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
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Alexander H. Jarosch, Eyjólfur Magnússon, Krista Hannesdóttir, Joaquín M. C. Belart, and Finnur Pálsson
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-101, https://doi.org/10.5194/tc-2023-101, 2023
Revised manuscript accepted for TC
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Geothermally active regions beneath glaciers do not only influence local ice flow as well as the mass balance of glaciers, they can 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 as well as monitor their 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
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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
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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
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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.
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
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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.
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The Cryosphere, 17, 3955–3986, https://doi.org/10.5194/tc-17-3955-2023, https://doi.org/10.5194/tc-17-3955-2023, 2023
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The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-101, https://doi.org/10.5194/tc-2023-101, 2023
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Geothermally active regions beneath glaciers do not only influence local ice flow as well as the mass balance of glaciers, they can 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 as well as monitor their evolution.
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EGUsphere, https://doi.org/10.5194/egusphere-2022-1442, https://doi.org/10.5194/egusphere-2022-1442, 2023
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We studied groundwater near outlet glaciers of the main Icelandic icecap. 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 glacial context is crucial to forecast the evolution under climate change of water resources and of potential floods and landslides hazards.
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
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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.
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Andreas Türke, Marie D. Jackson, Wolfgang Bach, Wolf-Achim Kahl, Brian Grzybowski, Beau Marshall, Magnús T. Gudmundsson, and Steffen Leth Jørgensen
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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
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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
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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
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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
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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
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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
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Related subject area
Discipline: Glaciers | Subject: Glacier Hydrology
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Christian Schoof
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The Cryosphere, 17, 2607–2624, https://doi.org/10.5194/tc-17-2607-2023, https://doi.org/10.5194/tc-17-2607-2023, 2023
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Alexis Caro, Thomas Condom, Antoine Rabatel, Nicolas Champollion, Nicolás García, and Freddy Saavedra
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The glacier runoff changes are still unknown in most of the Andes, thereby increasing uncertainties in estimating water availability mainly in the dry season. Here, we simulate glacier evolution and related runoff changes across the Andes between 2000–2019. Our results show a glacier reduction in 93 % of the catchments, inducing an increase in the glacier melt of 12 %. These results can be downloaded and coupled with discharge measurements in each catchment.
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The Cryosphere, 16, 3101–3121, https://doi.org/10.5194/tc-16-3101-2022, https://doi.org/10.5194/tc-16-3101-2022, 2022
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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.
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The Cryosphere, 16, 1031–1056, https://doi.org/10.5194/tc-16-1031-2022, https://doi.org/10.5194/tc-16-1031-2022, 2022
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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
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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
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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
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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
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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
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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
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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
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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.
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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...
