Liam S. Taylor

Ice-marginal lakes are increasingly widespread around the Greenland Ice Sheet (GrIS), but their influence on ice dynamics remains poorly constrained. Elsewhere, recent work has shown that ice-contact lakes are more thermally complex than previously thought, with potential implications for rates of melt undercutting and calving losses. Here, we assess the relationship between lake thermal regime and calving frequency at a lake-terminating outlet glacier in west Greenland using in situ observations collected during the summers of 2024 and 2025. Lake water temperature varied across the summer season, exhibiting a distinct warm phase during August characterised by a positive thermal gradient and brief period of stratification. Calving activity was dominated by waterline and collapse events, with event frequency peaking during the warm lake phase. Statistical modelling indicates that this was also the period when lake water temperature and calving frequency were most strongly associated. These findings suggest that intraseasonal changes in lake thermal structure may modulate calving behaviour, likely through enhanced melt undercutting. Overall, we highlight the potential for thermally driven calving to become an increasingly important mechanism of ice-loss at lake-contact margins of the GrIS with continued climate warming, and thus lake warming.

Ice-marginal lakes are increasingly widespread around the Greenland Ice Sheet (GrIS), but their influence on ice dynamics remains poorly constrained. Elsewhere, recent work has shown that ice-contact lakes are more thermally complex than previously thought, with potential implications for rates of melt undercutting and calving losses. Here, we assess the relationship between lake thermal regime and calving frequency at a lake-terminating outlet glacier in west Greenland using in situ observations collected during the summers of 2024 and 2025. Lake water temperature varied across the summer season, exhibiting a distinct warm phase during August characterised by a positive thermal gradient and brief period of stratification. Calving activity was dominated by waterline and collapse events, with event frequency peaking during the warm lake phase. Statistical modelling indicates that this was also the period when lake water temperature and calving frequency were most strongly associated. These findings suggest that intraseasonal changes in lake thermal structure may modulate calving behaviour, likely through enhanced melt undercutting. Overall, we highlight the potential for thermally driven calving to become an increasingly important mechanism of ice-loss at lake-contact margins of the GrIS with continued climate warming, and thus lake warming.

In-situ monitoring of calving process from lake-terminating glaciers in the Himalayas remain scarce, despite being a significant component controlling glacier retreat. Acquiring in-situ measurements are challenging due to harsh terrain and extreme weather conditions, which has typically resulted in the use of expensive, state-of-the-art terrestrial observational systems. Such limitation in data acquiring leads to an incomplete understanding of calving-induced glacial mass loss and retreat. In this study, we evaluate the effectiveness of a low-cost Raspberry-Pi based terrestrial photogrammetry system for annual monitoring of calving from lake-terminating glaciers. We tested the proposed system for monitoring calving at lake-terminating Panchinala-B Glacier, Indian Western Himalayas. The photogrammetry system consists of an array of Raspberry-Pi powered time-lapse cameras, which took multi-view stereo images of the glacier front face over a 12-month period between August 2023 and August 2024. The images were processed in a Structure-from-Motion (SfM) workflow to generate two, annually separated, point clouds. The Multiscale Model-to-Model Cloud Comparison (M3C2) distance of the annually separated point clouds yielded a mean terminus position change (retreat) of 0.88 m, with a mean absolute error of (+/-) 5.8 m. Using the above obtained parameters a calving rate and calving mass flux of 16.3 (+/-) 4.29 m/annum and 0.00017 (+/-) 0.000125 Gt/annum respectively can be quantified. Further, numerous environmental and system design-based challenges were encountered, which affected the quality of the obtained calving estimates. These challenges were carefully understood, and we provide further recommendations for the future use of similar low-cost systems for long-term glacier monitoring, which demonstrate good potential for characterising the magnitude and frequency of calving processes at lake-terminating glaciers.

As Earth’s climate warms, surface melting of the Greenland Ice Sheet has intensified, increasing rates of sea-level rise. Observations and theory indicate that meltwater generated at the ice sheet surface can drain to its bed, where it flows relatively unhindered to the ocean. This understanding of water movement within and beneath ice sheets underpins the theoretical models that are used to make projections of ice sheet change. Here we present evidence of a destructive mode of meltwater drainage in Greenland. Using multiple satellite sources, we show that a 90-million-cubic-metre subglacial flood forced its way upwards from the bed, fracturing the ice sheet, and bursting through the surface. This phenomenon was triggered by the rapid drainage of a subglacial lake and occurred in a region where the ice bed was predicted to be frozen. The resulting flood caused a rapid deceleration of the downstream marine-terminating glacier. Our observations reveal a complex, bi-directional coupling between the ice sheet’s surface and basal hydrological systems and demonstrate that extreme hydrological forcing may occur in regions of predicted cold-based ice. Such processes can impact the ice sheet’s dynamics and structural integrity but are not currently considered in ice sheet models.

Glaciers terminating in lakes typically flow, thin and lose mass more rapidly than those that terminate on land. This is due to a range of thermomechanical processes exerted at the lake-ice interface, where lake waters drive melt-induced undercutting, enable flotation and facilitate calving. In Greenland, ice marginal lakes (IMLs) have increased in size and number over recent decades and now occupy more than 10% of the ice sheet margin. Despite this, very few observations of their effects on ice dynamics exist, meaning they remain largely unaccounted for in models of ice sheet change.Here, we use ITS_LIVE ice surface velocity data and the How et al. (2021) IML inventory to compare the flow characteristics of 102 lake-terminating outlet glaciers and 102 neighboring land-terminating outlet glaciers across the Greenland Ice Sheet (GrIS) during 2017. We find that along-flow decelerations are much less pronounced at lake- versus land-terminating glaciers, and that some lake-terminating glaciers (n = 33) even speed up towards the ice margin. In turn, lake-terminating glaciers are on average 4.6 times faster than their land-terminating counterparts within the terminus region. Moreover, the fastest flowing glaciers are found to terminate in the largest lakes, suggesting that lake influence evolves with lake development. Ultimately, these observations demonstrate the capacity of IMLs to enhance the surface velocity of Greenlandic outlet glaciers, highlighting their potential to accelerate future mass loss from the GrIS.

Immersive Virtual Reality (VR) offers educators an innovative tool to teach geoscience, addressing challenges in conveying the Earth’s 3D characteristics traditionally taught through field visits and experiences that are often inaccessible to many due to socioeconomic, political, and logistical barriers. VR provides an alternative experience, allowing users to virtually explore geological sites beyond physical and situational constraints. Despite its potential, the implementation of geoscience-focused VR lectures remains largely unexplored. As a pioneering case study, this research investigates the usability and motivational impact of VR by developing a fast-paced virtual reality lecture on landslides for middle school students. Approximately 60 students from diverse cultural and educational backgrounds participated. Results revealed that the VR lecture was usable, with key strengths in its ability to engage students and deliver satisfaction. Compared to traditional teaching methods (lecture and hands-on), VR excelled in fostering interest, enjoyment, and perceived choice. This study provides valuable insights into the practical implementation of VR in geoscience education, demonstrating its potential to make geoscience topics more accessible and engaging for diverse student groups. Future research should explore strategies to address usability challenges and enhance the motivational attributes of VR, paving the way for its broader adoption in geoscience educational settings.

Glacier surges are prevalent in the Karakoram and occasionally threaten local residents by inundating land and initiating mass movement events. The Kyagar Glacier is well known for its surge history, and in particular its frequent blocking of the downstream valley, leading to a series of high-magnitude glacial lake outburst floods (GLOFs). Although the surge dynamics of the Kyagar Glacier have been broadly described in the literature, there remains an extensive archive of remote sensing observations that have great potential for revealing specific surge characteristics and their relationship with historic lake outburst floods. In this study, we propose a new perspective on quantifying the surging process using successive digital elevation models (DEMs), which could be applied to other sites where glacier surges are known to occur. Advanced Spaceborne Thermal Emission and Reflection Radiometer DEMs, High Mountain Asia 8-meter DEMs, and the Shuttle Radar Topography Mission DEM were used to characterize surface elevation changes throughout the period from 2000 to 2021. We also used Landsat time series imagery to quantify glacier surface velocities and associated lake changes over the course of two surge events between 1989 and 2021. Using these datasets, we reconstruct the surging process of the Kyagar Glacier in unprecedented detail and find a clear signal of surface uplift over the lower glacier tongue, along with uniformly increasing velocities, associated with the period of surge initiation. Seasonal variations in surface flow are still evident throughout the surge phase, indicating the presence of water at the glacier bed. Surge activity of the Kyagar Glacier is strongly related to the development and drainage of the terminal ice-dammed lake, which itself is controlled by the drainage system beneath the glacier terminus.