Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice Sheet

<p>Active subglacial lakes beneath the Antarctic Ice Sheet provide insights into the dynamic subglacial environment, with implications for ice-sheet dynamics and mass balance. Most previously identified lakes have been found upstream (<span class="inline-formula"><i>&...

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Main Authors: J. F. Arthur, C. Shackleton, G. Moholdt, K. Matsuoka, J. van Oostveen
Format: Article
Language:English
Published: Copernicus Publications 2025-01-01
Series:The Cryosphere
Online Access:https://tc.copernicus.org/articles/19/375/2025/tc-19-375-2025.pdf
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author J. F. Arthur
C. Shackleton
G. Moholdt
K. Matsuoka
J. van Oostveen
author_facet J. F. Arthur
C. Shackleton
G. Moholdt
K. Matsuoka
J. van Oostveen
author_sort J. F. Arthur
collection DOAJ
description <p>Active subglacial lakes beneath the Antarctic Ice Sheet provide insights into the dynamic subglacial environment, with implications for ice-sheet dynamics and mass balance. Most previously identified lakes have been found upstream (<span class="inline-formula"><i>&gt;</i>100</span> km) of fast-flowing glaciers in West Antarctica, and none have been found in the coastal region of Dronning Maud Land (DML) in East Antarctica. The regional distribution and extent of lakes as well as their timescales and mechanisms of filling–draining activity remain poorly understood. We present local ice surface elevation changes in the coastal DML region that we interpret as unique evidence of seven active subglacial lakes located under slowly moving ice near the grounding line margin. Laser altimetry data from ICESat-2 and ICESat (Ice, Cloud, and Land Elevation Satellites) combined with multi-temporal Reference Digital Elevation Model of Antarctica (REMA) strips reveal that these lakes actively fill and drain over periods of several years. Stochastic analyses of subglacial water routing together with visible surface lineations on ice shelves indicate that these lakes discharge meltwater across the grounding line. Two lakes are within 15 km of the grounding line, while another three are within 54 km. Ice flows 17–172 m a<span class="inline-formula"><sup>−1</sup></span> near these lakes, much slower than the mean ice flow speed near other active lakes within 100 km of the grounding line (303 m a<span class="inline-formula"><sup>−1</sup></span>). Our results improve knowledge of subglacial meltwater dynamics and evolution in this region of East Antarctica and provide new observational data to refine subglacial hydrological models.</p>
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publishDate 2025-01-01
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spelling doaj-art-8b5e6072a93c43e8810dca143b1cfc6c2025-01-28T07:27:16ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242025-01-011937539210.5194/tc-19-375-2025Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice SheetJ. F. Arthur0C. Shackleton1G. Moholdt2K. Matsuoka3J. van Oostveen4Glaciology and Geology section, Norwegian Polar Institute, 9296 Tromsø, NorwayGlaciology and Geology section, Norwegian Polar Institute, 9296 Tromsø, NorwayGlaciology and Geology section, Norwegian Polar Institute, 9296 Tromsø, NorwayGlaciology and Geology section, Norwegian Polar Institute, 9296 Tromsø, NorwayNORCE Norwegian Research Centre, 9294 Tromsø, Norway<p>Active subglacial lakes beneath the Antarctic Ice Sheet provide insights into the dynamic subglacial environment, with implications for ice-sheet dynamics and mass balance. Most previously identified lakes have been found upstream (<span class="inline-formula"><i>&gt;</i>100</span> km) of fast-flowing glaciers in West Antarctica, and none have been found in the coastal region of Dronning Maud Land (DML) in East Antarctica. The regional distribution and extent of lakes as well as their timescales and mechanisms of filling–draining activity remain poorly understood. We present local ice surface elevation changes in the coastal DML region that we interpret as unique evidence of seven active subglacial lakes located under slowly moving ice near the grounding line margin. Laser altimetry data from ICESat-2 and ICESat (Ice, Cloud, and Land Elevation Satellites) combined with multi-temporal Reference Digital Elevation Model of Antarctica (REMA) strips reveal that these lakes actively fill and drain over periods of several years. Stochastic analyses of subglacial water routing together with visible surface lineations on ice shelves indicate that these lakes discharge meltwater across the grounding line. Two lakes are within 15 km of the grounding line, while another three are within 54 km. Ice flows 17–172 m a<span class="inline-formula"><sup>−1</sup></span> near these lakes, much slower than the mean ice flow speed near other active lakes within 100 km of the grounding line (303 m a<span class="inline-formula"><sup>−1</sup></span>). Our results improve knowledge of subglacial meltwater dynamics and evolution in this region of East Antarctica and provide new observational data to refine subglacial hydrological models.</p>https://tc.copernicus.org/articles/19/375/2025/tc-19-375-2025.pdf
spellingShingle J. F. Arthur
C. Shackleton
G. Moholdt
K. Matsuoka
J. van Oostveen
Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice Sheet
The Cryosphere
title Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice Sheet
title_full Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice Sheet
title_fullStr Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice Sheet
title_full_unstemmed Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice Sheet
title_short Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice Sheet
title_sort evidence of active subglacial lakes under a slowly moving coastal region of the antarctic ice sheet
url https://tc.copernicus.org/articles/19/375/2025/tc-19-375-2025.pdf
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