Articles | Volume 15, issue 8
https://doi.org/10.5194/tc-15-3731-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-15-3731-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
12 Aug 2021
Research article |
| 12 Aug 2021
| 12 Aug 2021
Development of a subglacial lake monitored with radio-echo sounding: case study from the eastern Skaftá cauldron in the Vatnajökull ice cap, Iceland
Institute of Earth Sciences, University of Iceland, Reykjavík,
IS-102, Iceland
Finnur Pálsson
Institute of Earth Sciences, University of Iceland, Reykjavík,
IS-102, Iceland
Magnús T. Gudmundsson
Institute of Earth Sciences, University of Iceland, Reykjavík,
IS-102, Iceland
Thórdís Högnadóttir
Institute of Earth Sciences, University of Iceland, Reykjavík,
IS-102, Iceland
Cristian Rossi
Remote Sensing Technology Institute, German Aerospace Center (DLR), 82234
Wessling, Germany
Thorsteinn Thorsteinsson
Icelandic Meteorological Office, Reykjavík, IS-105, Iceland
Benedikt G. Ófeigsson
Icelandic Meteorological Office, Reykjavík, IS-105, Iceland
Erik Sturkell
Department of Earth Sciences, University of Gothenburg,
Box 460, 405 30, Gothenburg, Sweden
Tómas Jóhannesson
Icelandic Meteorological Office, Reykjavík, IS-105, Iceland
Related authors
Greta Hoe Wells, Þorsteinn Sæmundsson, Finnur Pálsson, Guðfinna Aðalgeirsdóttir, Eyjólfur Magnússon, Reginald L. Hermanns, and Snævarr Guðmundsson
EGUsphere, https://doi.org/10.5194/egusphere-2024-2002, https://doi.org/10.5194/egusphere-2024-2002, 2024
Short summary
Short summary
Glacier retreat elevates the risk of landslides released into proglacial lakes, which can trigger glacial lake outburst floods (GLOFs). This study maps proglacial lake evolution and GLOF hazard scenarios at Fjallsjökull glacier, Iceland. Lake volume increased from 1945–2021 and is estimated to triple over the next century. Three slopes are prone to landslides that may trigger GLOFs. Results will mitigate flood hazard at this popular tourism site and advance GLOF research in Iceland and globally.
Alexander H. Jarosch, Eyjólfur Magnússon, Krista Hannesdóttir, Joaquín M. C. Belart, and Finnur Pálsson
The Cryosphere, 18, 2443–2454, https://doi.org/10.5194/tc-18-2443-2024, https://doi.org/10.5194/tc-18-2443-2024, 2024
Short summary
Short summary
Geothermally active regions beneath glaciers not only influence local ice flow as well as the mass balance of glaciers but also control changes of subglacial water reservoirs and possible subsequent glacier lake outburst floods. In Iceland, such outburst floods impose danger to people and infrastructure and are therefore monitored. We present a novel computer-simulation-supported method to estimate the activity of such geothermal areas and to monitor its evolution.
Joaquín M. C. Belart, Etienne Berthier, Eyjólfur Magnússon, Leif S. Anderson, Finnur Pálsson, Thorsteinn Thorsteinsson, Ian M. Howat, Guðfinna Aðalgeirsdóttir, Tómas Jóhannesson, and Alexander H. Jarosch
The Cryosphere, 11, 1501–1517, https://doi.org/10.5194/tc-11-1501-2017, https://doi.org/10.5194/tc-11-1501-2017, 2017
Short summary
Short summary
Sub-meter satellite stereo images (Pléiades and WorldView2) are used to accurately measure snow accumulation and winter mass balance of Drangajökull ice cap. This is done by creating and comparing accurate digital elevation models. A glacier-wide geodetic mass balance of 3.33 ± 0.23 m w.e. is derived between October 2014 and May 2015. This method could be easily transposable to remote glaciated areas where seasonal mass balance measurements (especially winter accumulation) are lacking.
E. Magnússon, J. Muñoz-Cobo Belart, F. Pálsson, H. Ágústsson, and P. Crochet
The Cryosphere, 10, 159–177, https://doi.org/10.5194/tc-10-159-2016, https://doi.org/10.5194/tc-10-159-2016, 2016
Short summary
Short summary
We demonstrate the opportunities given by high resolution digital elevation models (DEMs) to improve procedures for obtaining mass balance records from archives of aerial photographs. We also describe a geostatistical approach to estimate uncertainty of elevation changes derived by differencing DEMs. This method is more statistically robust than other described in the literature. Our study highlights a common tendency of overestimating this uncertainty, downgrading geodetic mass balance records.
E. Berthier, C. Vincent, E. Magnússon, Á. Þ. Gunnlaugsson, P. Pitte, E. Le Meur, M. Masiokas, L. Ruiz, F. Pálsson, J. M. C. Belart, and P. Wagnon
The Cryosphere, 8, 2275–2291, https://doi.org/10.5194/tc-8-2275-2014, https://doi.org/10.5194/tc-8-2275-2014, 2014
Short summary
Short summary
We evaluate the potential of Pléiades sub-meter satellite stereo imagery to derive digital elevation models (DEMs) of glaciers and their elevation changes. The vertical precision of the DEMs is ±1 m, even ±0.5m on the flat glacier tongues. Similar precision levels are obtained in accumulation areas. Comparison of a Pléiades DEM with a SPOT5 DEM reveals the strongly negative region-wide mass balances of glaciers in the Mont Blanc area (-1.04±0.23m at 1 water equivalent) during 2003-2012.
Greta Hoe Wells, Þorsteinn Sæmundsson, Finnur Pálsson, Guðfinna Aðalgeirsdóttir, Eyjólfur Magnússon, Reginald L. Hermanns, and Snævarr Guðmundsson
EGUsphere, https://doi.org/10.5194/egusphere-2024-2002, https://doi.org/10.5194/egusphere-2024-2002, 2024
Short summary
Short summary
Glacier retreat elevates the risk of landslides released into proglacial lakes, which can trigger glacial lake outburst floods (GLOFs). This study maps proglacial lake evolution and GLOF hazard scenarios at Fjallsjökull glacier, Iceland. Lake volume increased from 1945–2021 and is estimated to triple over the next century. Three slopes are prone to landslides that may trigger GLOFs. Results will mitigate flood hazard at this popular tourism site and advance GLOF research in Iceland and globally.
Aude Vincent, Clémence Daigre, Ophélie Fischer, Guðfinna Aðalgeirsdóttir, Sophie Violette, Jane Hart, Snævarr Guðmundsson, and Finnur Pálsson
Hydrol. Earth Syst. Sci., 28, 3475–3494, https://doi.org/10.5194/hess-28-3475-2024, https://doi.org/10.5194/hess-28-3475-2024, 2024
Short summary
Short summary
We studied groundwater near outlet glaciers of the main Icelandic ice cap. We acquired new data in the field. Two distinct groundwater compartments and their characteristics are identified. We demonstrate the glacial melt recharge impact on the groundwater dynamic. Knowing groundwater systems in a glacial context is crucial to forecast the evolution under climate change of water resources and of potential flood and landslide hazards.
Alexander H. Jarosch, Eyjólfur Magnússon, Krista Hannesdóttir, Joaquín M. C. Belart, and Finnur Pálsson
The Cryosphere, 18, 2443–2454, https://doi.org/10.5194/tc-18-2443-2024, https://doi.org/10.5194/tc-18-2443-2024, 2024
Short summary
Short summary
Geothermally active regions beneath glaciers not only influence local ice flow as well as the mass balance of glaciers but also control changes of subglacial water reservoirs and possible subsequent glacier lake outburst floods. In Iceland, such outburst floods impose danger to people and infrastructure and are therefore monitored. We present a novel computer-simulation-supported method to estimate the activity of such geothermal areas and to monitor its evolution.
Eva P. S. Eibl, Kristin S. Vogfjörd, Benedikt G. Ófeigsson, Matthew J. Roberts, Christopher J. Bean, Morgan T. Jones, Bergur H. Bergsson, Sebastian Heimann, and Thoralf Dietrich
Earth Surf. Dynam., 11, 933–959, https://doi.org/10.5194/esurf-11-933-2023, https://doi.org/10.5194/esurf-11-933-2023, 2023
Short summary
Short summary
Floods draining beneath an ice cap are hazardous events that generate six different short- or long-lasting types of seismic signals. We use these signals to see the collapse of the ice once the water has left the lake, the propagation of the flood front to the terminus, hydrothermal explosions and boiling in the bedrock beneath the drained lake, and increased water flow at rapids in the glacial river. We can thus track the flood and assess the associated hazards better in future flooding events.
Andri Gunnarsson, Sigurdur M. Gardarsson, and Finnur Pálsson
The Cryosphere, 17, 3955–3986, https://doi.org/10.5194/tc-17-3955-2023, https://doi.org/10.5194/tc-17-3955-2023, 2023
Short summary
Short summary
A model was developed with the possibility of utilizing satellite-derived daily surface albedo driven by high-resolution climate data to estimate the surface energy balance (SEB) for all Icelandic glaciers for the period 2000–2021.
Andri Gunnarsson, Sigurdur M. Gardarsson, Finnur Pálsson, Tómas Jóhannesson, and Óli G. B. Sveinsson
The Cryosphere, 15, 547–570, https://doi.org/10.5194/tc-15-547-2021, https://doi.org/10.5194/tc-15-547-2021, 2021
Short summary
Short summary
Surface albedo quantifies the fraction of the sunlight reflected by the surface of the Earth. During the melt season in the Northern Hemisphere solar energy absorbed by snow- and ice-covered surfaces is mainly controlled by surface albedo. For Icelandic glaciers, air temperature and surface albedo are the dominating factors governing annual variability of glacier surface melt. Satellite data from the MODIS sensor are used to create a data set spanning the glacier melt season.
Tómas Jóhannesson, Jón Kristinn Helgason, and Sigríður Sif Gylfadóttir
Earth Surf. Dynam., 8, 173–175, https://doi.org/10.5194/esurf-8-173-2020, https://doi.org/10.5194/esurf-8-173-2020, 2020
Marie D. Jackson, Magnús T. Gudmundsson, Tobias B. Weisenberger, J. Michael Rhodes, Andri Stefánsson, Barbara I. Kleine, Peter C. Lippert, Joshua M. Marquardt, Hannah I. Reynolds, Jochem Kück, Viggó T. Marteinsson, Pauline Vannier, Wolfgang Bach, Amel Barich, Pauline Bergsten, Julia G. Bryce, Piergiulio Cappelletti, Samantha Couper, M. Florencia Fahnestock, Carolyn F. Gorny, Carla Grimaldi, Marco Groh, Ágúst Gudmundsson, Ágúst T. Gunnlaugsson, Cédric Hamlin, Thórdís Högnadóttir, Kristján Jónasson, Sigurdur S. Jónsson, Steffen L. Jørgensen, Alexandra M. Klonowski, Beau Marshall, Erica Massey, Jocelyn McPhie, James G. Moore, Einar S. Ólafsson, Solveig L. Onstad, Velveth Perez, Simon Prause, Snorri P. Snorrason, Andreas Türke, James D. L. White, and Bernd Zimanowski
Sci. Dril., 25, 35–46, https://doi.org/10.5194/sd-25-35-2019, https://doi.org/10.5194/sd-25-35-2019, 2019
Short summary
Short summary
Three new cored boreholes through Surtsey volcano, an isolated island in southeastern Iceland, provide fresh insights into understanding how explosive submarine volcanism and the earliest alteration of basaltic deposits proceed in a pristine oceanic environment. The still-hot volcano was first sampled through a drill core in 1979. The time-lapse drill cores record the changing geochemical, mineralogical, microbiological, and material properties of the basalt 50 years after eruptions terminated.
Andreas Türke, Marie D. Jackson, Wolfgang Bach, Wolf-Achim Kahl, Brian Grzybowski, Beau Marshall, Magnús T. Gudmundsson, and Steffen Leth Jørgensen
Sci. Dril., 25, 57–62, https://doi.org/10.5194/sd-25-57-2019, https://doi.org/10.5194/sd-25-57-2019, 2019
Giri Gopalan, Birgir Hrafnkelsson, Guðfinna Aðalgeirsdóttir, Alexander H. Jarosch, and Finnur Pálsson
The Cryosphere, 12, 2229–2248, https://doi.org/10.5194/tc-12-2229-2018, https://doi.org/10.5194/tc-12-2229-2018, 2018
Short summary
Short summary
Geophysical systems can often contain scientific parameters whose values are uncertain, complex underlying dynamics, and field measurements with errors. These components are naturally modeled together within what is known as a Bayesian hierarchical model (BHM). This paper constructs such a model for shallow glaciers based on an approximation of the underlying dynamics. The evaluation of this model is aided by the use of exact analytical solutions from the literature.
Louise Steffensen Schmidt, Guðfinna Aðalgeirsdóttir, Sverrir Guðmundsson, Peter L. Langen, Finnur Pálsson, Ruth Mottram, Simon Gascoin, and Helgi Björnsson
The Cryosphere, 11, 1665–1684, https://doi.org/10.5194/tc-11-1665-2017, https://doi.org/10.5194/tc-11-1665-2017, 2017
Short summary
Short summary
The regional climate model HIRHAM5 is evaluated over Vatnajökull, Iceland, using automatic weather stations and mass balance observations from 1995 to 2014. From this we asses whether the model can be used to reconstruct the mass balance of the glacier. We find that the simulated energy balance is underestimated overall, but it has been improved by using a new albedo scheme. The specific mass balance is reconstructed back to 1980, thus expanding on the observational records of the mass balance.
Joaquín M. C. Belart, Etienne Berthier, Eyjólfur Magnússon, Leif S. Anderson, Finnur Pálsson, Thorsteinn Thorsteinsson, Ian M. Howat, Guðfinna Aðalgeirsdóttir, Tómas Jóhannesson, and Alexander H. Jarosch
The Cryosphere, 11, 1501–1517, https://doi.org/10.5194/tc-11-1501-2017, https://doi.org/10.5194/tc-11-1501-2017, 2017
Short summary
Short summary
Sub-meter satellite stereo images (Pléiades and WorldView2) are used to accurately measure snow accumulation and winter mass balance of Drangajökull ice cap. This is done by creating and comparing accurate digital elevation models. A glacier-wide geodetic mass balance of 3.33 ± 0.23 m w.e. is derived between October 2014 and May 2015. This method could be easily transposable to remote glaciated areas where seasonal mass balance measurements (especially winter accumulation) are lacking.
Monika Wittmann, Christine Dorothea Groot Zwaaftink, Louise Steffensen Schmidt, Sverrir Guðmundsson, Finnur Pálsson, Olafur Arnalds, Helgi Björnsson, Throstur Thorsteinsson, and Andreas Stohl
The Cryosphere, 11, 741–754, https://doi.org/10.5194/tc-11-741-2017, https://doi.org/10.5194/tc-11-741-2017, 2017
Short summary
Short summary
This work includes a study on the effects of dust deposition on the mass balance of Brúarjökull, an outlet glacier of Vatnajökull, Iceland's largest ice cap. A model was used to simulate dust deposition on the glacier, and these periods of dust were compared to albedo measurements at two weather stations on Brúarjökull to evaluate the dust impact. We determine the influence of dust events on the snow albedo and the surface energy balance.
E. Magnússon, J. Muñoz-Cobo Belart, F. Pálsson, H. Ágústsson, and P. Crochet
The Cryosphere, 10, 159–177, https://doi.org/10.5194/tc-10-159-2016, https://doi.org/10.5194/tc-10-159-2016, 2016
Short summary
Short summary
We demonstrate the opportunities given by high resolution digital elevation models (DEMs) to improve procedures for obtaining mass balance records from archives of aerial photographs. We also describe a geostatistical approach to estimate uncertainty of elevation changes derived by differencing DEMs. This method is more statistically robust than other described in the literature. Our study highlights a common tendency of overestimating this uncertainty, downgrading geodetic mass balance records.
M. D. Jackson, M. T. Gudmundsson, W. Bach, P. Cappelletti, N. J. Coleman, M. Ivarsson, K. Jónasson, S. L. Jørgensen, V. Marteinsson, J. McPhie, J. G. Moore, D. Nielson, J. M. Rhodes, C. Rispoli, P. Schiffman, A. Stefánsson, A. Türke, T. Vanorio, T. B. Weisenberger, J. D. L. White, R. Zierenberg, and B. Zimanowski
Sci. Dril., 20, 51–58, https://doi.org/10.5194/sd-20-51-2015, https://doi.org/10.5194/sd-20-51-2015, 2015
Short summary
Short summary
A new drilling program at Surtsey Volcano, a 50-year-old oceanic island and UNESCO World Heritage site in Iceland, will undertake interdisciplinary investigations of rift zone volcanism, dynamic hydrothermal mineral assemblages in basaltic tephra, and subterrestrial microbial colonization and succession in altered tephra and hydrothermal fluids. Long-term monitoring of evolving hydrothermal and biological processes will occur through installation of a 200m deep Surtsey subsurface observatory.
E. Berthier, C. Vincent, E. Magnússon, Á. Þ. Gunnlaugsson, P. Pitte, E. Le Meur, M. Masiokas, L. Ruiz, F. Pálsson, J. M. C. Belart, and P. Wagnon
The Cryosphere, 8, 2275–2291, https://doi.org/10.5194/tc-8-2275-2014, https://doi.org/10.5194/tc-8-2275-2014, 2014
Short summary
Short summary
We evaluate the potential of Pléiades sub-meter satellite stereo imagery to derive digital elevation models (DEMs) of glaciers and their elevation changes. The vertical precision of the DEMs is ±1 m, even ±0.5m on the flat glacier tongues. Similar precision levels are obtained in accumulation areas. Comparison of a Pléiades DEM with a SPOT5 DEM reveals the strongly negative region-wide mass balances of glaciers in the Mont Blanc area (-1.04±0.23m at 1 water equivalent) during 2003-2012.
Related subject area
Discipline: Glaciers | Subject: Glacier Hydrology
Hydrological response of Andean catchments to recent glacier mass loss
Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland
Characterizing sub-glacial hydrology using radar simulations
Velocity variations and hydrological drainage at Baltoro Glacier, Pakistan
Seasonal to decadal dynamics of supraglacial lakes on debris-covered glaciers in the Khumbu region, Nepal
A conceptual model for glacial lake bathymetric distribution
The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws
The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 2: A dynamic viscoelastic model
The impact of surface melt rate and catchment characteristics on Greenland Ice Sheet moulin inputs
Modeling saline fluid flow through subglacial ice-walled channels and the impact of density on fluid flux
Evaporation over a glacial lake in Antarctica
A local model of snow–firn dynamics and application to the Colle Gnifetti site
Accumulation of legacy fallout radionuclides in cryoconite on Isfallsglaciären (Arctic Sweden) and their downstream spatial distribution
Drainage of an ice-dammed lake through a supraglacial stream: hydraulics and thermodynamics
Geophysical constraints on the properties of a subglacial lake in northwest Greenland
Gulf of Alaska ice-marginal lake area change over the Landsat record and potential physical controls
Sensitivity of subglacial drainage to water supply distribution at the Kongsfjord basin, Svalbard
Buoyant calving and ice-contact lake evolution at Pasterze Glacier (Austria) in the period 1998–2019
An analysis of instabilities and limit cycles in glacier-dammed reservoirs
Coupled modelling of subglacial hydrology and calving-front melting at Store Glacier, West Greenland
Channelized, distributed, and disconnected: subglacial drainage under a valley glacier in the Yukon
Alexis Caro, Thomas Condom, Antoine Rabatel, Nicolas Champollion, Nicolás García, and Freddy Saavedra
The Cryosphere, 18, 2487–2507, https://doi.org/10.5194/tc-18-2487-2024, https://doi.org/10.5194/tc-18-2487-2024, 2024
Short summary
Short summary
The glacier runoff changes are still unknown in most of the Andean catchments, thereby increasing uncertainties in estimating water availability, especially during the dry season. Here, we simulate glacier evolution and related glacier runoff changes across the Andes between 2000 and 2019. Our results indicate a glacier reduction in 93 % of the catchments, leading to a 12 % increase in glacier melt. These results can be downloaded and integrated with discharge measurements in each catchment.
Katrina Lutz, Lily Bever, Christian Sommer, Angelika Humbert, Mirko Scheinert, and Matthias Braun
EGUsphere, https://doi.org/10.5194/egusphere-2024-1244, https://doi.org/10.5194/egusphere-2024-1244, 2024
Short summary
Short summary
The estimation of the amount of water found within supraglacial lakes is important for understanding the amount of water lost from glaciers each year. Here, we develop two new methods for estimating supraglacial lake volume that can be easily applied on a large scale. Furthermore, we compare these methods to two previously developed methods in order to determine when is best to use each method. Finally, three of these methods are applied to peak melt dates over an area in Northeast Greenland.
Chris Pierce, Christopher Gerekos, Mark Skidmore, Lucas Beem, Don Blankenship, Won Sang Lee, Ed Adams, Choon-Ki Lee, and Jamey Stutz
The Cryosphere, 18, 1495–1515, https://doi.org/10.5194/tc-18-1495-2024, https://doi.org/10.5194/tc-18-1495-2024, 2024
Short summary
Short summary
Water beneath glaciers in Antarctica can influence how the ice slides or melts. Airborne radar can detect this water, which looks bright in radar images. However, common techniques cannot identify the water's size or shape. We used a simulator to show how the radar image changes based on the bed material, size, and shape of the waterbody. This technique was applied to a suspected waterbody beneath Thwaites Glacier. We found it may be consistent with a series of wide, flat canals or a lake.
Anna Wendleder, Jasmin Bramboeck, Jamie Izzard, Thilo Erbertseder, Pablo d'Angelo, Andreas Schmitt, Duncan J. Quincey, Christoph Mayer, and Matthias H. Braun
The Cryosphere, 18, 1085–1103, https://doi.org/10.5194/tc-18-1085-2024, https://doi.org/10.5194/tc-18-1085-2024, 2024
Short summary
Short summary
This study analyses the basal sliding and the hydrological drainage of Baltoro Glacier, Pakistan. The surface velocity was characterized by a spring speed-up, summer peak, and autumn speed-up. Snow melt has the largest impact on the spring speed-up, summer velocity peak, and the transition from inefficient to efficient drainage. Drainage from supraglacial lakes contributed to the fall speed-up. Increased summer temperatures will intensify the magnitude of meltwater and thus surface velocities.
Lucas Zeller, Daniel McGrath, Scott W. McCoy, and Jonathan Jacquet
The Cryosphere, 18, 525–541, https://doi.org/10.5194/tc-18-525-2024, https://doi.org/10.5194/tc-18-525-2024, 2024
Short summary
Short summary
In this study we developed methods for automatically identifying supraglacial lakes in multiple satellite imagery sources for eight glaciers in Nepal. We identified a substantial seasonal variability in lake area, which was as large as the variability seen across entire decades. These complex patterns are not captured in existing regional-scale datasets. Our findings show that this seasonal variability must be accounted for in order to interpret long-term changes in debris-covered glaciers.
Taigang Zhang, Weicai Wang, and Baosheng An
The Cryosphere, 17, 5137–5154, https://doi.org/10.5194/tc-17-5137-2023, https://doi.org/10.5194/tc-17-5137-2023, 2023
Short summary
Short summary
Detailed glacial lake bathymetry surveys are essential for accurate glacial lake outburst flood (GLOF) simulation and risk assessment. We creatively developed a conceptual model for glacial lake bathymetric distribution. The basic idea is that the statistical glacial lake volume–area curves conform to a power-law relationship indicating that the idealized geometric shape of the glacial lake basin should be hemispheres or cones.
Christian Schoof
The Cryosphere, 17, 4797–4815, https://doi.org/10.5194/tc-17-4797-2023, https://doi.org/10.5194/tc-17-4797-2023, 2023
Short summary
Short summary
Computational models that seek to predict the future behaviour of ice sheets and glaciers typically rely on being able to compute the rate at which a glacier slides over its bed. In this paper, I show that the degree to which the glacier bed is
hydraulically connected(how easily water can flow along the glacier bed) plays a central role in determining how fast ice can slide.
Christian Schoof
The Cryosphere, 17, 4817–4836, https://doi.org/10.5194/tc-17-4817-2023, https://doi.org/10.5194/tc-17-4817-2023, 2023
Short summary
Short summary
The subglacial drainage of meltwater plays a major role in regulating glacier and ice sheet flow. In this paper, I construct and solve a mathematical model that describes how connections are made within the subglacial drainage system. This will aid future efforts to predict glacier response to surface melt supply.
Tim Hill and Christine F. Dow
The Cryosphere, 17, 2607–2624, https://doi.org/10.5194/tc-17-2607-2023, https://doi.org/10.5194/tc-17-2607-2023, 2023
Short summary
Short summary
Water flow across the surface of the Greenland Ice Sheet controls the rate of water flow to the glacier bed. Here, we simulate surface water flow for a small catchment on the southwestern Greenland Ice Sheet. Our simulations predict significant differences in the form of surface water flow in high and low melt years depending on the rate and intensity of surface melt. These model outputs will be important in future work assessing the impact of surface water flow on subglacial water pressure.
Amy Jenson, Mark Skidmore, Lucas Beem, Martin Truffer, and Scott McCalla
EGUsphere, https://doi.org/10.5194/egusphere-2023-792, https://doi.org/10.5194/egusphere-2023-792, 2023
Short summary
Short summary
Water in some glacier environments contains salt which increases the density of the fluid and decreases the freezing point of the fluid. As a result, hypersaline lakes can exist in places where freshwater cannot and can contain unique microbiological communities. We model the flow of saline fluid from a subglacial lake through a channel at the glacier bed. The results suggest that fluid with higher salinity reach higher discharge rates compared to fresh water due to increased fluid density.
Elena Shevnina, Miguel Potes, Timo Vihma, Tuomas Naakka, Pankaj Ramji Dhote, and Praveen Kumar Thakur
The Cryosphere, 16, 3101–3121, https://doi.org/10.5194/tc-16-3101-2022, https://doi.org/10.5194/tc-16-3101-2022, 2022
Short summary
Short summary
The evaporation over an ice-free glacial lake was measured in January 2018, and the uncertainties inherent to five indirect methods were quantified. Results show that in summer up to 5 mm of water evaporated daily from the surface of the lake located in Antarctica. The indirect methods underestimated the evaporation over the lake's surface by up to 72 %. The results are important for estimating the evaporation over polar regions where a growing number of glacial lakes have recently been evident.
Fabiola Banfi and Carlo De Michele
The Cryosphere, 16, 1031–1056, https://doi.org/10.5194/tc-16-1031-2022, https://doi.org/10.5194/tc-16-1031-2022, 2022
Short summary
Short summary
Climate changes require a dynamic description of glaciers in hydrological models. In this study we focus on the local modelling of snow and firn. We tested our model at the site of Colle Gnifetti, 4400–4550 m a.s.l. The model shows that wind erodes all the precipitation of the cold months, while snow is in part conserved between April and September since higher temperatures protect snow from erosion. We also compared modelled and observed firn density, obtaining a satisfying agreement.
Caroline C. Clason, Will H. Blake, Nick Selmes, Alex Taylor, Pascal Boeckx, Jessica Kitch, Stephanie C. Mills, Giovanni Baccolo, and Geoffrey E. Millward
The Cryosphere, 15, 5151–5168, https://doi.org/10.5194/tc-15-5151-2021, https://doi.org/10.5194/tc-15-5151-2021, 2021
Short summary
Short summary
Our paper presents results of sample collection and subsequent geochemical analyses from the glaciated Isfallsglaciären catchment in Arctic Sweden. The data suggest that material found on the surface of glaciers,
cryoconite, is very efficient at accumulating products of nuclear fallout transported in the atmosphere following events such as the Chernobyl disaster. We investigate how this compares with samples in the downstream environment and consider potential environmental implications.
Christophe Ogier, Mauro A. Werder, Matthias Huss, Isabelle Kull, David Hodel, and Daniel Farinotti
The Cryosphere, 15, 5133–5150, https://doi.org/10.5194/tc-15-5133-2021, https://doi.org/10.5194/tc-15-5133-2021, 2021
Short summary
Short summary
Glacier-dammed lakes are prone to draining rapidly when the ice dam breaks and constitute a serious threat to populations downstream. Such a lake drainage can proceed through an open-air channel at the glacier surface. In this study, we present what we believe to be the most complete dataset to date of an ice-dammed lake drainage through such an open-air channel. We provide new insights for future glacier-dammed lake drainage modelling studies and hazard assessments.
Ross Maguire, Nicholas Schmerr, Erin Pettit, Kiya Riverman, Christyna Gardner, Daniella N. DellaGiustina, Brad Avenson, Natalie Wagner, Angela G. Marusiak, Namrah Habib, Juliette I. Broadbeck, Veronica J. Bray, and Samuel H. Bailey
The Cryosphere, 15, 3279–3291, https://doi.org/10.5194/tc-15-3279-2021, https://doi.org/10.5194/tc-15-3279-2021, 2021
Short summary
Short summary
In the last decade, airborne radar surveys have revealed the presence of lakes below the Greenland ice sheet. However, little is known about their properties, including their depth and the volume of water they store. We performed a ground-based geophysics survey in northwestern Greenland and, for the first time, were able to image the depth of a subglacial lake and estimate its volume. Our findings have implications for the thermal state and stability of the ice sheet in northwest Greenland.
Hannah R. Field, William H. Armstrong, and Matthias Huss
The Cryosphere, 15, 3255–3278, https://doi.org/10.5194/tc-15-3255-2021, https://doi.org/10.5194/tc-15-3255-2021, 2021
Short summary
Short summary
The growth of a glacier lake alters the hydrology, ecology, and glaciology of its surrounding region. We investigate modern glacier lake area change across northwestern North America using repeat satellite imagery. Broadly, we find that lakes downstream from glaciers grew, while lakes dammed by glaciers shrunk. Our results suggest that the shape of the landscape surrounding a glacier lake plays a larger role in determining how quickly a lake changes than climatic or glaciologic factors.
Chloé Scholzen, Thomas V. Schuler, and Adrien Gilbert
The Cryosphere, 15, 2719–2738, https://doi.org/10.5194/tc-15-2719-2021, https://doi.org/10.5194/tc-15-2719-2021, 2021
Short summary
Short summary
We use a two-dimensional model of water flow below the glaciers in Kongsfjord, Svalbard, to investigate how different processes of surface-to-bed meltwater transfer affect subglacial hydraulic conditions. The latter are important for the sliding motion of glaciers, which in some cases exhibit huge variations. Our findings indicate that the glaciers in our study area undergo substantial sliding because water is poorly evacuated from their base, with limited influence from the surface hydrology.
Andreas Kellerer-Pirklbauer, Michael Avian, Douglas I. Benn, Felix Bernsteiner, Philipp Krisch, and Christian Ziesler
The Cryosphere, 15, 1237–1258, https://doi.org/10.5194/tc-15-1237-2021, https://doi.org/10.5194/tc-15-1237-2021, 2021
Short summary
Short summary
Present climate warming leads to glacier recession and formation of lakes. We studied the nature and rate of lake evolution in the period 1998–2019 at Pasterze Glacier, Austria. We detected for instance several large-scale and rapidly occurring ice-breakup events from below the water level. This process, previously not reported from the European Alps, might play an important role at alpine glaciers in the future as many glaciers are expected to recede into valley basins allowing lake formation.
Christian Schoof
The Cryosphere, 14, 3175–3194, https://doi.org/10.5194/tc-14-3175-2020, https://doi.org/10.5194/tc-14-3175-2020, 2020
Short summary
Short summary
Glacier lake outburst floods are major glacial hazards in which ice-dammed reservoirs rapidly drain, often in a recurring fashion. The main flood phase typically involves a growing channel being eroded into ice by water flow. What is poorly understood is how that channel first comes into being. In this paper, I investigate how an under-ice drainage system composed of small, naturally occurring voids can turn into a channel and how this can explain the cyclical behaviour of outburst floods.
Samuel J. Cook, Poul Christoffersen, Joe Todd, Donald Slater, and Nolwenn Chauché
The Cryosphere, 14, 905–924, https://doi.org/10.5194/tc-14-905-2020, https://doi.org/10.5194/tc-14-905-2020, 2020
Short summary
Short summary
This paper models how water flows beneath a large Greenlandic glacier and how the structure of the drainage system it flows in changes over time. We also look at how this affects melting driven by freshwater plumes at the glacier front, as well as the implications for glacier flow and sea-level rise. We find an active drainage system and plumes exist year round, contradicting previous assumptions and suggesting more melting may not slow the glacier down, unlike at other sites in Greenland.
Camilo Rada and Christian Schoof
The Cryosphere, 12, 2609–2636, https://doi.org/10.5194/tc-12-2609-2018, https://doi.org/10.5194/tc-12-2609-2018, 2018
Short summary
Short summary
We analyse a large glacier borehole pressure dataset and provide a holistic view of the observations, suggesting a consistent picture of the evolution of the subglacial drainage system. Some aspects are consistent with the established understanding and others ones are not. We propose that most of the inconsistencies arise from the capacity of some areas of the bed to become hydraulically isolated. We present an adaptation of an existing drainage model that incorporates this phenomena.
Cited articles
Åström, J. A., Riikilä, T. I., Tallinen, T., Zwinger, T., Benn, D., Moore, J. C., and Timonen, J.: A particle based simulation model for glacier dynamics, The Cryosphere, 7, 1591–1602, https://doi.org/10.5194/tc-7-1591-2013, 2013.
Bell, R. E., Studinger, M., Shuman, C. A., Fahnestock, M. A., and Joughin,
I.: Large subglacial lakes in East Antarctica at the onset of fast-flowing
ice streams, Nature, 445, 904–907, https://doi.org/10.1038/nature05554, 2007.
Björnsson, H.: The cause of jökulhlaups in the Skaftá river,
Vatnajökull, Jökull, 27, 71–78, 1977.
Björnsson, H.: Hydrology of ice caps in volcanic regions,
Reykjavík, Vísindafélag Íslendinga, 45, 139 pp.,
1988.
Björnsson, H.: Jökulhlaups in Iceland: Prediction, characteristics
and simulation, Ann. Glaciol., 16, 95–106, https://doi.org/10.3189/1992AoG16-1-95-106,
1992.
Björnsson, H.: Subglacial lakes and jökulhlaups in Iceland, Global Planet. Change, 35, 255–271, https://doi.org/10.1016/S0921-8181(02)00130-3, 2003.
Björnsson, H. and Pálsson, F.: Radio-echo soundings on Icelandic
temperate glaciers: History of techniques and findings, Ann. Glaciol.,
61, 25–34, https://doi.org/10.1017/aog.2020.10, 2020.
Carter, S. P., Blankenship, D. D., Peters, M. E., Young, D. A., Holt, J. W.,
and Morse, D. L.: Radar-based subglacial lake classification in Antarctica,
Geochem. Geophy. Geosy., 8, Q03016, https://doi.org/10.1029/2006GC001408, 2007.
Das, S. B., Joughin, I., Behn, M. D., Howat, I. M., King, M. A., Lizarralde,
D., and Bhatia, M. P.: Fracture propagation to the base of the Greenland Ice
Sheet during supraglacial lake drainage, Science, 320, 778–781,
https://doi.org/10.1126/science.1153360, 2008.
Egilson, D., Roberts, M. J., Pagneux, E., Jensen, E. H., Guðmundsson, M.
T., Jóhannesson, T., Jónsson, M. Á., Zóphóníasson,
S., Björnsson, B. B., Þórarinsdóttir, T., and
Karlsdóttir, S.: Hættumat vegna jökulhlaupa í Skaftá,
(Skaftá river: Assessment of jökulhlaup hazards,
Report VÍ-2018-016, Icelandic Meteorological Office, 60 pp., 2018 (in Icelandic).
Eibl, E. P. S., Bean, C. J., Einarsson, B., Pálsson, F., and Vogfjörd
K. S.: Seismic ground vibrations give advanced early-warning of subglacial
floods, Nat. Commun. 11, 2504, https://doi.org/10.1038/s41467-020-15744-5, 2020.
Einarsson, B., Magnússon, E., Roberts, M. J., Pálsson, F.,
Thorsteinsson, T., and Jóhannesson, T.: A spectrum of jökulhlaup
dynamics revealed by GPS measurements of glacier surface motion, Ann.
Glaciol., 57, 47–61, https://doi.org/10.1017/aog.2016.8, 2016.
Einarsson, B., Jóhannesson, T., Thorsteinsson, T., Gaidos, E., and
Zwinger, T.: Subglacial flood path development during a rapidly rising
jökulhlaup from the western Skaftá cauldron, Vatnajökull,
Iceland, J. Glaciol., 63, 670–682, https://doi.org/10.1017/jog.2017.33, 2017.
Fricker, H. A., Scambos, T., Bindschadler, R., and Padman, L.: An Active
Subglacial Water System in West Antarctica Mapped from Space, Science,
315, 1544–1548, https://doi.org/10.1126/science.1136897, 2007.
Gaidos, E., Jóhannesson, T., Einarsson, B., Thorsteinsson, Th., Amend,
J. P., and Skidmore, M.: Après nous, le déluge: A human-triggered
jökulhlaup from a subglacial lake, Geophys. Res. Lett., 47,
e2020GL089876, https://doi.org/10.1029/2020GL089876, 2020.
Galeczka, I., Oelkers E., and Gislason S.: The chemistry and element fluxes
of the July 2011 Múlakvísl and Kaldakvísl glacial floods,
Iceland, J. Volcanol. Geoth. Res., 273, 41–57,
https://doi.org/10.1016/j.jvolgeores.2013.12.004, 2014.
Gray, L., Joughin, I., Tulaczyk, S., Spikes, V. B., Bindschadler, R., and
Jezek, K.: Evidence for subglacial water transport in the West Antarctic Ice
Sheet through three-dimensional satellite radar interferometry, Geophys.
Res. Lett., 32, L03501, https://doi.org/10.1029/2004GL021387, 2005.
Gudmundsson, M. T.: The Grímsvötn caldera, Vatnajökull:
Subglacial topography and structure of caldera infill, Jökull, 39,
1–19, 1989.
Gudmundsson, M. T. and Högnadóttir, Th.: Skaftárkatlar –
Yfirborð og vatnsstaða, available at: http://jardvis.hi.is/skaftarkatlar_yfirbord_og_vatnsstada, last access: 9 July 2021.
Gudmundsson, M. T., Björnsson, H., and Pálsson, F.: Changes in
jökulhlaup sizes in Grímsvötn, Vatnajökull, Iceland,
1934–91, deduced from in-situ measurements of subglacial lake volume, J.
Glaciol., 41, 263–272, https://doi.org/10.3189/S0022143000016166, 1995.
Guðmundsson, M. T., Larsen, G., Þórðarson, Þ.:
Grímsvötn, in: Sólnes, J., Sigmundsson, F., and Bessason, B.,
(Eds.), Náttúruvá á Íslandi, Viðlagatrygging
Íslands/Háskólaútgáfan, 235–251, ISBN: 978-9979-54-943-7, 2013a.
Gudmundsson, M.T., Þórðarson, Þ., Larsen, G., Einarsson, P.,
Höskuldsson, Á., and Imsland, P.: Undir Vatnajökli, in:
Náttúruvá á Íslandi, edited by: Sólnes, J., Sigmundsson, F., and Bessason, B., Viðlagatrygging
Íslands/Háskólaútgáfan, 263–277, ISBN: 978-9979-54-943-7, 2013b.
Gudmundsson, M. T., Jónsdóttir, K., Hooper, A., Holohan, E. P.,
Halldórsson, S. A., Ófeigsson, B. G., Cesca, S., Vogfjörd, K.
S., Sigmundsson, F., Högnadóttir, Th., Einarsson, P., Sigmarsson,
O., Jarosch, A. H., Jónasson, K., Magnússon, E., Hreinsdóttir,
S., Bagnardi, M., Parks, M. M., Hjörleifsdóttir, V., Pálsson,
F., Walter, T. R., Schöpfer, M. P. J., Heimann, S., Reynolds, H. I.,
Dumont, S., Bali, E., Gudfinnsson, G. H., Dahm, T., Roberts, M. J., Hensch,
M., Belart, J. M. C., Spaans, K., Jakobsson, S., Gudmundsson, G. B.,
Fridriksdóttir, H. M., Drouin, V., Dürig, T., Adalgeirsdóttir,
G., Riishuus, M. S., Pedersen, G. B. M., Boeckel, T. van, Oddsson, B.,
Pfeffer, M. A., Barsotti, S., Bergsson, B., Donovan, A., Burton, M. R., and
Aiuppa, A.: Gradual caldera collapse at Bárdarbunga volcano, Iceland
regulated by lateral magma outflow, Science, 353, aaf8988, https://doi.org/10.1126/science.aaf8988, 2016.
Guðmundsson, M. T., Magnússon, E., Högnadóttir, Þ.,
Pálsson F., and Rossi, C.: Hættumat vegna jökulhlaupa í
Skaftá. Skaftárkatlar – saga og þróun 1938–2018, Icelandic
Meteorological Office and Institute of Earth Sciences, University of
Iceland, Report, 62 pp., ISSN 1670-8261, 2018.
Jóhannesson, T., Thorsteinsson, T., Stefánsson, A., Gaidos, E. J.,
and Einarsson, B.: Circulation and thermodynamics in a subglacial geothermal
lake under the Western Skaftá cauldron of the Vatnajökull ice cap,
Iceland, Geophys. Res. Lett., 34, L19502, https://doi.org/10.1029/2007GL030686, 2007.
Jónsson, M. Á., Þórarinsdóttir, T., Pagneux, E.,
Björnsson, B. B., Egilson, D., Jóhannesson T., and Roberts M. J.:
Hættumat vegna jökulhlaupa í Skaftá. Kvörðun
straumfræðilíkans, Icelandic Meteorological Office, Report, 51 pp.,
ISSN 1670-8261, 2018.
Langley, K., Kohler, J., Matsuoka, K., Sinisalo, A., Scambos, T., Neumann,
T., Muto, A., Winther, J.-G., and Albert, M.: Recovery Lakes, East
Antarctica: Radar assessment of sub-glacial water extent, Geophys. Res.
Lett., 38, L05501, https://doi.org/10.1029/2010GL046094, 2011.
Lapazaran, J. J., Otero, J., Martín-Español, A., and Navarro, F.
J.: On the errors involved in ice-thickness estimates I: Ground-penetrating
radar measurement errors, J. Glaciol., 62, 1008–1020,
https://doi.org/10.1017/jog.2016.93, 2016.
Magnússon, E., Björnsson, H., Rott, H., and Pálsson, F.: Reduced glacier sliding caused by persistent drainage from a subglacial lake, The Cryosphere, 4, 13–20, https://doi.org/10.5194/tc-4-13-2010, 2010.
Magnússon, E., Pálsson, F., Guðmundsson, M. T., Belart, J. M.
C., and Högnadóttir Þ.: Hvað sýna
íssjármælingar undir sigkötlum Mýrdalsjökuls, Tech.
Report, Institute of Earth Sciences, University of Iceland, 39 pp., 2017.
Magnússon, E., Pálsson, F., Jarosch, A. H., van Boeckel, T.,
Hannesdóttir, H., and Belart, J. M. C.: The bedrock and tephra layer
topography within the glacier filled Katla caldera, Iceland, deduced from
dense RES-survey, Jökull, 71, 39–70, https://doi.org/10.33799/jokull2021.71.039, 2021.
Mingo, L. and Flowers, G. E.: Instruments and Methods: An integrated
lightweight ice-penetrating radar system, J. Glaciol., 56, 709–714,
https://doi.org/10.3189/002214310793146179, 2010.
Moran, M. L., Greenfield, R. J., Arcone, S. A., and Delaney, A. J.:
Delineation of a complexly dipping temperate glacier bed using short-pulse
radar arrays, J. Glaciol., 46, 274–286,
https://doi.org/10.3189/172756500781832882, 2000.
Murray, T., Stuart, G. W., Fry, M., Gamble, N. G., and Crabtree, M. D.:
Englacial water distribution in a temperate glacier from surface and
borehole radar velocity analysis, J. Glaciol., 46, 389–398,
https://doi.org/10.3189/172756500781833188, 2000.
Porter, C., Morin, P., Howat, I., Noh, M.-J., Bates, B., Peterman, K.,
Keesey, S., Schlenk, M., Gardiner, J., Tomko, K., Willis, M., Kelleher, C.,
Cloutier, M., Husby, E., Foga, S., Nakamura, H., Platson, M., Wethington Jr.,
M., Williamson, C., Bauer, G., Enos, J., Arnold, G., Kramer, W., Becker,
P., Doshi, A., D'Souza, C., Cummens, P., Laurier, F., and Bojesen, M.:
ArcticDEM, V1, Harvard Dataverse, https://doi.org/10.7910/DVN/OHHUKH, 2018.
Reynolds, H. I., Gudmundsson, M. T., Högnadóttir, T., and
Pálsson, F.: Thermal power of Grímsvötn, Iceland, from 1998 to
2016: quantifying the effects of volcanic activity and geothermal anomalies,
J. Volcanol. Geoth. Res., 358, 184–193, https://doi.org/10.1016/j.jvolgeores.2018.04.019,
2018.
Robin, G. de Q., Evans, S., and Bailey, J. T.: Interpretation of radio echo
sounding in polar ice sheets, Philos. Trans. R. Soc., 265,
437–505, https://doi.org/10.1098/rsta.1969.0063, 1969.
Robin, G. de Q., Swithinbank, C., and Smith, B. M. E.: Radio echo
exploration of the Antarctic ice sheet, in: International Symposium on Antarctic
Glaciological Exploration (ISAGE), edited by: Gow, A. J., Keeler, C., Langway, C. C., and Weeks, W. F., International Association of Scientific Hydrology, Hanover, New Hampshire, 3–7 September
1968, 97–115, 1970.
Rossi, C., Gonzalez, F. R., Fritz, T., Yague-Martinez, N., and Eineder, M.:
TanDEM-X calibrated raw DEM generation. ISPRS Journal of Photogrammetry and
Remote Sensing, 73, 12–20, https://doi.org/10.1016/j.isprsjprs.2012.05.014, 2012
Rossi, C., Minet, C., Fritz, T., Eineder, M., and Bamler, R.: Temporal
monitoring of subglacial volcanoes with TanDEM-X – Application to the
2014–2015 eruption within the Barðarbunga volcanic system, Iceland,
Remote Sens. Environ., 181, 186–197, https://doi.org/10.1016/j.rse.2016.04.003, 2016.
Schneider, W. A.: Integral formulation for migration in two and three
dimensions, Geophysics, 43, 49–76, https://doi.org/10.1190/1.1440828, 1978.
Siegert, M. J., Ross, N., Corr, H., Smith, B., Jordan, T., Bingham, R. G., Ferraccioli, F., Rippin, D. M., and Le Brocq, A.: Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet, The Cryosphere, 8, 15–24, https://doi.org/10.5194/tc-8-15-2014, 2014.
Smith, B. E., Fricker, H. A., Joughin, I. R., and Tulaczyk, S.: An inventory
of active subglacial lakes in Antarctica detected by ICESat (2003–2008), J.
Glaciol., 55, 573–595, https://doi.org/10.3189/002214309789470879, 2009.
Smith, B. M. E. and Evans, S.: Radio Echo Sounding: Absorption and
Scattering by Water Inclusion and Ice Lenses, J. Glaciol., 11, 133–146,
https://doi.org/10.3189/S0022143000022541, 1972.
Stearns, L. A., Smith, B. E., and Hamilton, G. S.: Increased flow speed on a
large East Antarctic outlet glacier caused by subglacial floods, Nat.
Geosci., 1, 827–831, https://doi.org/10.1038/ngeo356, 2008.
Thorarinsson, S.: The jökulhlaup from the Katla area in 1955 compared
with other jökulhlaups in Iceland, Jökull, 7, 21–25, 1957.
Thorarinsson, S. and Sigurdsson, S.: Volcano-glaciological investigations
in Iceland during the last decade, Polar Record, 5, 60–66,
https://doi.org/10.1017/S0032247400037190, 1947.
Ultee, L., Meyer, C., and Minchew, B.: Tensile strength of glacial ice
deduced from observations of the 2015 eastern Skaftá cauldron collapse,
Vatnajökull ice cap, Iceland, J. Glaciol., 66, 1024–1033,
https://doi.org/10.1017/jog.2020.65, 2020.
Wadell, H.: Vatnajökull, some studies and observations from the greatest
glacial area in Iceland, Geogr. Ann., 2, 300–323,
doi.org/10.1080/20014422.1920.11880777, 1920.
Zóphóníasson, S.: Rennsli í Skaftárhlaupum 1955–2002
[Discharge in jökulhlaups in Skaftá 1955–2002], Reykjavík,
National Energy Authority, Report SZ-2002/01, 2002.
Short summary
We present a unique insight into the shape and development of a subglacial lake over a 7-year period, using repeated radar survey. The lake collects geothermal meltwater, which is released in semi-regular floods, often referred to as jökulhlaups. The applicability of our survey approach to monitor the water stored in the lake for a better assessment of the potential hazard of jökulhlaups is demonstrated by comparison with independent measurements of released water volume during two jökulhlaups.
We present a unique insight into the shape and development of a subglacial lake over a 7-year...
