Glaciers distinct from the ice sheets in Greenland and Antarctica are experiencing accelerating retreat. Consequently, landscapes so-far hidden beneath the ice will emerge, yet their characteristics are poorly constrained by existing observations and models. At the same time, the subglacial topography itself controls retreat patterns and magnitudes. Hence, an improved representation of the glacier bed is key for improved future projections of glacier evolution. Here, we present a physically plausible map of subglacial topography for all >200,000 glaciers in the world, called Topography of a Deglaciated Earth (TOPO-DE). The map is constrained by an inverse modeling approach that relies on the higher-order Instructed Glacier Model (IGM), a wealth of surface observations, and automatic Bayesian calibration against thickness observations. We find a global glacier volume of 149±29 × 103 km3 (316±61 mm sea level equivalent) and a mean glacier thickness of 212 m. While the global total is consistent with previous work, regionally variable discrepancies highlight the differences between this study and previous reconstructions based on shallow ice-flow physics. The landscapes beneath the ice are characterized by a large potential to host future lakes, quantified as a combined potential lake volume of >3,000 km3, or 2% of the global glacier volume, and a potential areal lake coverage of the presently ice-covered lands of 6%. We show where previous studies produced unphysical bed features and compare that to solutions of our model. Our freely-available bed product offers new insights into landscapes emerging after glacier retreat and can serve as an input for future projections of glacier change and its consequences.
How to cite: Frank, T., van Pelt, W., Rounce, D., Jouvet, G., and Hock, R.: Beneath the ice: Unravelling the Topography of a Deglaciated Earth (TOPO-DE), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16948, https://doi.org/10.5194/egusphere-egu26-16948, 2026.
Glacier demise is palpable in mountain regions around the world. This retreat affects marine and terrestrial ecosystems, regional year-around water security as well as increases the risk for mountain hazards. Satellite remote sensing techniques have drawn a sinister picture of increasing rates of ice loss, particularly in the European Alps. There, model projections suggest that glaciers will largely disappear from the mountain landscape by the end of the century. Under most optimistic scenarios with a regional warming below ~3°C, one third of the ice volume can be preserved. Only the larger and more elevated ice bodies will survive. Most glaciers will however disappear. Here, we will redraw this picture combining 3D glacier evolution modelling with systematic data assimilation. In this way, a seamless record of glacier evolution in the European Alps is produced, spanning the time period 2000 to 2100 and considering various climate scenarios. Its main asset is that no geometric simplifications are applied as typically done in current tools for regional glacier modelling. Together with inverse and ensemble techniques for data assimilation, our approach can directly ingest map products of observed surface velocities as well as the spatial pattern of the observed 2000-2020 elevation change. For our future projections, we exclusively rely on high-resolution regional climate models, better representing the atmospheric conditions over mountainous.
Our results largely corroborate the above-described grim fate for the European glacier population. The retreat is primarily driven by temperature increase rather than precipitation changes. For the first time, 3D simulations make this retreat tangible in its full extent. Even under the most favourable climatic trajectories, glacier remnants will only survive as isolated ice patches at high altitudes. Like hermits or relicts from the past, they will have largely disappeared from the public perception in Central Europe - at the latest by 2100. We further break down our projections by Alpine sub-regions. We find more pronounced values of relative volume loss in southern and eastern regions (e.g., Rhaetian Alps). Regions with little coverage at present (e.g., Glarus Alps) will virtually become ice-free. Only exception is the French region of the Dauphiné Alps. In general, glaciers in the north-western ranges (Pennine, Bernese, Graian Alps) appear more resilient to future warming – as glacier there can retreat to higher altitudes.
How to cite: Fürst, J. J., Herrmann, O., Groos, A. R., Kc, M., Prasad, V., Sommer, C., and Jouvet, G.: Taking a glimpse into the glacier demise of the European Alps – a 3D portrait, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14057, https://doi.org/10.5194/egusphere-egu26-14057, 2026.
Global glacier mass loss is accelerating, yet considerable spread in projected glacier changes remains due to model structure, forcing, and parameter uncertainty. Most global glacier projections rely on relatively simple models where calibration approaches are essential to constrain uncertainty by using scarce observations. Probabilistic calibration strategies that help with quantifying uncertainities have recently incorporated into a limited number of global glacier models. As a next step, we suggest employing Bayesian data assimilation methods with untapped potential to integrate multi source observations (in-situ, satellite, reanalysis) when calibrating global glacier model projections.
Here, we present a probabilistic calibration framework for the Python Glacier Evolution Model (PyGEM) based on ensemble-based data assimilation. Two data assimilation techniques (PBS and AdaPBS) are used to calibrate mass balance parameters to constrain future projections of glacio-hydrological variables (surface mass balance and runoff) between 2015 and 2100 under four SSP climate scenarios across the Scandinavian region. In this work, we compare our calibration results with commonly used deterministic and probabilistic glacier model calibration algorithms which are already in use in PyGEM. Our probabilistic calibration framework based on data assimilation has the potential to quantify and disentangle uncertainties from climate forcing, model structure, and parameters. Better constrained and uncertainty-aware glacier models increases confidence in projections of future glacier change and their relevant impacts. This work paves the way for producing policy relevant global glacier projections and scenarios with their uncertainty estimates within the ERC-AdG GLACMASS project.
How to cite: Yılmaz, Y. A., Aalstad, K., Guillet, G., Rounce, D., Tober, B., Yang, R., Åkesson, H., and Hock, R.: Probabilistic calibration of glacier projections using data assimilation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14845, https://doi.org/10.5194/egusphere-egu26-14845, 2026.
Wave ogives are among the most striking and least studied glacier surface features. They sometimes form at the bottom of icefalls, yet exactly how they form has eluded scientists for decades. On the Gilkey Glacier, below the Vaughan Lewis Icefall in the Juneau Icefield region of Alaska there is a well-developed series of wave ogives. Our study uses geophysical field observations of the Gilkey Glacier ogives combined with satellite data and modeling to better understand the formation process. Satellite-derived DEMs provide ogive amplitudes of 5-8 m and wavelengths of ~130 m. By combining Global Navigation Satellite System (GNSS), satellite, and timelapse camera-derived velocity observations, we found that the Vaughan Lewis Glacier is significantly slower than the Gilkey Glacier (60 m/yr compared to 130 m/yr), and the icefall is exceptionally fast (~2200 m/yr). We used the velocity and ogive characteristics to constrain parameters in a finite-difference numerical model that simulates ogive formation. Using this model, we tested the plausibility of the two formation mechanisms; i) seasonal mass balance variation; and ii) seasonal velocity variation of the lower glacier. Our results suggest that seasonal velocity variation of the lower glacier is the primary driver in wave ogive formation.
How to cite: Ochwat, N., Terleth, Y., Anderson, R. S., Banwell, A., Truffer, M., Hobson, C., Bidwell, S., Neuhauser, E., and Kaltenborn, J.: Wavering Ways Waves Work: Understanding glacier ogive formation using satellite and field observations combined with modelling, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6984, https://doi.org/10.5194/egusphere-egu26-6984, 2026.
We use a three-dimensional time-dependent glacier model that couples higher-order ice flow dynamics with multi-dimensional englacial and supraglacial debris transport to investigate the behavior of debris-covered glaciers and their response to climate change. By applying the model to a synthetic idealized glacier, our simulations allow for multi-dimensional, physically-based and general insights into debris-ice interactions. The model incorporates a melt-modification parameterization based on a synthesis of Østrem curves from previous debris-covered glacier studies, which is coupled to submodules for the spatio-temporal evolution of debris. The debris submodule also includes an off-glacier debris evacuation scheme which allows our simulations to reach a steady state debris mass, while explicitly ensuring debris mass conservation. Results reveal that the presence of a debris cover significantly alters the steady state glacier geometry and dynamics, as well as its climate change response. Debris-covered glaciers in some specific environmental settings are also found to be prone to the formation of stagnant, isolated dead ice bodies during glacier recession. The results highlight the importance of representing a more complete and multi-dimensional set of key debris processes in debris-covered glacier models, including (i) a melt-modification curve that captures melt enhancement for thin debris, (ii) resolving dynamic debris-ice interactions in three dimensions with higher-order ice flow, (iii) explicitly modelling the multi-dimensional, spatio-temporal evolution of a supra- and englacial debris mass, and (iv) a mass-conserving debris off-loading procedure which allows the model to reach steady state. Our main findings therefore emphasize the need to incorporate robust debris modelling in future glacier projections.
How to cite: Verhaegen, Y. and Huybrechts, P.: Coupling debris transport to 3D higher-order ice flow dynamics to model the behavior and climate change response of debris-covered glaciers, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4500, https://doi.org/10.5194/egusphere-egu26-4500, 2026.
Supraglacial debris partially covers more than 40% of Earth’s glaciers (excluding Antarctica) and, where present, acts as a major controlling factor for glacier melt. It can enhance melt when the layer is thin by reducing surface albedo (increasing the net radiative flux) and it reduces melt when it is thick by insulating the ice from the atmosphere (dampening the conductive heat flux). Accurately simulating the spatio-temporal evolution of debris over a glacier is still a challenge, because of diverse debris sources and mechanisms of transport on and within the ice that affect long-term debris cover evolution. Previous studies have investigated the evolution of debris from geomorphological and historical data or from debris-tracking ice dynamics modelling. These approaches, however, often do not capture the transient ice melt-debris thickness relationship under a changing climate. To date, no attempt has been made to couple the century-scale evolution of debris extent and thickness with a full surface energy-balance model to evaluate debris-melt feedbacks and assess their impacts on catchment-scale runoff generation.
We apply a distributed land surface-energy balance model to simulate the glacier evolution and surface hydrology of the Aletschgletscher catchment (including glaciated and ice-free areas) in the Swiss Alps from 1900 to 2023. We incorporate the evolution of supraglacial debris, constrained using historical topographic maps and recent debris thickness measurements. We evaluate the impact that time-evolving debris-cover extent and thickness has on the glacier mass balance and hydrology. We also compare results for Grosser Aletsch and Oberaletsch to demonstrate that increasing catchment debris cover influences catchment response to climate and glacier change.
Our results show that the contribution of sub-debris melt to runoff varied substantially over the last century. The catchment-wide sub-debris melt contribution increased until ~1945, then declined until today. However, trends differed between subcatchments. In the sparsely debris-covered Grosser Aletschgletscher, sub-debris melt reached its peak around 1940 (25–30% of total ice melt) before decreasing until present (same pattern as the entire catchment). In contrast, the highly debris-covered Oberaletsch shows a continuous increase, with recent values reaching 40–50% without a clear peak. The catchment trend is primarily explained by the evolution of debris cover on Grosser Aletschgletscher, combined with climate factors. Periods of expanding debris extent (~1910–1930 and ~1940–1965) initially increased the sub-debris melt contribution by enlarging the area where melt is enhanced by thin debris. Once debris area stabilised and average thickness increased (post-~1965), the stronger insulating effect reduced its relative contribution. An early rapid thinning of debris (~1910–1920) further enhanced early melt. Furthermore, climate warming has raised the 0°C isotherm, increasing melt in debris-free areas and thereby relatively reducing the proportion of melt occurring under debris. Therefore, the sub-debris melt contribution is affected by the combination between debris evolution and climate change. In a world with darkening glaciers, it is essential for glacio-hydrological models to consider evolving debris extent and thickness, and to incorporate feedbacks related to these changes, which substantially impact the surface energy balance, in order to accurately project future runoff from these catchments.
How to cite: Melo-Velasco, V., Shaw, T., McCarthy, M., Fyffe, C., Miles, E., Muñoz Hermosilla, J. M., Fontrodona-Bach, A., Gantayat, P., Jouberton, A., and Pellicciotti, F.: Glacio-hydrological modelling of the Aletschgletscher catchment with evolving supraglacial debris since 1900, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17501, https://doi.org/10.5194/egusphere-egu26-17501, 2026.
Recent climate warming has increased the extent of debris cover on mountain glaciers. A thicker debris cover tends to shield the glacier surface from melting whereas a thinner/ patchy debris cover can amplify surface melting, with consequences for glacier dynamics and evolution. Most modelling studies that have estimated glacier evolution at a regional scale either a) do not consider the impact of debris cover at all or, b) assume a temporally static debris cover. Some major advances have been achieved in a recent study that accounted for the impact of evolving debris cover on future evolution of glaciers with an aerial extent > 1 km2 in High Mountain Asia; however, limitations remained related to the parameterised relationships between debris cover area and thickness changes. Alternatively, debris-explicit ice flow models exist, but are not suitable for regional or global scales due to the data inputs and spin-up period. As such, a gap exists for an approach to model dynamic debris that is physics-based but simple to implement in large-scale glacier models.
To address this gap, we present a 1D numerical ice-flow model based on the Shallow Ice Approximation (SIA) that includes coupled sub-modules which explicitly evolve the debris cover and thickness using principles of mass conservation and a degree day approach for estimating surface mass balance. It uses freely available data namely ERA-5 daily data of temperature and precipitation, glacier geodetic mass balances, historic satellite-derived supraglacial debris cover, glacier surface elevation and glacier surface velocities as inputs. The debris extent/thickness module is easily calibrated; dependent on the mass balance parameters and does not lead to the problem of equifinality of parameter sets.
We demonstrate the model over four debris-covered glaciers located in the Central European Alps (Oberaletsch, Zmutt, Pasterze and Miage glaciers), where present-day debris thickness data are available. Results from the historic simulations show that the model was able to estimate the distribution of debris thickness within an RMSE ~ 0.07 m. In addition to that, the modelled evolution of the debris cover area fraction (i.e., the fraction of the glacier area covered by debris in a 10-m surface elevation band) was also in good agreement with that measured with maximum RMSE of ~8% per elevation band. The future evolution of these glaciers was carried out by forcing the ice-flow model with CMIP6 derived SSP2-4.5 and SSP5-8.5 climate scenarios, and highlighting the process of tongue detachment from headwall mass supply areas in the 21st century. Future simulations revealed that these test glaciers would be nearly completely covered with debris by the end of the 21st century with debris thicknesses becoming at least twice as compared to the present state. In addition to that, these glaciers are also expected to break into fragments with the tongues getting detached from the main glacier. Overall, the coupled model is easy to apply, computationally fast and is currently being used to study the impact of an evolving debris cover on glacier evolution, in the Central European Alps, under different climate scenarios.
How to cite: Gantayat, P., Miles, E. S., Jouberton, A., Manuel Munoz, J., Melo Velasco, V., Fontrodona Bach, A., McCarthy, M., and Pellicciotti, F.: Modelling the impact of an evolving supraglacial debris cover on the future evolution of glaciers in a changing climate, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19772, https://doi.org/10.5194/egusphere-egu26-19772, 2026.
Debris-covered glaciers play an important role in alpine hydrology, yet the origin and transport pathways of debris within the glacier remain difficult to constrain. This is a major limitation in glacier evolution models, many of which have tended to ignore debris transient effects, especially for assessment of catchment hydrological processes. Supraglacial debris coverage is an integrated signal of debris supply, climate forcing, glacier geometry and debris physical properties, all of which vary in time, resulting in a complex inverse problem for model-based reconstructions.
Here, we apply the Instructed Glacier Model (IGM) with a newly implemented Lagrangian debris transport module combined with an ensemble of climate forcing, to explore constraints on debris input at Oberaletsch Glacier in the Swiss Alps. This framework allows debris particles to be tracked within a dynamically evolving glacier geometry and enables a likelihood-based assessment of inferred debris source regions across the ensemble. Rather than seeking a unique reconstruction, we identify spatially persistent and statistically robust seeding areas that are compatible with the observed historical evolution of debris extent derived from debris-cover maps for 1965, 1985, 1995, 2000, 2010 and 2015. These areas are identified by tracing debris particles backward from their final positions within the observed debris-covered zone to their upstream seeding locations.
Our results show that our inverse filtering strategy effectively identifies potential debris input zones that are primarily controlled by glacier dynamics and geometry. Notably, including or excluding the effect of debris on surface mass balance does not significantly alter the reconstructed debris extent in the ablation zone, highlighting the dominant role of ice flow in shaping supraglacial debris patterns at glacier scale. The reconstructed debris input patterns allow us to reproduce the observed historical evolution of debris extent and glacier geometry with good agreement. Debris extent matching between simulations and observations reaches around 80%, while the percentage of the total particles ending up in the target debris area remains above 70%. Ongoing work addresses the reconstruction of debris thickness, which is sensitive to both the debris weight (i.e. the assigned debris volume) prescribed for each particle and, crucially, the climatic forcing, requiring an iterative approach to capture the full transient characteristics of the glacier debris cover.
This study demonstrates that ensemble-based Lagrangian modelling provides a powerful framework to constrain debris input to glaciers. By explicitly coupling debris transport to the evolving glacier dynamics, this approach opens new perspectives for interpreting present-day debris cover and for projecting the future evolution of debris-covered glaciers under changing climatic conditions.
How to cite: Muñoz-Hermosilla, J. M., Miles, E., McCarthy, M., Melo Velasco, V., Hardmeier, F., Gantayat, P., Fontrodona-Bach, A., Jouvet, G., and Pellicciotti, F.: Constraining debris input to Oberaletsch Glacier using ensemble-based Lagrangian modelling, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19367, https://doi.org/10.5194/egusphere-egu26-19367, 2026.
Glacier complexes in the Manaslu region of Nepal Himalaya have been experiencing only moderate mean area losses and geodetic mass balance since the 1970s (~ -0.26 % a-1, -0.17 ± 0.03 m w.e.a−1. Many debris-covered glacier tongues exhibit large amounts of supra-glacial vegetation and stagnating patterns. Here, we investigate these apparent patterns of stagnation of glacier systems in this area, specifically the prevalent vegetation development and the geomorphological characteristics of debris cover tongues. We use remote sensing-derived surface velocities derived from image cross-correlation (RGDyn open-source package) based on Landsat and Sentinel-2 time series combined with high-resolution declassified Corona imagery and Pléiades. Preliminary results indicate ~8 % supra-glacial vegetation coverage at a regional scale and general glacier slowdown with variable movement rates depending on glacier morphology and debris covered characteristics.
How to cite: Racoviteanu, A. E., Fichant, A., Cusicanqui, D., Glasser, N., Millan, R., Harrison, S., and Robson, B. A.: Vegetated debris-covered glaciers and stagnating patterns in the Manaslu region of Nepal Himalaya, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14771, https://doi.org/10.5194/egusphere-egu26-14771, 2026.
Over the past century, more than two dozen tsunamis with runups greater than 50 m have been reported. Of these, more than half were in the Arctic or subarctic, including the 1958 Lituya Bay megatsunami, which ran up 530 m in elevation. Many of those megatsunamis occurred in deglaciating fjords or valleys, and almost all were triggered by landslides. At 5:26 a.m. local time on 10 August 2025, a large landslide (>64x106 m3) collapsed about one vertical km onto South Sawyer Glacier and into Tracy Arm, a cruise ship-frequented fjord in southeast Alaska. The landslide triggered a megatsunami, which reached an elevation of 481 m up the opposite fjord wall before propagating out of the fjord into Stephens Passage and Endicott Arm to the south. The tsunami was experienced by multiple ships in the vicinity, but due in part to its early morning timing, luckily no deaths or injuries occurred.
The initial rock wedge failure transitioned into a rock avalanche as it traveled down the slope and produced globally observed long-period seismic waves equivalent in size to those of a M5.4 earthquake. The landslide was also preceded by more than 24 hours of microearthquakes attributed to slip along the failure surface, with increasing rate and amplitude until roughly an hour before failure. Long-period monochromatic global seismic signals persisted for over 36 hours. These signals are consistent with a landslide-induced seiche trapped in the fjord, an interpretation further confirmed by tsunami simulations and satellite observations.
The landslide and resulting hazard cascade was enabled by >6 km of retreat of South Sawyer Glacier since 1948, which we statistically attribute to anthropogenic warming. Most recently, the base of the failed slope was fully exposed between late June and early August 2025 when the glacier retreated several hundred metres. A large failure of a slope that had not previously been identified as a hazard, and with no precursory slope deformation, in a fjord with extensive recreational activity (e.g., cruise ships and personal pleasure craft) highlights the near-field risk of landslide tsunamis and underscores the importance of enhanced monitoring and continued research using a variety of tools, including seismic, remote sensing, and in situ monitoring.
How to cite: Shugar, D., Barnhart, K., Berdahl, M., Caplan-Auerbach, J., Ekström, G., Fathian, A., Geertsema, M., Hicks, S., Higman, B., Jensen, E., Karasözen, E., Lynett, P., Lyons, J., Monahan, T., Roe, G., Svennevig, K., Toney, L., Van Wyk de Vries, M., and West, M.: The second highest tsunami ever recorded, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3156, https://doi.org/10.5194/egusphere-egu26-3156, 2026.
The melting rate of glaciers in Europe has accelerated continuously since the 1980s and continues today at an unprecedented pace. Such rapid and sustained glacier retreat has important implications for the release of legacy contaminants stored in ice. Since the onset of the Industrial Revolution, atmospheric deposition has led to the accumulation of pollutants, including mercury (Hg)—a highly toxic element with well-documented impacts on ecosystems and human health—within glaciers. Ongoing climate-driven melting can remobilize these long-term contaminant reservoirs.
To investigate this process, we examined Hg accumulation rates (Hg AR) in sediments from two neighboring high-altitude lakes in the French Alps. One lake represents a reference system receiving only atmospheric inputs, while the other is influenced by both atmospheric deposition and meltwater from a shrinking glacier. Comparing the two sedimentary records allowed us to isolate the signal associated with cryospheric change.
In the reference lake, Hg AR is controlled by regional atmospheric Hg emissions and follows the expected anthropogenic pattern, with maxima during World War II and in the 1970s, followed by a steady decline in recent decades. In contrast, the glacier-fed lake shows a steadily increasing Hg AR from the early 1900s to the present, with a doubling of accumulation rates over the past several decades.
Using estimates of glacier volume loss over the last 50 years together with Hg concentrations in glacier ice and cryoconite reported in the literature, we demonstrate that the recent acceleration of Hg AR is consistent with enhanced Hg release driven by glacier shrinkage. These results indicate that glacier melt represents an additional and climate-sensitive source of legacy Hg to downstream aquatic systems, compounding the environmental impacts of cryospheric change alongside pressures such as freshwater scarcity.
How to cite: Mattio, D., Guedron, S., Sabatier, P., Dommergue, A., Martínez Cortizas, A., Rabatel, A., and Angot, H. and the EPOCH ALPS team: The Hidden Threat of Glacier Melt: Rising Mercury Levels in French Alpine Lakes, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1802, https://doi.org/10.5194/egusphere-egu26-1802, 2026.
The Qilian Mountains (QM), the source of three inland rivers in the Hexi Corridor, Northwest China, play a crucial role in regulating water resources. However, there is currently a lack of systematic evaluation of precipitation products, and the contribution of glaciers to basin runoff remains uncertain. This study assesses multiple high-resolution precipitation products in the QM and identifies the most accurate dataset (CHM_PRE). It also analyzes the spatiotemporal distribution of precipitation in glacier and non-glacier areas of the upper reaches of the Shiyang (URSYH), Heihe (URHH), Beida (URBDH), Shule (URSLH), and Danghe (URDH) river basins. The results show that annual precipitation in glacier areas of the five basins is significantly higher than in non-glacier areas. However, since glacier areas occupy only a small fraction of each basin (0.32-4.37%), the contribution of precipitation in glacier areas to total basin precipitation is correspondingly limited (0.34-5.31%). Previous studies estimated that glaciers contribute 4.1-6.1%, 2.7-3.5%, 12.1-23.1%, 23.3-51.2%, and 46.8-47.8% of annual runoff in the URSYH, URHH, URBDH, URSLH, and URDH basins, respectively, whereas our results indicate that their contributions do not exceed 2.4%, 1.2%, 9.1%, 19.8%, and 15.3%, respectively. Overall, previous studies have substantially overestimated glacier meltwater contributions to runoff in the five basins on the northern slope of the QM, with overestimation rates ranging from 18% to 212%. Accurate assessment of glacier roles is essential for the scientific management of water resources in the region.
How to cite: Yang, M. and Li, Y.: Are glaciers actually critical for basin runoff in the northern Qilian Mountains, Northwest China?, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4394, https://doi.org/10.5194/egusphere-egu26-4394, 2026.
The cryosphere is experiencing rapid decline due to climate change, with 25-54% mass loss of the world’s glaciers predicted over the next century. These changes have far-reaching implications including impacts on local geohazards, regional freshwater availability, global sea-level rise, and downstream nutrient supply. Though many studies have examined the physical processes associated with glacier change, we still lack a complete understanding of the associated geochemical consequences. This is especially important to constrain as glaciated catchments are important sources of lithogenic nutrients due to mechanical and chemical weathering, and meltwater transport in turn influencing downstream ecosystems.
To better constrain the effects of subglacial weathering on glacial runoff chemistry, water and ice samples were collected at Storglaciären and Isfallsglaciären, two polythermal glaciers in the Tarfala Valley, Arctic Sweden in the summers of 2024 and 2025. These glaciers have experienced dramatic thinning and retreat for the past century, with this trend recently accelerating. Water temperature, conductivity, pH and other parameters were measured in situ. Samples were analyzed for major and trace ion concentrations, total carbon, and stable water isotopes. These are the first reported geochemical measurements of this kind for the reference glacier Storglaciären.
Aqueous geochemistry results indicate that chemical weathering of the bedrock is likely driven by a combination of both carbonic (H2CO3) and sulfuric (H2SO4) acid dissolution, resulting in major cations (e.g., Ca, Mg), Si, and Fe being released from subglacial sediment. Solute concentrations are highest at the cold-based ice margins, indicating increased dissolution of Fe- and Mg-rich bedrock in these areas. Concentrations of sulfate are also highest under the cold ice, most likely due to increased FeS2 oxidation at the cold-based margins of the glacier.
These results indicate that heterogeneous oxidation most likely drives acidic weathering in the subglacial environment, and that this process appears to be more effective in the more stable, cold-based margins of the glacier where residence times of sediment are longer. Localized silica precipitation is more prevalent in the warm-based portions dominated by subglacial meltwater, glacial sliding, and seasonal flushing of sediment and water. These results suggest that there may be detectable differences in alteration processes between cold- and warm-based glacial thermal portions of ice sheets and glaciers, that these differences are detectable in local meltwaters, and that significant amounts of solutes are generated by subglacial alteration processes and transported to lower elevation Arctic ecosystems. It is imperative that future studies include repeat meltwater monitoring at these rapidly changing systems to understand the ongoing effects of climate change on glacial water chemistry and downstream nutrient supply.
How to cite: Rutledge, A., Havig, J., Horgan, B., Salvatore, M., De Anda, C., and Marrs, I.: Meltwater chemistry at two rapidly retreating Arctic Sweden glaciers: Implications for downstream nutrient supply in a warming climate, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-15904, https://doi.org/10.5194/egusphere-egu26-15904, 2026.
The Arctic is experiencing rapid climatic warming. The inflow of warm Atlantic Water through the Fram Strait is an additional forcing to the stability of the Arctic cryospheric system, with the Svalbard archipelago being especially sensitive to its primary influence. While recent studies show the “greening” of this region through remote sensing and field observations, this study investigates modern palynological assemblages from fjord surface sediments at 34 different locations in Spitsbergen and Nordaustlandet to explore where this phenomenon is prevalent at an ecosystem scale. Long-distance transported pollen such as Pinus and Betula are consistently identified across fjords, while various and local pollen compositions are observed more in Isfjorden where intensive human activity and substantial retreat of tidewater glaciers have been reported. In addition to herbaceous pollen taxa, shrub pollen including Salix and Dryas is present on the western side of the archipelago more often. During pollen identification, abundant testate amoebae were also detected at most locations. We propose the following explanation on the observed palynological assemblages. Overall, pollen records from the surface fjord sediments reflect terrestrial environmental conditions effectively and spatially. The exposure of newly deglaciated surfaces where soils develop, subsequent ecological succession on these soils facilitates Arctic shrubification. Soil development can be inferred from testate amoebae, and Arctic greening can be detected through local pollen spectra. In our future analysis, the onset of these modern palynological assemblages can be identified through the investigation of fjord long core sediments.
How to cite: Lee, M., Kim, S.-Y., Kim, J.-H., and Byun, E.: Modern palynological assemblages in fjord surface sediments: indicators of Greening Svalbard, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7722, https://doi.org/10.5194/egusphere-egu26-7722, 2026.
In High Mountain Asia (HMA), glaciers and seasonal snowpacks have seen a widespread decline in the last two decades. However, these changes have been highly heterogeneous: glaciers of the Pamirs and Karakoram have seen positive mass balances in the early 2000s but are now on a trajectory of decline, while moderate and rapid mass loss occurs in the Central Himalayas and southeastern Tibetan Plateau, respectively. To understand these contrasting behaviours, their future trajectory, and their impacts on streamflow, we combine several years of situ observations and climate reanalysis with highly resolved land-surface and ice-flow models. We simulate water fluxes from 1970 to 2100 across three catchments with contrasting climatic settings. The catchments are in the Northwestern Pamirs (Kyzylsu), Central Himalayas (Trambau-Trakarding), and Southeastern Tibetan Plateau (Parlung No.4), spanning elevations from 2100 to 6800 m a.s.l..
We simulate the largest mass loss acceleration at Parlung No.4 Glacier, from -0.10 m w.e. yr-1 in 1970-1999 to -0.80 m w.e. yr-1 in 2000-2023. The limited mass loss at Kyzylsu in 1970-1999 accelerated after 2000, mostly driven by a rapid worsening of glacier health in 2018-2024 (-0.72 m w.e. yr-1). Mass loss remained moderate at Trambau-Trakarding, from -0.39 m w.e. yr-1 in 1970-1999 to -0.30 m w.e. yr-1 in 2000-2023.
These heterogeneous glacier mass balance patterns were driven by different summer 0°C isotherm changes, and contrasting precipitation decadal variability. Our projections forced with downscaled CMIP6 show that continued warming will expand ablation areas and extend melting into former accumulation areas previously located above the freezing line. On-glacier summer snowfall is projected to decrease by up to 60% by 2100 due to changes in precipitation phase. However, this will largely be offset by increases in snowfall in other seasons, driven by the widespread rise in precipitation projected for HMA. Despite stable accumulation rates, enhanced melt will drive severe glacier volume loss, strongly reducing the likelihood of new prolonged periods of near-stable or positive mass balances seen in our 1970-2020 simulations.
Glacier retreat, combined with snowline rising to 6000 m a.s.l., will shift meltwater generation to higher elevations, where mass turnover rates will intensify. High-elevation areas will maintain their role as water providers, but with diminished capacity for water storage. We find that the evolving runoff contributions can decouple catchment-scale peak water from glacier-scale peak water. Indeed, substantial increases in rainfall (from 49 ± 22 % at the catchment in the Pamirs to 290 ± 146 % in the southeastern Tibetan Plateau), caused by precipitation phase and amount changes, and relatively stable snowmelt compensate for ice-melt reduction and postpone the timing of maximum runoff. While we find that ice melt nears its peak at Kyzylsu, with considerable uncertainty due to the initial ice volume, we project catchment runoff to continue increasing at all sites until the end of the century. Our results highlight the importance of considering the glacier 'peak water' concept within a catchment or basin hydrological framework.
How to cite: Jouberton, A., Shaw, T., Miles, E., Kneib, M., Fujita, K., and Pellicciotti, F.: Past and future drivers of glacier mass changes in High Mountain Asia and their impacts on catchment hydrology, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10641, https://doi.org/10.5194/egusphere-egu26-10641, 2026.
In recent decades, an increased frequency of heat waves (HWs) has been detected along the subtropical Andes (SA); however, their impact on the cryosphere has not been assessed in detail. Here we present a multi-scale assessment with the objective of quantifying the impact of HWs on Andean glaciers located in the SA. Sub-daily observations of melt at the Universidad (34°S) and Pichillancahue (39°S) glaciers show that the daily melt rate increases by approximately 25% during HW events compared to the rest of the ablation season. At the annual scale, the relationship is complex. Using seasonal HWs climatologies derived from the ERA5 reanalysis and glacial mass balances available from the World Glacier Monitoring Service (WGMS), it was determined that there is no significant relationship between the number of HW events and the annual mass balance. However, the annual mass balance of the Echaurren Norte Glacier (33°S) showed significant positive correlations (p<0.05) with the number of HW events occurring over the Pacific Ocean, during the spring and summer seasons between 1975 and 2023. Furthermore, the mass balance of the Piloto Este Glacier (33°S) also shows significant positive correlations with the number of HW events in the Pacific during spring and summer between 1979 and 2002. These correlations would indicate the importance of the higher evaporation rate during HW events, with the consequent contribution of moisture to the atmosphere, contributing to precipitation and snow accumulation on glaciers during synoptic events occurring over the Andes. The above is consistent with the fact that glaciers in the central Andes of Chile and Argentina are more sensitive to precipitation variability, as well as its relationship with the El Niño-Southern Oscillation (ENSO). While melt rates increase during HW events, the forcing of evaporation rates during HW events over the Pacific would generate a greater impact on the annual glacier mass balance. This finding, from a glaciological perspective, calls for further investigation into the role of HW events over the oceans as drivers of evaporation and their transport and circulation mechanisms. This work is funded by the FONDECYT Iniciación Project 11240379.
How to cite: Bravo, C., Gonzalez-Reyes, A., Bozkurt, D., and Cisternas, S.: Heat wave events and the response of glaciers in the subtropical Andes, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-15852, https://doi.org/10.5194/egusphere-egu26-15852, 2026.
Glaciers are sensitive indicators of climate change, yet only a small number that remain in the Mediterranean region. Of these, most have retreated well into cirques, persisting as small, isolated glaciers or ice patches. The climatic drivers of glacier and snowpack changes across the Mediterranean mountains over the past 75 years are assessed using temperature, precipitation, snow cover, and glacier mass balance data. Summer temperatures in the Mediterranean region have risen dramatically since the 1970s with the average increasing by >1.9 °C by 2024 relative to the 1991–2020 mean. Winter precipitation in the Mediterranean region has shown a slight decline over the last 75 years. From 2019 to 2023, snow cover duration declined across most of the Mediterranean. Regression analysis indicates that the North Atlantic Oscillation (NAO) exerts only a limited influence on glacier mass balance and snowpack variability in the Mediterranean. This is because the dominant control on mass balance change in the Mediterranean is summer temperature rather than precipitation, much more so than further north in Europe where NAO has more influence on glaciers. Despite this strong temperature sensitivity, some Mediterranean glaciers persist due to favourable local topoclimatic conditions. In particular, enhanced snow accumulation from snow avalanching and windblown snow compensates high summer ablation, highlighting the key influence of local topoclimatic conditions on glacier survival in the Mediterranean region. Although Mediterranean glaciers are sustained by high accumulation, they are strongly affected by summer temperature variability, reflecting the broader global pattern whereby warm–wet glaciers show greater temperature sensitivity than cold–dry glaciers. Understanding how glaciers and snowpack respond to climate change in the Mediterranean mountains has relevance beyond this region and provides an important comparison for other mid-latitude regions, such as the Alps, the Caucasus, and the Tibetan Plateau, where glaciers and snowpack are crucial for water supply.
How to cite: Wang, B., Hughes, P., Darvill, C., and Woodward, J.: The impact of climate change on mid-latitude Mediterranean glaciers over the past 75 years, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1956, https://doi.org/10.5194/egusphere-egu26-1956, 2026.
Understanding how ice caps and glaciers respond to climate change is essential for improving projections of present and future sea-level rise. The Holocene provides a valuable time period for this purpose, as it encompasses long-term ice–climate interactions and a transition from colder to warmer conditions comparable to today.
Here we investigate the Holocene glacial history of the region presently covered by the Flade Isblink ice cap in northeast Greenland, a remote and high-elevation ice mass that is not directly connected to the Greenland Ice Sheet and is therefore particularly sensitive to climate forcing.
Flade Isblink is situated on the Kronprins Christian Land plateau and drains through fast-flowing outlet glaciers into the Arctic Ocean, storing a substantial volume of freshwater. Its geographic setting makes it an excellent indicator of Arctic climate variability. Here, we focus on identifying which parts of the ice cap survived the Holocene Thermal Maximum and on reconstructing ice extent in regions where geological constraints are sparse.
We use a two-dimensional coupled ice-flow and surface mass balance model implemented in the Ice Sheet and Sea-level System Model (ISSM) to simulate ice evolution from 12.4 ka BP to the present. Time-varying bedrock uplift and relative sea-level change are incorporated through an offline glacial isostatic adjustment (GIA) solution. To account for uncertainties in climate forcing, we run an ensemble of simulations spanning a range of climate scenarios. Model results are evaluated against geomorphological evidence, dated materials, and present-day ice geometry.
How to cite: Bråtner, A., Morlighem, M., Seroussi, H., and Khan, S. A.: Modelling the Holocene evolution of Flade Isblink, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-15329, https://doi.org/10.5194/egusphere-egu26-15329, 2026.
Glacier mass loss has accelerated globally in recent decades, yet many regional and global glacier models still rely on temperature-index melt formulations that limit physical realism and process attribution. Physics-based approaches, such as surface energy balance (SEB) models, can overcome these limitations but are challenging to apply at regional scales because they require climate forcing resolved at local scales. Global climate models and reanalysis products are known to perform poorly in complex mountainous terrain without downscaling and bias correction. In addition, albedo parameterizations in SEB models typically require calibration against in-situ observations, which are sparse for most glacierized regions.
Here, we evaluate the skill of a physics-based glacier modeling framework designed to reconstruct glacier mass changes with minimal parameter calibration and without downscaling, and with only limited bias correction of climate input data. We first assess a relatively simple SEB model forced by climate variables from the European Centre for Medium-Range Weather Forecasts ERA5 reanalysis. Surface albedo, a key input to the SEB model, is prescribed using a standalone machine-learning model trained on Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations. We show that calibration of selected model parameters—most notably precipitation correction and albedo bias correction—is required for the model to perform well from local to regional scales across western Canada. We then evaluate a more complex SEB formulation using the open-source COupled Snowpack and Ice surface energy and mass balance model in PYthon (COSIPY), with the aim of assessing whether parameter calibration can be further reduced or avoided. We find that neural-network-based albedo estimates substantially improve model performance and that calibration-dependent albedo bias correction is no longer required when Landsat data are used instead of MODIS. In contrast, wind speeds from ERA5 require bias correction to obtain realistic turbulent heat fluxes, highlighting the importance of improving the representation of katabatic winds over glacier surfaces. With these adjustments, the non-calibrated physics-based model performs well in simulating summer mass balance at the glacier scale, provided that snow accumulation at the onset of the melt season is adequately captured.
How to cite: Radic, V., Phelps, H., and Draeger, C.: Toward Minimally Calibrated Physics-Based Glacier Mass Balance Modeling, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-15272, https://doi.org/10.5194/egusphere-egu26-15272, 2026.
Glacier subsurface melt, consisting of englacial and basal melt, is far less understood than surface mass balance. Yet it represents a potentially relevant component of glacier retreat dynamics. Research on subsurface melt has been limited due to scarce observations and incomplete process understanding.
Here, we quantify spatially distributed subsurface melt of Swiss glaciers using a modelling approach, constrained and validated by field observations. To constrain the model, we use field data on energy content of subglacial water and airflow collected at 5 individual glaciers. This included water temperature and discharge measurements of ice-marginal, subglacial, supraglacial and proglacial streams, as well as measurements of melt and air flow inside ice caves. To acquire validation data on subsurface melt rates, vertical ice motion of ablation stakes was measured on the glacier terminus of two glaciers using differential GPS. After correcting for advection and ice flow divergence, residual vertical ice motion was assumed to be equivalent to subsurface melt. The parameterized subsurface melt model is based on sub- and englacial energy exchanges and uses surface mass balance, glacier geometry, catchment topography, and weather data as primary inputs. Subsurface melt is represented through several components: (1) geothermal heat flux, (2) frictional and strain heating, (3) potential energy release from meltwater, (4) advection of energy from ice-marginal and supraglacial streams, and (5) airflow through subglacial channels. To model the spatial distribution of subsurface melt we use spatially distributed surface mass balance, flow routing, and assumptions on energy exchange between subglacial water and ice.
Model results indicate that the dominant contribution to subsurface melt comes from energy input by ice-marginal streams, followed by potential energy release of meltwater. Glacier-wide annual subsurface melt rates averaged across Swiss glaciers are in the order of tens of mm w.e. a-1, with larger glaciers generally exhibiting higher subsurface melt rates. Spatially, subsurface melt is highest near glacier termini, reflecting the location of ice-marginal stream inflow. A high elevation gradient (potential energy release) and a larger glacier area (larger catchment for ice-marginal streams) were identified as key controls on elevated subsurface melt rates. Validation data were found to be of the same order of magnitude as modelled values at the two respective field sites.
These results demonstrate that subsurface melt can be quantified using a combination of direct field observations and spatially distributed modelling. By providing spatially resolved estimates of subsurface melt for Swiss glaciers, this approach allows subsurface processes to be better understood and explicitly included in glacier evolution models. This constitutes an important step towards a more comprehensive and physically consistent description of glacier mass balance under ongoing climate change.
How to cite: Hösli, L., Huss, M., and Farinotti, D.: Modelling subsurface melt of Swiss glaciers, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11322, https://doi.org/10.5194/egusphere-egu26-11322, 2026.
Glaciers in Patagonia and Tierra del Fuego remain among the least studied worldwide, despite experiencing pronounced mass loss over recent decades. Many glaciers in this region terminate in lakes or the ocean, making their evolution dependent on mass balance both directly controlled by climatic forcing at the glacier surface as well as dynamically controlled at the ice front. Recent studies demonstrate that warming air temperatures have increased surface melt rates significantly, suggesting climatic changes as the main driver for the observed losses. Climatically driven thinning can, however, trigger ice-dynamic instabilities, potentially amplifying glacier retreat.
To improve our understanding of the interaction of both components, climatic mass balance and glacier dynamics, we aim to establish a comprehensive modelling framework for Schiaparelli Glacier in Tierra del Fuego. Schiaparelli Glacier terminates in a proglacial lake that formed after recession in the 1940s. Ice thickness reconstructions reveal a potential overdeepening near the glacier front, which may lead to a self-accelerating ice-dynamic retreat once the glacier retreats into deeper water. This setting, combined with the availability of more than a decade of glaciological, meteorological and hydrological in-situ observations, makes Schiaparelli Glacier an attractive and exciting research target.
The aim of this study is to set up a modelling framework to simulate the evolution of Schiaparelli Glacier in the past and future, covering the Little Ice Age to the end of the 21st century. To do so, we will rely on the FROST framework (“Framework for assimilating Remote-sensing Observations for Surface mass balance Tuning”), which applies an Ensemble Kalman Filter to calibrate glacier-specific surface mass balance parameters using remote sensing observations. FROST is coupled to the Instructed Glacier Model (IGM) to capture the glacier dynamics. We further upgrade the surface mass balance scheme from a basic temperature-index model to a simplified energy balance model that explicitly accounts for solar radiation. Past glacier extents derived from moraine and tree-ring dating are used to validate the reconstructed glacier evolution of Schiaparelli Glacier.
How to cite: Temme, F., Berkhoff, J., Herrmann, O., Langhamer, L., Tabone, I., Jaña, R., and Fürst, J.: From the Little Ice Age to the future: modelling the evolution of Schiaparelli Glacier, Tierra del Fuego, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17201, https://doi.org/10.5194/egusphere-egu26-17201, 2026.
In High Mountain Asia (HMA), glacier meltwater plays a critical role in regulating seasonal river discharge and supporting water availability for populations living in mountainous and downstream regions. Observed acceleration in glacier mass loss over recent decades, together with projected future warming and changes in precipitation, is expected to modify the timing and magnitude of meltwater contributions, with significant implications for regional water security, sustainable development, and glacier-related hazards. To quantify glacier responses to climate change under different emission scenarios, we model glacier evolution across diverse climatic settings in HMA, including the Central Karakoram, Tibetan Plateau, and Central Himalaya. We use a MOno-Layer Higher-Order ice-flow model within the Ice-sheet and Sea-level System Model on an unstructured triangular finite-element mesh, locally refined at high spatial resolution (30–500 m) based on present-day observed surface velocities. We use a nonlinear Budd friction law and the basal friction coefficients are inferred using surface velocity observations from 2022. Surface mass balance (SMB) is computed using a temperature-index method that explicitly accounts for debris cover effects. The SMB model is calibrated against geodetic mass-balance estimates derived from stereo imagery (2000–2020) and validated using satellite altimetry observations (2003–2023). We simulate the glacier evolution from 2000 to 2100 under SSP1-2.5, SSP2-4.5, SSP3-7.0, and SSP5-8.5 using climate forcing from five global climate models (GCMs). Based on ensemble of all five GCMs, glaciers are projected to loose 10 ± 16% (SSP1-2.5) to 98 ± 2% (SSP5-8.5) of their mass by 2100, relative to 2000 across the regions. Among all studied region Monumaha Ice field and Purogangri Ice Cap on Tibetan Plateau exhibit a maximum mass loss of up to 70 ± 22 to 98 ± 2%. We find that on individual glaciers mass change debris cover play an important role, particularly in Central Karakoram region where debris cover delayed the mass loss by 15% by the end of 2100. One of the major takeaways for our study is that compared to earlier studies based on flowline models, our estimates show that glacier mass change differs significantly
How to cite: Hassan, M., Kayastha, R. B., Cheng, G., Chand, M. B., and Hassan, J.: Modeling Glacier Evolution Across Different Climatic Regions of High Mountain Asia, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21674, https://doi.org/10.5194/egusphere-egu26-21674, 2026.
The heterogeneous ablation rates of debris-covered glaciers strongly influence mass balance and melt patterns, yet the factors controlling this variability remain poorly understood. To understand this, this study quantifies ablation dynamics across the debris-covered zone of Panchinala A glacier, located in western Himalaya, India, using high-resolution unmanned aerial vehicle (UAV) photogrammetry data. Multi-temporal UAV surveys were conducted during ablation seasons of 2021 and 2022 to generate orthomosaics and digital elevation models (DEMs) at centimeter-scale resolution. Surface velocity was estimated using the More Global Matching algorithm implemented in the Ames Stereo Pipeline and combined with independent ice thickness estimates to compute flux divergence. Flow-corrected Lagrangian surface mass balance (SMB) was estimated using a continuity-equation approach, applying mass conservation under an assumption of constant ice density. During 2021–2022, the ablation area exhibited a mean horizontal velocity of 4.40 m a⁻¹; velocities decreased progressively along-flow toward the glacier front. The mean Lagrangian SMB across the ablation area was -602.6 kg m-² a-1 (2021–2022). The result indicates contrasting ablation patterns over ice cliffs and debris covered area. Ice cliffs and adjacent ablation hotspots (10 m buffer) contributed ~50% of total ablation while occupying ≤20% of the ablation area, whereas the remaining debris-covered surface (~80%) accounted for ~50%. These results show that high-resolution datasets are important for accurate surface mass balance estimation and for resolving the spatial heterogeneity of ablation on debris-covered glaciers.
How to cite: Godara, A. and Ramsankaran, R.: Quantifying Ablation Dynamics in the Debris-Covered Zone of Panchinala-A Glacier Using High-Resolution UAV Photogrammetry, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3421, https://doi.org/10.5194/egusphere-egu26-3421, 2026.
Accurate estimation of current and historical glacier area provides crucial information for glacier monitoring and for projecting future glacier change. Despite significant advances in remote sensing, automated glacier delineation techniques still exhibit limited accuracy in debris-covered areas, often requiring time-consuming manual corrections, which are impractical for widespread application. While some regions have rich historical records of glacial development due to ease of access and scientific prioritization, many regions are represented by only a few outlines.
The Himalayas contain many large and heavily debris-covered glaciers, whose retreat and increase in debris coverage could drastically affect the primary source of freshwater for many communities. This vast and important region, however, has very few harmonized and temporally consistent datasets available for scientific use. Existing inventories are generally derived from imagery acquired in different years and exhibit substantial differences in their debris-covered area outlines.
Thus, to improve on these inconsistencies and inaccuracies, we are creating a historical time series spanning the entirety of the Himalayas between 1984 and 2025 with two-year intervals. To overcome the difficulties inherent to debris-covered glacier inclusion, several data sources are used, including optical, infrared, thermal, spectral indices, elevation change rate, surface velocity, and topographic parameters. These data sources are trained on a deep learning network comprised of a pre-trained U-Net with a long short-term memory (LSTM) module, which enhances debris segmentation by introducing historical data to the training process. In addition, the potential benefit of including radar coherence data is evaluated to assess whether glacier outlines produced in recent decades can be further refined.
How to cite: Lutz, K., Wolf, A., and Braun, M.: A historical time series of glacial debris cover change in the Himalayas using multi-source satellite data and deep learning, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6503, https://doi.org/10.5194/egusphere-egu26-6503, 2026.
Debris-covered glaciers influence the regional hydrological cycle by modulating glacier melt processes. One important control on melt variability on debris-covered glaciers are ice cliffs, which have been identified as melt hotspots, exhibiting ablation rates that far exceed those of the surrounding debris-covered area. As a result, they contribute disproportionately to total glacier mass loss. However, their dynamics and contribution to overall ablation have been quantified for only a few glaciers, mainly in the Himalaya. Quantifying and parameterizing ice cliff dynamics, including modelling frameworks, is needed to reliably project the future evolution of debris-covered glaciers in different mountain regions, as well as their water supply.
The aim of this study is to quantify ice cliff melt and backwasting rates in alpine settings, to generate a reference dataset for ice cliff model applications and to assess their relative contribution to total ablation. Ablation and dynamics of four ice cliffs were measured between 26 August and 19 September 2025 at the Kanderfirn. The Kanderfirn, a valley glacier in the Swiss Alps, was selected for this study as the tongue comprises both debris-covered and debris-free areas and, thus, enables the study of different ablation processes at the same site. Four ice cliffs representing the four cardinal orientations were selected to assess differences in melt and backwasting rates related to the ice cliff orientation, which are discussed in the literature. In total, eight stakes were installed at the four ice cliffs, with one stake drilled into the bare ice face of each cliff and a corresponding stake placed in the debris-covered area immediately above each cliff, to quantify the vertical, tangential and sub-debris melt rates as well as horizontal backwasting rates. Eleven additional stakes were installed at sites with varying debris thickness. Moreover, repeated UAV surveys were carried out to generate digital elevation models for the investigation of the geometric evolution of the ice cliffs over a one-month period. Finally, a surface energy-balance model was applied to model ice cliff and sub-debris ablation using the UAV-based digital elevation model and meteorological data from on- and off-glacier weather stations.
The in-situ results show clear contrasts in melt rates between ice cliff faces and the surrounding debris-covered area, as well as variability among ice cliffs with different orientations, including differences in backwasting rates. Two separate estimates of apparent vertical melt rate are derived from tangential melt measurements as well as from backwasting and sub-debris melt, combined with the slope angle. The close agreement between both results indicates consistent field measurements. The measurements and modelling provide valuable insights into the ablation and dynamics of ice cliffs on an Alpine glacier.
How to cite: Kogel, A. C., Zöller, A., Mayer, C., and Groos, A. R.: Ablation and dynamics of four ice cliffs on the partially debris-covered glacier tongue of Kanderfirn, Swiss Alps, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18086, https://doi.org/10.5194/egusphere-egu26-18086, 2026.
The Pyrenees range is the most southern European region with active glaciers and rock glaciers. In the current climate change context, their depth, extent and viability are rapidly declining. Even though they are usually located in high-elevation and remote areas, their dynamics can affect human settlements and activities. Mapping and monitoring these ice bodies will provide more information about their past, present and future evolution.
Remote sensing data provides extensive information, especially in rough mountainous areas and inaccessible or distant regions. Differential and Multitemporal interferometry (DInSAR and MT-InSAR) has been extensively proven to be a valuable tool to detect ground deformations, but also works to provide insightful results over glacial and periglacial environments. Since many authors have found SAR data useful in this context, there is a scarcity of works that exploit the high spatial and temporal resolution of X-band dense constellations such as COSMO-SkyMed. On the other hand, this kind of ice bodies are usually located over low satellite-visibility areas (related to shadow and layover effects), increasing the importance of alternative information, such as that provided by in-situ (GNSS) or near-remote sensing (UAV).
This work compares coverture and displacement results from Sentinel-1 C-band (both DInSAR and MT-InSAR) and COSMO-SkyMed X-band data. MT-InSAR results from EGMS revealed low coverage due to geometrical and snow-cover issues, while DInSAR results from both constellations provide better coverage results. UAV flights over the glacier allowed perfect coverage and high spatial resolution, but lacked in temporal resolution. Lastly, a GNSS measurement grid was redeployed over the glacier and will provide displacement data for future campaigns and for comparison with previous campaigns in the 90s. Combining data from UAV flights, three-dimensional displacement is estimated and compared with InSAR results, after projection in the Line of Sight (LOS), with the InSAR displacements. This work is part of JDC2023-052719-I, financed by MCIU/AEI/10.13039/501100011033 y and FSE+.
How to cite: Ezquerro, P., Revuelto, J., López-Vinielles, J., Izagirre, E., Domínguez Aguilar, P., Bandrés, J., Rojas Heredia, F., Monserrat, O., and López Moreno, J. I.: Monitoring Argualas rock glacier dynamics combining InSAR, GNSS and UAV data, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-22830, https://doi.org/10.5194/egusphere-egu26-22830, 2026.
Debris on glacier surfaces has a strong effect on glacier melt and is currently expanding and thickening due to climate change. Several studies have applied coupled debris-ice dynamic modelling in order to simulate the evolution of debris-covered glaciers. However, many aspects within these dynamic systems remain poorly constrained, as data is scarce and processes are complex and interdependent. So far, most approaches focused on the simulation of the debris layer in the ablation area, but preceding processes of debris supply through gravitational processes and englacial debris transport are often represented based on simple assumptions or limited measurements and with unknown uncertainties. In this study, we address this issue by investigating how changes in the spatial distribution of debris supply affect down-glacier debris transport and debris cover.
For this, we apply a novel 3-dimensional coupled debris-ice dynamics model, implemented within the Instructed Glacier Model (IGM), that uses particle tracking to model englacial and supraglacial debris transport. In this approach, particles need to be seeded to initialize their entry into the glacier system. This involves the development of a framework to decide where and at what rate we seed these particles. We test several approaches and implement a scheme that automatically generates seeding locations based on local topography. In our experiments, we find that small differences in along-flow seeding location can have a strong impact on englacial transport paths, debris cover extent, and finally glacier extent. This reasserts the need to better constrain debris supply as an important part of the process chain if we want other aspects to be accurately represented in models.
How to cite: Hardmeier, F., Miles, E., Muñoz-Hermosilla, J. M., Jouvet, G., and Vieli, A.: The effect of debris supply on glacier evolution: sensitivities and challenges, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21688, https://doi.org/10.5194/egusphere-egu26-21688, 2026.
Debris-covered glaciers have been widely recognized in glacier runoff contributions and ice-rock disasters. It showed that debris-covered glaciers occupy about 27% glacierized region in the Central Himalayas. However, the delineation of debris-covered glaciers is still the bottleneck, which leads to high uncertainties in glacier change deteriorating our understanding of the hazard cascade from the collapse of rock and ice. Therefore, it is vital to provide the definitive margins of the debris-covered ice.
Here, we put forward a suitable method to locate the debris-covered glacier terminus of the Middle-West Rongbuk glacier based on multi-temporal surface elevation change data pairs from multi-source remote sensing data (such as DEM differencing, ICESat-2 laser altimetry, and InSAR technology). According to the DDh indicator (the difference in Dh), the debris-covered glacier terminus is determined. In addition, the glacial movement velocity generated from Sentinel-1 images was also used to verify the determined terminus outline of the debris-covered glacier. Our results showed that, from 1974 to 2025, the terminus of the debris-covered Rongbuk Glacier continuously migrated to higher elevations, rising from about 5240±20 m in the 1970s to 5290±20 m in the 2000s, then upward further to 5400±50 m after the 2010s. Over the past 48 years, the cumulative upward shift was approximately 160 m.
How to cite: Ye, Q., Ali, N., Ghimire, K., Wang, J., and Zhu, L.: Identifing the debris-covered terminus for the Middle-West Rongbuk Glacier at the Mt. Everest in the Central Himalayas, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-22641, https://doi.org/10.5194/egusphere-egu26-22641, 2026.
Cryokarst processes such as ice cliffs, ponds and collapsed subglacial cavities have been recognized to substantially enhance surface ablation on debris covered glacier surfaces. Existing flow models for debris covered glaciers, however, still largely ignore their effects, thereby limiting the related predictions and understanding of dynamic feedbacks. We propose here a process based conceptual framework that dynamically simulates the melt enhancing effect along the glacier and can be coupled to a flow-model.
We approximate the enhancing effect of cryokarst through a state variable of ice cliff area density (ICAD) and which is simulated over time and space along the glacier surface through production, advection and reduction. The production of ICAD is assumed to be driven by the processes of meltwater incision, pondsand crevassing through extensional flow; ICAD is then advected at the surface by ice-flow. Reduction in ICAD is simulated through a typical decay timescale related to debris redistribution and burial and, for crevasses, through compressional flow. The drainage of supraglacial streams to the glacier bed under tensile strain rates or through cut-and-closure allows to remove supraglacial discharge, thereby stopping ice-cliff production from supraglacial channel incision. In addition, ICAD growth from full thickness collapse of non-pressurized subglacial channel voids is parametrized through subglacial stream discharge and a threshold in ice overburden pressure. The parametrizations of the above processes are based on variables that are directly available in flow models for debris covered glaciers and encompass ice thickness, surface slope, flow speed, debris thickness and surface ablation. This framework of modelling ICAD evolution is coupled to a flowline model for debris covered glaciers that dynamically tracks debris thickness and then uses ICAD to incorporate melt enhancement relative to clean ice. The effects of including cryokarst processes and the related feedbacks are then investigated for a synthetic debris covered glacier geometry. Modelling results indicate an enhancement of glacier decay in a warming world and are compared to observed relationships of ice cliff area density to variables such as flow speed, surface slope and debris thickness.
How to cite: Vieli, A., Hardmeier, F., Miles, E., Kneib, M., and Banjeree, A.: Towards a physically based framework of cryokarst evolution for dynamic modelling of debris covered glaciers, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16695, https://doi.org/10.5194/egusphere-egu26-16695, 2026.
The Svalbard archipelago (76-81N) is undergoing increased warming compared to the global mean, which has major implications for freshwater runoff into the oceans from seasonal snow and glaciers. Quantifying changes of freshwater runoff requires close integration of observations and process-based models.
Here, we use land-surface and ice-flow modelling in combination with satellite and in-situ observations, to simulate runoff from the Bayelva catchment, Svalbard (~30 km2, ~54% glacier cover), for the period 1991–2100. Runoff from seasonal snow and glaciers is simulated using the land surface model CRYOGRID, which includes a coupled energy balance-snow/firn model. Historical simulations (1991–2024) are forced by downscaled CARRA reanalysis data and evaluated against in situ measurements and geodetic mass balance observations. Future simulations (2024–2100) are driven by temperature and precipitation trends derived from CORDEX projections under the RCP4.5 and RCP8.5 scenarios.
To account for feedbacks between surface mass balance and glacier geometry, the runoff simulations are coupled to the 3D glacier evolution model IGM. Sentinel-1 surface velocity observations are used to constrain glacier sliding, while observed surface elevation changes are used to evaluate simulated thickness changes and in situ ice-thickness measurements to evaluate the initial glacier geometry.
For continued warming, glacier melt will intensify, thus increasing runoff, but at a later stage, the reduction of glacier area due to retreat will offset this effect, giving rise to a peak in glacier runoff. The simulations indicate that runoff from the Bayelva catchment is likely to peak within the next two decades. Under the RCP8.5 scenario, both glaciers within the Bayelva catchment, Austre and Vestre Brøggerbreen, are projected to largely disappear by 2100, resulting in a transition from glacier-dominated to snow-dominated runoff.
How to cite: Schuler, T. V., Schmidt, L. S., Revheim, M. K., and Westermann, S.: Changes in glacier runoff in a warming Arctic: simulations from the Bayelva catchment, Svalbard, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16470, https://doi.org/10.5194/egusphere-egu26-16470, 2026.
Glaciers in the Indus are critical water resources, supporting agriculture, hydropower, and livelihoods for hundreds of millions of people downstream, especially during the dry season. Here, we assess changes in the future water availability from melting glaciers in the Indus basin and how this will impact future water scarcity risks. We model the evolution of all glaciers, in the Indus, larger than 0.5km2 using the Global Glacier Evolution Model (GloGEM), calibrated with transient snowline altitudes and geodetic mass balance observations. Glacier runoff projections are combined with water demand simulations from the ISIMIP3b dataset on total potential water withdrawal allowing us to explore potential future risks of water scarcity under SSP1-2.6 and SSP5-8.5 scenarios.
We analyse two different scenarios: (i) future changes in glacier runoff with present-day (2001-2020) water demand held constant, (ii) concurrent changes in both future glacier runoff and water demand. Preliminary results show that ongoing glacier mass loss in the Indus basin substantially changes the magnitude and seasonal distribution of glacier runoff. Timing of peak seasonal ablation is shifted by up to several weeks, and the overall amount of glacier runoff is reduced, which has implications for downstream water availability, particularly during the early and late summer months, when demand is highest. By disentangling the contribution of glacier runoff to water demand, this study aims to quantify the vulnerability of the Indus to future water stress and to identify conditions under which glacier retreat may exacerbate or temporarily mitigate water scarcity.
How to cite: von der Esch, A., van Tricht, L., Huss, M., van Tiel, M., Kneib, M., Berg, J., and Farinotti, D.: Modelling the Future of Indus Glacier Water Resources: Interactions between Glacier Retreat and Water Demand, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10843, https://doi.org/10.5194/egusphere-egu26-10843, 2026.
Cryosphere mainly distributes in polar and high-altitude regions, which includes glaciers, ice sheets, sea ice, lake & river ice, permafrost & sub-sea permafrost, and so on. Under the ongoing climate warming, the cryosphere has been shrinking at an accelerating rate. Most of glaciers retreat and lose their mass loss. The active layer of permafrost deepens and soil temperature rises. All these changes have profoundly altered the regional or even global hydrology and water quality, and further act on the feedbacks to climate change. Besides, the rapid cryospheric changes are also reshaping the terrain and landforms. This is also closely related to the stability of the ecosystem. Meanwhile, cryosphere contains large of chemicals as “pool”, such as carbon, nitrogen, mercury and other pollutants, making it an important linkage for the global biogeochemical cycles, posing potential risks on the cryosphere ecological security.
How to cite: Zhang, Y.: Cryospheric change and ecological security, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1661, https://doi.org/10.5194/egusphere-egu26-1661, 2026.
The Arctic is increasingly influenced by extreme events both in environmental forcing, and in the response in the cryosphere. Still, the mechanisms linking short-lived events in the different component of the Arctic system (atmosphere, land ice, ocean and sea ice) remain poorly understood. Within the ESA-funded ARCTEX project we use a range of EO datasets and model outputs to identify extreme events and their impact on three different ice caps/ glaciers in the Arctic: The Flade Isblink and Austfonna ice caps and Nioghalvfjerdsfjorden outlet glacier.
Here, we present our findings over the Flade Isblink Ice cap in Northeastern Greenland. We present a comprehensive suite of EO-derived data sets over and around the ice cap, and wavelet analysis to identify extreme events, periodicity and regime shifts in these time series. One finding is the surge of Marsk Stig Bræ, which was initiated after 2021, and the subsequent response in the surface topography of the ice cap. We examine the potential drivers and consequences of this surge, with particular emphasis on the possible coupling between glacier dynamics, the drainage of a nearby subglacial lake, sea ice variability and ocean temperatures. Using a multi-sensor Earth Observation approach combined with regional climate model output, we analyse the temporal evolution of ice velocity, surface elevation, meltwater production, and subglacial hydrology from 2011 to 2025. This study demonstrates the value of integrated, high-temporal-resolution EO datasets for resolving rapid cryospheric change.
How to cite: Sandberg Sørensen, L., Scanlan, K., Fredensborg, R., Andersen, N., Arildsen, R., Kirby, J., and Kruse, M.: Drivers and impacts of extreme events on Flade Isblink ice cap., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17756, https://doi.org/10.5194/egusphere-egu26-17756, 2026.
Glaciers in the European Alps are retreating and thinning rapidly due to increasing atmospheric temperatures with expected far reaching implications on water availability, biodiversity, and local economy. Given their critical role as freshwater reservoirs and climate indicators, monitoring glacier changes is essential. Uncrewed Aerial Vehicles (UAVs) provide high-resolution, cost-effective observations that bridge the gap between sparse field measurements and coarse satellite data, enabling detailed assessment of glacier surface dynamics. In this study, a UAV- derived high-resolution dataset spanning the years 2017 – 2025 is evaluated to study the frontal spatio-temporal dynamics of the Morteratsch-Pers glacier complex. Surface elevation and surface velocities are derived and combined with reconstructed ice thickness fields (based on radar measurements) to reconstruct the glacier surface mass balance over time. The results are then compared to in-situ stake observations to assess the influence of features such as debris cover and collapsing ice caves, not captured with the local measurements, on frontal retreat patterns.
How to cite: Henning, K., Van Tricht, L., Izeboud, M., van Breedam, J., Verhaegen, Y., Hoessli, L., Kneib, M., Huybrechts, P., and Zekollari, H.: Quantifying frontal disintegration processes at Morteratsch-Pers glacier complex using high-resolution UAV imagery (2017–2025), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4464, https://doi.org/10.5194/egusphere-egu26-4464, 2026.
Tropical Andean glaciers provide an important flux of freshwater to communities living both in high-altitude Cordillera and population centres downstream in countries such as Peru and Bolivia. Glacier recession threatens the sustainability of these water resources, and accurate modelling of future glacier behaviour is required to manage water stress in the region. These models must capture all processes contributing significantly to overall glacier mass budgets. Here we examine supraglacial pond and ice cliff development on three clean-ice glaciers in the Cordillera Vilcanota, Peru and their overall contribution to glacier mass balance. Whilst such features are common and well-studied on debris-covered glaciers, their development on debris-free glaciers has not been examined in detail. We use high-resolution contemporary and historical satellite imagery and repeat drone surveys to examine surface structure and geometry change over three glaciers during 1977–2024. We show how cliff and pond formation is driven by aspect-dependent surface melt of crevasse walls. These features act as ice loss hotspots, which enhance glacier net mass loss by ∼10% despite accounting for <5% glacier surface area. Incorporation of such amplified ice loss processes should be a priority for glacier model advances to achieve more accurate projections of future tropical glacier recession.
How to cite: King, O., Montoya, N., Davies, B., Matthews, T., Vargas, M., Ghuffar, S., Gribbin, T., Perry, B., Rado, M., McNabb, R., Nicholson, L., and Ely, J.: The impact of supraglacial ice cliff and pond formation on debris-free, tropical glacier mass loss, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6845, https://doi.org/10.5194/egusphere-egu26-6845, 2026.
In many mountain regions, glaciers constitute an essential freshwater reservoir and represent a critical water supply for downstream populations during droughts. Moreover, glacier mass changes provide a direct and valuable indicator of ongoing climate change. While long-term glacier mass loss is well documented, the drivers of temporal variability in regional glacier mass balance remain poorly constrained, despite their importance for understanding regional glacier–climate interactions.
Satellite gravimetry missions Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) provide direct observations of mass variations at monthly timescales with global coverage over the past two decades. Here, we use GRACE/-FO Level-3 products to estimate glacier mass changes over some regions of the Randolph Glacier Inventory (RGI v6.0) and to investigate their sensitivity to climate variability. Two GRACE/-FO solutions are considered: a solution based on Multichannel Singular Spectrum Analysis (M-SSA), and the SAGSA ensemble solution combining products from multiple processing centers. Signal leakage and separation effects related to the coarse spatial resolution of gravimetry are mitigated using geometry-based approaches, enabling regional mass balance estimates.
Monthly region-wide glacier mass balance are then used to explore relationships with key climate-related drivers, with an initial focus on near-surface air temperature and precipitation derived from the ERA5 reanalysis. This study aims to explore the links between glacier mass variability and climate-related drivers using GRACE/GRACE-FO observations.
How to cite: Gauer, L.-M., Berthier, E., and Blazquez, A.: Assessing glacier mass sensitivity to climate variability using GRACE/-FO, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9610, https://doi.org/10.5194/egusphere-egu26-9610, 2026.
High Mountain Asia (HMA) provides crucial water resources to more than 1.5 billion people and accurate quantification of high elevation precipitation in this region is essential for understanding the hydrological cycle, patterns of ongoing climatic change, and water resource management. This is particularly the case in high elevation, glacierised catchments where the interplay of cryospheric and atmospheric processes limits our understanding of current and future water resource availability. The role of precipitation and snow accumulation is critical for the health of glaciers which represent both an important freshwater storage and hydrological buffer to drought conditions. In both present-day and future modelling scenarios, precipitation at both macro and local scales generate some of the greatest uncertainties in glacier response to climate, especially across the distinct hydro-climatic regions of HMA.
We leverage precipitation estimates across several regional gridded products with a high spatial (>= 10 km) and temporal (hourly) resolution to explore their discrepancies over glacierised regions of HMA for the period of 2001-2019. Our analyses demonstrate a substantial disagreement between precipitation datasets in terms of i) their annual and seasonal magnitudes, ii) the fraction of precipitation occurring during the summer/monsoon period, iii) the differences of precipitation amounts between decades, iv) the correlation of precipitation amounts to annual mass balances, v) diurnal precipitation frequency and, vi) dependence on elevation and topographic complexity.
Using the Open Global Glacier Model (OGGM), we demonstrate that the selection of precipitation input data can lead to widely differing interpretations of the role of precipitation as a driver of mass balance variability under a future climate and create substantially different estimations of runoff that exceed the differences due to the choice of climate model.
At catchment scales, the spatial extent and seasonality of precipitation, as well as the representation of specific storm events are all critical for the accurate estimation of glacier energy and mass balance. Fully-physical modelling of well-monitored, glacierised catchments across HMA reveals that the timing of precipitation events can be equally important to the long-term mass balance of glaciers as the monthly amounts of precipitation from different datasets.
Finally, we discuss the regions of greatest disagreement and highlight further investigations linking precipitation and glacier health under present and future climate.
How to cite: Shaw, T., Jouberton, A., Kneib, M., Miles, E., Niwano, M., Fujita, K., Buri, P., and Pellicciotti, F.: Dataset Discrepancies Dominate Present and Future Precipitation-Glacier Relationships Across High Mountain Asia, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11770, https://doi.org/10.5194/egusphere-egu26-11770, 2026.
The Arctic has been warming four times faster than the global mean over the last forty years. In response, the mass loss of glaciers has been accelerating and contributing to global sea-level rise. However, many of the mechanisms of this mass loss process are not well understood, especially the calving dynamics of marine-terminating glaciers, in part due to a lack of high-resolution calving front observations. To address this limitation, we developed a novel automated deep learning framework to automatically detect calving fronts in multimodal satellite imagery, including optical and SAR satellite images from Landsat, Terra-ASTER, Sentinel-2, and Sentinel-1 missions. In total, this provides an approximately four-decade time series of calving dynamics across Arctic glaciers and ice caps. The method was tested and developed initially on the Svalbard archipelago, where we identified widespread calving front retreats during the past four decades, including attribution to climate forcing mechanisms. Here, we have extended the analysis across the entire Arctic to produce a time series that starts in the 1980s with quasi-annual temporal resolution, but achieves sub-monthly sampling from 2014 onward, following the launch of Sentinel-1. This provides both seasonal and inter-annual calving dynamics for almost all marine-terminating glaciers in the Arctic, which have been used to explore and understand the drivers of calving processes.
How to cite: Li, T., Maussion, F., and Bamber, J.: Four decades of pan-Arctic glacier calving fluxes from multimodal satellite imagery, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13133, https://doi.org/10.5194/egusphere-egu26-13133, 2026.
