How to cite: Yang, Y., Xu, S., Cao, Z.-P., and Liu, C.-Q.: Authigenic beryllium isotopes in maar lake sediments response to climate change since the last deglaciation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7851, https://doi.org/10.5194/egusphere-egu25-7851, 2025.

How to cite: Schanner, M. A., Nilsson, A., and Muscheler, R.: Thermoremanent magnetic, 10Be and 14C data provide no convincing evidence for longterm solar variability in the Holocene, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10115, https://doi.org/10.5194/egusphere-egu25-10115, 2025.

Galactic cosmic rays constantly bombard the Earth’s atmosphere and induce cascades of nuclear reactions that produce various particles. One of the products of such interactions is cosmogenic nuclides, very useful tools for researches in different areas, such as solar physics, atmospheric physics, geomagnetic studies, hydrology, archeology, and many others. Their production rates are not uniform over the globe. Due to the changing shielding effect of the Earth’s geomagnetic field from cosmic rays, the production is higher in polar regions than near the equator. Furthermore, the production of cosmogenic nuclides varies greatly with altitude. In addition, the cosmic ray flux changes over time, following variations in solar activity. Several production models are available that account for all these effects (Poluianov et al., 2016, 2020), but their use requires some learning of computational details. To simplify the application of these models, we present calculated time series of the production rates for ³H, ⁷Be, ¹⁰Be, ¹⁴C, ²²Na, and ³⁶Cl, covering more than a century up to the present day. The results provide altitude-longitude-latitude resolution for each nuclide, include recent cosmic-ray data for the beginning of the 20th century, and account for the slow evolution of the geomagnetic field.

How to cite: Poluianov, S., Kovaltsov, G., Usoskin, I., and Kurita, N.: Production rates of atmospheric cosmogenic nuclides 3H, 7Be, 10Be, 14C, 22Na, 36Cl calculated for the 20th and early 21st centuries, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12244, https://doi.org/10.5194/egusphere-egu25-12244, 2025.

Cosmogenic nuclides are invaluable tools for quantifying denudation and uplift rates and thus decoding geological processes that act over different timescales and leave distinct imprints on the Earth’s surface. Among these, meteoric ¹⁰Be has emerged as a particularly powerful proxy due to its unique capability of being measured independently of lithology. Meteoric ¹⁰Be is an atmospheric flux tracer, and when normalized to stable ⁹Be, a trace element released by rocks during weathering, the ¹⁰Be/⁹Be ratio emerges. This ratio can be measured on small sample amounts and is independent of the presence of quartz which provides a benefit over the “sister” nuclide in situ ¹⁰Be that has been widely used in landscapes of felsic rocks.

The Albanides orogenic belt is a tectonically active region characterised by a remarkable lithological diversity, including carbonates, ophiolites, siliciclastics, metamorphics, and volcanic rocks distributed over short distances. In the Albanides´quartz-bearing sector, in situ ¹⁰Be-derived denudation rates were recently measured, but large areas of this belt remained unexplored due to lack of quartz. Meteoric ¹⁰Be/⁹Be -derived denudation rates fill this gap. When combined with geomorphic analyses to investigate uplift patterns in equilibrated river systems, results from both cosmogenic nuclides systems are consistent, and reveal significant spatial variability in denudation and uplift rates ranging from 0.1 to over 1.5 mm/yr. These results suggest that the Albanides are undergoing rapid landscape evolution, with rates and uplift mechanisms varying considerably across the belt. Our findings underscore the versatility of the meteoric ¹⁰Be/⁹Be method as a robust approach providing key information for quantifying erosional processes, sediment transport dynamics, landscape development and tectonic evolution. The consistency between the two datasets strengthens the reliability of the meteoric ¹⁰Be/⁹Be technique across regions with diverse geological compositions. Overall, our approach paves the way for future studies aimed at exploring the interplay between tectonics, climate, and surface processes using cosmogenic nuclides in complex lithological settings.

How to cite: Bazzucchi, C., Wittmann, H., Crosetto, S., Ballato, P., Faccenna, C., and Rossetti, F.: Meteoric 10Be/9Be as a Proxy for Denudation and Uplift in the active Albanides orogenic belt, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13118, https://doi.org/10.5194/egusphere-egu25-13118, 2025.

We investigate the coupling of concentrations of the cosmogenic radionuclide Be-7 (time series of activity concentration of Be-7 in aerosols evaluated by the corresponding activity in aerosols on a weekly basis at the National Radiation Protection Institute Monitoring Section in Prague) with reliable indicators of various atmospheric processes primarily determined by the solar activity level and space weather conditions influenced by coupling processes between the neutral atmosphere, ionosphere including sporadic E layers, magnetosphere and other geospace environment. We try to contribute to better understanding of the dynamics of these processes by associating them with new catalogue of over two hundred geomagnetic storms initiated by co-rotating Interaction Region (CIR)/High-Speed solar wind Stream (HSSWS) during the years 2016 – 2023. The catalogue CIR/HSSWS allows analysis of geomagnetic storms effects on ionosphere and troposphere which were clearly caused by CIR/HSSWS and or sudden stratospheric warmings or various significant tropospheric events like convection associated with frontal passages over European region. We also compare Be-7 concentrations during periods of strong solar and geomagnetic storms with periods of low solar activity in the longitudinal view in years 1986 – 2023.

How to cite: Podolská, K., Kozubek, M., Hýža, M., and Šindelářová, T.: Concentrations of Be-7 cosmogenic radionuclide in aerosols in connection with geomagnetic storms of CIR/HSSWS origin with atmospheric influences., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14118, https://doi.org/10.5194/egusphere-egu25-14118, 2025.

Perched precariously upon the deepest continental location on Earth, East Antarctica’s Denman Glacier is hypersensitive to changes in both air and ocean temperatures. Shackleton Ice Shelf buttresses Denman Glacier, regulating the rate at which it flows into the Southern Ocean. However, under warming ocean conditions along the continental shelf – a function of increased upwelling of warm Circumpolar Deep Water (CDW) in many places around Antarctica – Shackleton Ice Shelf may become unstable and collapse. Loss of the ice shelf would destabilise the glacier in turn, and a complete collapse of the Denman System could contribute +1.5 m to global sea level. Besides what began 15 years ago, observational ocean data show that the interactions between upwelling CDW and regional calving margins is otherwise unprecedented in historical records, and of unknown influence on longer timescales. Here we aim to resolve two questions: is warm CDW currently reaching the glacier’s grounding line? And is there any evidence of CDW presence within the Shackleton Ice Shelf on a Holocene timescale? Utilising a Conductivity-Temperature-Depth (CTD) profile and a 1m sediment core collected from the seafloor beneath Shackleton Ice Shelf during the 2023-24 Denman Terrestrial Campaign, we employ meteoric-¹⁰Be signatures from sediment samples – which have been shown to reflect upwelling circumpolar deep-water conditions along the Antarctic continental shelf – to discuss the modern and paleo-ocean conditions within the Shackleton Ice Shelf cavity.

How to cite: Jeromson, M., Husdell, M., Bostock, H., Fink, D., Simon, K., Rieke, O., Thompson, S., Rosevear, M., Nothdurft, L., Herraiz–Borreguero, L., and White, D.: An assessment of modern and past Circumpolar Deep Water presence beneath Shackleton Ice Shelf, East Antarctica: insights into using Meteoric Beryllium-10, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15088, https://doi.org/10.5194/egusphere-egu25-15088, 2025.

Meteoric beryllium-10 (¹⁰Be_m) is a valuable tracer for investigating land surface processes, and numerous studies have used it to assess soil ages and residence time, date sedimentary archives and quantify soil erosion rates at the hillslope and catchment scales. The flux of ¹⁰Be_m to the Earth's surface is influenced by e.g. solar activity, the Earth’s magnetic field, stratosphere-troposphere exchange dynamics and atmospheric circulation patterns that control ¹⁰Be_m production, transport, and deposition.

The control of precipitation on the flux of ¹⁰Be_m to Earth’s surface remains unclear at low latitude, where there is little observational data available. To study the impact of precipitation on deposition of ¹⁰Be_m at low latitude, we determined ¹⁰Be_m concentrations in rainwater along a 10-fold precipitation gradient on Santa Cruz Island in the Galápagos Archipelago (Ecuador) over one meteorological year. To elucidate spatial and temporal variations in ¹⁰Be_m concentrations, rainwater was collected at five sites spanning the precipitation gradient during the cool and warm seasons.

Our findings reveal a rise in ¹⁰Be_m deposition rates with precipitation that exceeds a linear increase, indicating a super-additive effect of precipitation on ¹⁰Be_m deposition. We attribute this to the presence of an inversion layer on Santa Cruz Island during the cool season, which limits atmospheric mixing. Furthermore, we observed a clear decline in ¹⁰Be_m concentrations with increased convective precipitation during the warm and rainy season. This suggests a dilution effect on atmospheric ¹⁰Be_m deposition during intense precipitation events. Our study highlights the spatial variability of ¹⁰Be_m deposition along a precipitation gradient and deepens understanding of how different types of precipitation influence ¹⁰Be_m fluxes.

How to cite: Paque, R., Moore, A., Dixon, J., Montes, Y., Christl, M., and Vanacker, V.: Orographic and convective precipitation control meteoric 10Be wet depositional fluxes at low latitude, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15588, https://doi.org/10.5194/egusphere-egu25-15588, 2025.

We investigated chemical weathering in the subglacial environment of East Antarctica through studies of two isotope systems: meteoric ¹⁰Be and (²³⁴U/²³⁸U). We sampled blue ice moraines as a window into Antarctica’s subglacial environments. Here vapour-starved winds ablate near-stagnant ice, allowing sediment-rich basal ice to be thrust against mountains and nunataks. These moraines form across a wide swath of the continent. Many blue ice moraine sediments are substantially altered by chemical weathering; sediment grains are often coated in a mix of clays, oxides, and amorphous material that does not resemble soil but speaks to a chemical weathering regime specially found in the subglacial environment.

Meteoric ¹⁰Be works as a tracer in this system because its concentration in ice is relatively well known from ice cores, it is very unlikely to occur in detrital minerals, and it has a strong propensity to become incorporated in authigenic minerals, such as clays and oxyhydroxides. The total abundance of meteoric ¹⁰Be therefore traces meltwater input over the sediment residence time and the speciation of meteoric ¹⁰Be traces the formation of authigenic minerals.

In developing the meteoric ¹⁰Be tracer, we initially focused on Mt. Achernar Moraine, a site in the central Transantarctic Mountains containing highly weathered fine sediments of subglacial origin. We tested a variety of extraction procedures to most effectively extract ¹⁰Be from minerals formed during chemical weathering. At Mt. Achernar Moraine, the total meteoric ¹⁰Be strongly correlates to the abundance of authigenic minerals (particularly smectite clay) and aligns well with mass balance calculations for meltwater input.