Glacier Dynamics Research Articles

Calving dynamics at Jakobshavn Isbrae (Sermeq Kujalleq) controlled by local geometry: insights from a 3D Stokes calving model

Abstract We present the first simulations of Jakobshavn Isbrae (Sermeq Kujalleq), west Greenland, using a 3D Stokes calving model that permits unrestricted advance and retreat. Using the position-based crevasse-depth calving law, the model is applied to simulate the calving dynamics of 2016–2017 season when Jakobshavn Isbrae is assumed to be stable because of the presence of a strong proglacial ice mélange. The calving law needs to be adjusted to avoid an underestimation of calving, but once adjusted the calving model simulates seasonal calving dynamics that reflect observed calving-driven retreat very well. We find that a crevasse penetration threshold of 94.5% best matches observations from satellite imagery. Additional, 2-year transient simulations show that although ice mélange is essential to the glacier's winter readvance, when removed, the glacier only retreats a couple of kilometres before reaching a stable position. While the backstress provided by the ice mélange allows the glacier to advance beyond this point, the retreated terminus position is determined by a combination of bed geometry and glacier dynamics. Ultimately, while the ice mélange allows winter readvance, cessation of the well-documented rapid retreat of Jakobshavn Isbrae will be influenced by the bed geometry.

Impact of changes in climate and glacier configurations on runoff from the Langtang River basin, Nepal

Abstract. Climate change is rapidly altering Himalayan glaciers, jeopardizing downstream water resources. This study investigates the impact of changing air temperatures, precipitation, and glacier configurations on streamflow in the Langtang River basin, a vital Himalayan basin. Using a process-based glacio-hydrological model driven by bias-corrected reanalysis data, we simulate streamflow under various scenarios. Results reveal that, while current glacier conditions show increased runoff with higher temperatures and precipitation, future deglaciation scenarios project a decrease in total streamflow, highlighting the complex interplay between climate and glacier dynamics in basin hydrology. These findings emphasize the need for adaptation strategies to ensure water security in the face of evolving Himalayan hydrology.

Regional ice flow piracy following the collapse of Midgaard Glacier in Southeast Greenland

Southeast Greenland contributes significantly to global sea level rise, with mass loss having increased by about 600% over the past 30 years due to enhanced melt and dynamic instabilities of marine-terminating glaciers. Accurate modelling of glacier dynamics is crucial to minimise uncertainties in predictions of future sea level rise, necessitating detailed reconstructions of long-term glacial histories. One key complexity in these models that is not well understood or documented is ice flow piracy, where ice is redirected between catchment basins, significantly influencing regional glacier dynamics and mass balance. Here, we document and characterise the collapse of Midgaard Glacier in Southeast Greenland using a multi-data approach, providing a 90-year record of the area’s complex glacial history. Initiated over 80 years ago, this collapse triggered catchment-scale dynamic changes in several neighbouring glaciers, impacting local glacial stability throughout the 20th century and into the present. Our analysis reveals that catchment-scale ice flow piracy can cause substantial disturbances in mass balance evolution and catchment reconfigurations, independent of climatic conditions. These findings underscore the importance of understanding long-term changes in complex glacier systems to make accurate predictions of future glacial mass loss and associated sea-level rise.

Estimating glacier dynamics and supraglacial lakes together with associated regional hazards using high-resolution datasets in Pamir

Estimating glacier dynamics and supraglacial lakes together with associated regional hazards using high-resolution datasets in Pamir

Dynamic LIA advances hastened the demise of small valley glaciers in central Svalbard

Most small land-terminating glaciers in Svalbard have experienced large recession since the Little Ice Age (LIA) and today are thin, cold, and largely inactive. This likely contrasts to their LIA conditions, but the observational record from that time is sparse. We investigate the evolution of five small glaciers in central Nordenskiöld Land, Svalbard, from the LIA to 2019. Photogrammetric reconstructions and ground penetrating radar are used to reconstruct their geometric changes since 1936, and historical observation, photographs, and geomorphological mapping extend this history to before the 1900s. Our results show that from 1936 to 2019, the study glaciers on average lost 49.6% of their area and 77.4% ± 7.7% of their volume, with the greatest volume loss at Scott Turnerbreen of 91% ± 5%. Four out of these five glaciers strongly indicate a history of surge-like advances near the end of the LIA within one or two decades, and the rate of subsequent mass loss seems connected to their previous dynamics. This apparent switch to high activity during a period of rapid climatic change, could have implications for our understanding of past and future glacier evolution; climate change and highly dynamic glacier responses may be more connected than previously thought.

Rock glacier inventory and predictive modeling in the Mackenzie Mountains: predicting rock glacier likelihood with a generalized additive model

Rock glaciers have been the subject of extensive research in recent years due to their potential to serve as indicators of past and present climate conditions and their potential impacts on water resources. Location and descriptive rock glacier data within the Mackenzie Mountains were used to build a rock glacier inventory that will serve as a valuable resource for future research and monitoring efforts. Additionally, this study maps the likelihood of rock glacier presence using extracted variables in a generalized additive model (GAM). The model incorporates attribute data, including potential incoming solar radiation (PISR), topographic position index (TPI), slope, elevation, and lithology as controls for rock glacier development. Topographic data were compiled for three study regions of the Mackenzie Mountains from a 30 m digital elevation model (DEM). The analysis of the GAM showed that the most significant explanatory variables were PISR, elevation, slope, and TPI. The GAM model had an accuracy of 0.87 with a sensitivity of 0.92. This study provides important insights into the controls, distribution, and dynamics of rock glaciers in the Mackenzie Mountains, as well as both the limitations and the potential of statistical models in predicting their occurrence.

Projected changes of Greenland’s periphery glaciers and ice caps

Abstract Rapid global warming has caused drastic mass loss in Greenland’s peripheral glaciers and ice caps (GICs), contributing to a rise of global sea levels. To better understand future changes under different emission scenarios, we used the Open Global Glacier Model to simulate glacier dynamics and runoff changes from 2015 to 2100. The results show that their area and volume will decrease by 38.88% (SSP1-2.6) to 60.84% (SSP5-8.5) and 47.56% (SSP1-2.6) to 67.10% (SSP5-8.5) by 2100, with regions that have larger glacierized areas and are farther from the ocean experiencing less volume loss. Meanwhile, the predicted surface mass balance of Greenland’s peripheral GICs in 2100 is −0.58 ± 0.92, −1.18 ± 1.13, −2.04 ± 0.79 and −3.16 ± 0.96 m w.e. a−1 under four emission scenarios. The runoff under higher emission scenarios is larger than that under lower emission scenarios, with peak water occurring later in regions that have larger glacierized areas and are farther from the ocean.

The Importance of Solving Subglaciar Hydrology in Modeling Glacier Retreat: A Case Study of Hansbreen, Svalbard

Arctic tidewater glaciers are retreating, serving as key indicators of global warming. This study aims to assess how subglacial hydrology affects glacier front retreat by comparing two glacier–fjord models of the Hansbreen glacier: one incorporating a detailed subglacial hydrology model and another simplifying the subglacial discharge to a single channel centered in the flow line. We first validate the subglacial hydrology model by comparing its discharge channels with observations of plume activity. Simulations conducted from April to December 2010 revealed that the glacier front position aligns more closely with the observations in the coupled model than in the simplified version. Furthermore, the mass loss due to calving and submarine melting is greater in the coupled model, with the calving mass loss reaching 6 Mt by the end of the simulation compared to 4 Mt in the simplified model. These findings highlight the critical role of subglacial hydrology in predicting glacier dynamics and emphasize the importance of detailed modeling in understanding the responses of Arctic tidewater glaciers to climate change.

GNSS reflectometry from low-cost sensors for continuous in situ contemporaneous glacier mass balance and flux divergence

Abstract Recent advances in remote sensing have produced global glacier surface elevation change data. Parsing these elevation change signals into contributions from the climate (i.e. climatic mass balance) and glacier dynamics (i.e. flux divergence) is critical to enhance our process-based understanding of glacier change. In this study, we evaluate three approaches for direct, continuous measurements of the climatic mass balance, flux divergence and elevation change at a site on Gulkana Glacier in Alaska using low-cost global navigation satellite system (GNSS) sensors, GNSS interferometric reflectometry (GNSS-IR), banded ablation stakes with time-lapse cameras and combinations thereof. Cumulative climatic mass balance over the season was 4.85 m and the three approaches were within 0.08 m through early July before the snowpack melted, and within 0.28 m through mid-August. The flux divergence increased from 0.52 ± 0.03 cm d−1 before June 3 to about 0.73 cm d−1 after June 27. We demonstrate a single GNSS system fixed atop an ablation stake can measure contemporaneous climatic mass balance, flux divergence and elevation change based on the antenna's position and GNSS-IR techniques. The ability of these systems to measure glacier mass balance and flux divergence offers unique opportunities for year-round observations on mountain glaciers in the future.

Assessment and Application of Multi-Source Precipitation Products in Cold Regions Based on the Improved SWAT Model

In hydrological modeling, the accuracy of precipitation data and the reflection of the model’s physical mechanisms are crucial for accurately describing hydrological processes. Identifying reliable data sources and exploring reasonable hydrological evolution mechanisms for hydrology and water resources research in high-altitude mountainous regions with sparse stations and limited data constitute a significant challenge and focus in the field of hydrology. This study focuses on the Yarkant River Basin in Xinjiang, which originates from glaciers and contains a substantial amount of meltwater runoff. A dynamic glacier melt module considering the synergistic effects of multiple meteorological factors was developed and integrated into the original Soil and Water Assessment Tool (SWAT) model. Four precipitation datasets (ERA5-land, MSWEP, CMA V2.0, and CHM-PRE) were selected to train the model, including remote sensing precipitation products and station-interpolated precipitation data. The applicability of the improved SWAT model and precipitation datasets in the source region of the Yarkant River was evaluated and analyzed using statistical indicators, hydrological characteristic values, and watershed runoff simulation effectiveness. The optimal dataset was further used to analyze glacier evolution characteristics in the basin. The results revealed the following: (1) The improved model fills the gap in glacier runoff simulation with respect to the original SWAT model, with the simulation results more closely aligning with the actual runoff variation patterns in the study area, better describing the meltwater runoff process. (2) CMA V2.0 precipitation data has the best applicability in the study area. This is specifically reflected in the rationality of the spatial and temporal distribution patterns of the inverted precipitation, the accuracy observed in capturing precipitation events and actual precipitation characteristics, the goodness of fit in driving hydrological models, and the observed precision in reflecting the composition of watershed runoff, all of which are superior to those pertaining to other precipitation products. (3) The glacier melt calculated using the improved SWAT model informed by CMA V2.0 shows that during the study period, the basin formed a pattern with a positive–negative glacier balance demarcation at 36.5° N, featuring melting at higher latitudes and accumulation at lower latitudes. The results of this study are of significant importance for hydrometeorological applications and hydrological and water resources research in this region.

Comparing the evolution of debris-free and debris-covered glaciers during the end of the Lateglacial and the Holocene in Dudh Koshi basin, Everest region, Nepal

Debris-covered glaciers are very frequent geomorphological features in Khumbu Himal (Nepal). Rock debris on the glacier surface play a significant role in glacier-climate relationships and glacier dynamics. These effects may cause an asynchronous evolution of debris-covered glaciers compared to debris-free glaciers at a multicentennial to millennial scale. Here, we explore this hypothesis by documenting and comparing the multi-millennial Holocene evolution of a debris-free glacier, Sabai glacier, and two debris-covered glaciers, Dig and Huuku glaciers, from adjacent catchments in Dudh Koshi basin (Everest region, Nepal). To do so, we dated rock samples collected from moraine boulders on both debris-covered and debris-free glaciers using the 10Be cosmic ray exposure (CRE) dating method. 10Be CRE ages obtained from 41 moraine boulder samples provide time constraints from ∼13.5 ka to 0.1 ka. While at Dig (debris-covered) and Sabai (debris-free) glaciers, no moraines from the Lateglacial and the Early Holocene are preserved, debris-covered Huuku glacier evidenced a large glacier extent during the Bølling-Allerød and Early Holocene with two moraines dated respectively to ∼13.5 ka and 11 ka, synchronously with most debris-free and debris-covered glaciers in this region. These two glacier advances are concomitant with enhanced monsoon precipitation supporting a qualitative relationship. The absence of debris landforms in the main valley question the nature of Huuku glacier during the Bølling-Allerød and Early Holocene, which could have been either debris-free or covered by a thin debris layer only. During the Mid Holocene, significant differences are observed in the evolution of the two glacier types. The two debris-covered glaciers recorded a significant advance at ∼4.8 ka, synchronous with that observed on other debris-covered glaciers in Khumbu valley. However, such glacier advance during the Mid Holocene was not evidenced on debris-free glaciers in the Dudh Koshi valley. Such a Mid Holocene glacier advance may have a spatial signature with frequent cases reported from both types of glaciers in the western part of High Mountain Asia, which are however infrequent in the arid and semi-arid southern and north-eastern Tibet. During the Late Holocene, both types of glaciers evolved similarly again, with moraines spanning the last two millennia, including the Little Ice Age, concomitant with enhanced monsoon precipitation.

What do trees reveal about the sliding of the lateral moraine of the Belvedere Glacier (western Italian Alps)?

The debris-covered Belvedere Glacier is an iconic place for investigating glacier dynamics and geomorphological processes typical of high mountain environments. Moreover, being located in an area highly suited to tourism, glacial and geomorphological hazards can evolve into risk scenarios. Particular attention has been paid during this research to the surge-type event that occurred at the beginning of the 21st century, and to the recent sliding of a lateral moraine nearby the chairlift station. Tree sampling was performed (19 trees on the lateral moraine; 10 undisturbed trees), and the results were compared with morphometric measurements on orthophotos of different years. Besides sampling trunks, the six available exposed roots (13 samples) from a tree located along the sliding niche were sampled to identify the exposure time. Morphometric measurements of the touristic trail dislocation indicate a sliding rate of 1.87 m/y – 1.98 m/y (2018–2023), while the regression rate of the sliding niche is 1.70 m/y (2021–2023). The age of trees along the trench is variable (14–49 years), as is the signal of compression wood, enhancing differentially the passage of the surge wave and the subsequent glacier downwasting. The beginning of root exposure occurred between 2017 and 2019, before the effective evidence of large fractures in the ground. Moreover, the roots show traumatic resin ducts in the period between 2020 and 2022, confirming the tree disturbance. In conclusion, the investigated events are recorded differentially in the sampled trees, especially in roots, anticipating the actual commencement of ground failure. A multidisciplinary approach, including remote sensing, field survey, and dendrogeomorphological analysis is essential to define the dynamics of complex systems.

Segmentation of Glacier Area Using U-Net through Landsat Satellite Imagery for Quantification of Glacier Recession and Its Impact on Marine Systems

Glaciers have experienced a global trend of recession within the past century. Quantification of glacier variations using satellite imagery has been of great interest due to the importance of glaciers as freshwater resources and as indicators of climate change. Spatiotemporal glacier dynamics must be monitored to quantify glacier variations. The potential methods to quantify spatiotemporal glacier dynamics with increasing complexity levels include detecting the terminus location, measuring the length of the glacier from the accumulation zone to the terminus, quantifying the glacier surface area, and measuring glacier volume. Although some deep learning methods designed purposefully for glacier boundary segmentation have achieved acceptable results, these models are often localized to the region where their training data were acquired and further rely on the training sets that were often curated manually to highlight glacial regions. Due to the very large number of glaciers, it is practically impossible to perform a worldwide study of glacier dynamics using manual methods. As a result, an automated or semi-automated method is highly desirable. The current study has built upon our previous works moving towards identification methods of the 2D glacier profile for glacier area segmentation. In this study, a deep learning method is proposed for segmentation of temporal Landsat images to quantify the glacial region within the Mount Cook/Aoraki massif located in the Southern Alps/Kā Tiritiri o te Moana of New Zealand/Aotearoa. Segmented glacial regions can be further utilized to determine the relationship of their variations due to climate change. This model has demonstrated promising performance while trained on a relatively small dataset. The permanent ice and snow class was accurately segmented at a 92% rate by the proposed model.

A Binned Multilevel Regression Fitting Method for Monitoring Geladandong Glacier Elevation Changes from ICESat-2 Data

ABSTRACT Studying glacier changes is essential for understanding global glacier mass balance, patterns in climate change, and the potential consequences they may have. The glaciers of Geladandong Mountain serve as a crucial water source for the Yangtze River and its downstream regions. Any changes in the glacier at the river source will directly impact the ecological environment and water recycling process downstream. This study presents an approach for monitoring Geladandong Mountain glacier elevation changes using ICESat-2 data combined with a Binned Multilevel Regression Fitting Method (BMRFM). We analysed multi-year ICESat-2 data, considering various topographic features, to understand glaciers’ annual and seasonal elevation changes. Our research reveals significant spatial heterogeneity in glacier elevation changes, influenced by altitude, slope, and aspect factors. It demonstrates the effectiveness of ICESat-2 in glacier monitoring, offering insights into the impacts of climate change on glacier dynamics. Moreover, the results indicate a predominant trend of ongoing melting at lower altitudes, with a small amount of accretion at higher elevations. Over the last two decades, the overall elevation change rate is −0.23 ± 0.12 metres per year. Seasonal analysis shows substantial glacier thickening from April to August, primarily due to increased precipitation offsetting elevated temperatures. This study offers a robust method for monitoring glaciers using satellite data, thereby advancing the precision and reliability of glacier research.

Geomorphological and historical records of the surge-type behaviour of Hansbreen (Svalbard)

Abstract This paper presents geomorphological and historical records of the surge-type behaviour of Hansbreen, one of the most studied tidewater glaciers in Svalbard. The surge-type behaviour of the glacier has not been considered before due to the lack of evidence of this phenomenon. We integrate geomorphological mapping of the terrestrial and submarine forefields with historical data from the 19th and 20th centuries to reconstruct the glacier dynamics and identify the possible timing of surging. Landform assemblages are representative of the surging glacier landsystem, including crevasse-squeeze ridges (CSRs) and submarine streamlined glacial lineations. Abundant CSRs in the outer part of the terrestrial forefield were also documented in the 1980s, but most have been obliterated since then. We suggest the identified surge landsystem was produced during a surge of Hansbreen detected from photographs taken during the Austro-Hungarian expedition in 1872. Historical photogrammetric photos from the Norwegian expedition in 1918 revealed surge-diagnostic features in the glacier surface, including a folded medial moraine and a dense, complex network of crevasses. A potential next surge remains questionable in the following decades due to the low-lying accumulation area of the main stream hindering the mass build-up, but potential surges of the tributary glaciers should not be excluded.

WITHDRAWN: Surging dynamics of unnamed glaciers at the Abi Gamin Peak in the central Himalayas

Surge-type glaciers in the Himalayas have been extensively documented, however, understanding of the mechanisms behind glacier surges remain limited. Herein, based on multi-source remote sensing data, we systematically investigated the characteristics and subglacial processes of the unnamed glacier at Abi Gamin Peak in central Himalayas. Our approach integrated optical stereo photogrammetry, feature tracking, visual interpretation, and glacier velocity decomposition. Our study reveals that the glacier surge was initiated in August 2019 and lasted for less than six months, with rapid acceleration and deceleration phases. During the surge, the glacier transported approximately 0.233 km3 of mass from higher to lower elevations, leading to a thickness increase of >70 m at the glacier terminus. The glacier terminus advanced by >800 m, accompanied by significant expansion of the crevasses. Furthermore, we quantitatively revealed the evolution of basal stresses, strain rates, and sliding velocities during the surge, indirectly characterising the influence of water on it. We contend that the surge in this glacier was primarily driven by subglacial sliding induced by glacier surface meltwater. Significant changes in regional climate serve as external factors that perturb the glacial dynamic equilibrium. The observed characteristics of the unnamed glacier at Abi Gamin Peak indicate that its surge was controlled by a hydrological switch. Notably, our work contributes to an enhanced understanding of glacier surge mechanisms in High Mountain Asia.

Accelerated glacier mass loss in the mid-latitude Eurasia from 2019 to 2022 revealed by ICESat-2

The dynamics of glaciers serve as one of the most important indicators of climate change. Whilst current research has primarily concentrated on long-term interannual glacier mass balance and its response to climate change, glaciers may respond more rapidly to climate change, highlighting the urgent need for intra-annual mass balance estimations. Investigating seasonal or short-term variations in glacier mass balance not only enhances our understanding of the interactions between glaciers and the climate system but also provides crucial data for water resource management and ecological protection. The ICESat-2 and NASADEM datasets were used to estimate the inter- and intra-annual glacier mass balance changes in the mid-latitude Eurasia from 2019 to 2022. Additionally, the response of glacier mass balance to regional air temperature and precipitation values was analysed using ERA5-Land data and multiple regression analysis, respectively. From 2019 to 2022, glacier mass loss in mid-latitude Eurasia reached −45.02 ± 34.21 Gt per year, contributing to a global sea-level rise of 0.12 ± 0.09 mm per year. The glacier melt rate in the study area from 2019 to 2022 was 2.33 times higher than that from 2000 to 2019. With the exception of the Western Kunlun region, which experienced a weak accumulation rate of 0.04 ± 0.35 m w.e. per year, all other areas experienced ablation states. Seasonal mass balance responds differently to temperature and precipitation variations across seasons: higher temperatures in different seasons lead to more negative mass balances, while increased winter and spring precipitation can slow down glacier melt. Air temperature dominates the glacier mass balance changes in the study area. The intense heat in 2022 raised average glacier temperatures by 1.04 °C compared to 2019–2021, resulting in a more negative mass balance and an increased ice loss of −0.34 ± 1.01 m w.e. per year (−35.07 ± 103.22 Gt per year). This analysis indicates that glacier mass balance is highly sensitive to climate change, even on a seasonal scale. Moreover, the high precision and spatiotemporal resolution ICESat-2 data can facilitate the investigation of large-scale glacier mass balance on short time scales.

Dynamics and internal structure of a rock glacier: Inferring relationships from the combined use of differential synthetic aperture radar interferometry, electrical resistivity tomography and ground‐penetrating radar

AbstractRock glaciers are characteristic landforms in alpine environments originating from the movement of permanently frozen ground. Hereby, rock glacier velocity (RGV) is an important parameter for understanding the effects of climate change on mountain permafrost. Although understanding of rock glacier dynamics has increased during the last decades, linking small‐scale surface kinematics to sub‐surface properties and heterogeneities remains a challenge. To address this gap, we conducted geophysical surveys (electrical resistivity tomography [ERT] and ground‐penetrating radar [GPR]) along two profile lines of 450 and 950 m in length on a rock glacier in the Central Swiss Alps. Additionally, RGV was derived from Sentinel‐1 differential synthetic aperture radar interferometry (DInSAR) to quantify annual east–west displacement and elevation change as well as seasonal acceleration during the snow‐free summer months with a ground sampling distance of 5 m. Our results show that movement angle and seasonality are highly associated with different patterns in sub‐surface structure. These different movement patterns are linked to subunits of different morphological origins. Thereby, we can upscale the geophysical results based on the DInSAR surface movement parameters and outline an area within the study site probably affected by ice of glacial origin. Hence, DInSAR movement angle and seasonality can help to bring local sub‐surface information derived from time‐consuming geophysical investigations into the spatial domain. In this way, a better understanding of the current morphodynamics as well as the past and future evolution of the landform can be reached. Applying the approach to other sites with available geophysical investigations could enhance our knowledge about systematic links between surface kinematics and the internal structure of rock glaciers and other ice‐rich glacial and peri‐glacial landforms, as well as their response to a warming climate.

Glacier Surges Controlled by the Close Interplay Between Subglacial Friction and Drainage

AbstractThe flow of glaciers and ice sheets is largely influenced by friction at the ice‐bed interface that can trigger rapid changes in glacier motion ranging from seasonal velocity variations to cyclic surge instabilities or even devastating glacier collapse. This wide range of transient glacier dynamics is currently not captured by models, and its implications for long‐term glacier evolution are uncertain. This highlights the need of developing improved descriptions for processes that occur at the glacier bed. Here, we present a model that describes the evolution of basal friction inspired by a “rate and state” approach, coupled to models of subglacial drainage and glacier flow, and investigate how these couplings affect the dynamics of glaciers. We show that a wide range of sliding behavior results from a feedback loop between subglacial drainage efficiency and friction which depends on the evolution of a frictional state that can be interpreted as the degree of cavitation or till porosity for hard and soft beds, respectively. In our simulations, we find that glaciers are susceptible to surging if they exhibit a transition to velocity weakening friction associated with a poor sensitivity of the drainage capacity to the frictional state. This potential materializes if the local topography and mass balance create the conditions for high water pressure to build up in an area sufficiently large to exceed a critical length. We advocate accounting for feedback loops between friction and drainage as a promising avenue for better understanding dynamical instabilities of glaciers and ice sheets.

New evidence of glacier advances during Lateglacial Interstadial deciphered from facies evolution in proglacial lacustrine basins of the Maurienne Valley, French Alps

Sedimentological analysis of glaciolacustrine deposit in the French Alps provides an opportunity to elucidate poorly understood glacier fluctuations during the Lateglacial Interstadial. This study focuses on two proglacial lacustrine basins in the Maurienne Valley, Le Verney and Lanslebourg, recording sediment deposition during the Lateglacial. Sedimentological and soft sediment deformation analyses were conducted on these glaciolacustrine sedimentary deposits to constrain the dynamic of the Arc glacier. At Le Verney, the sedimentary succession records the deposition of a proglacial subaquatic fan under supercritical conditions, transitioning to a Gilbert delta-type sedimentation, indicating glacier retreat. Fluid overpressure, shear deformations, and compressional stresses found within Gilbert delta-type sediment marks a subsequent glacier advance. In the Lanslebourg basin, sedimentary deposits display supercritical and subcritical conditions, separated by deposition under a hydraulic jump characteristic of ice contact delta. In this area, glacier advance is recorded by a more proximal condition toward the top of the sedimentary succession, along with a transition to a subglacial condition. These findings reveal glacier advances during the Bølling-Allerød Interstadial, providing the first evidence of glacier re-advances in the French northern Alps during this warming period. This result highlights the complex interactions between local climate, glacier dynamics, and topography.