Recent Evolution of Supraglacial Lakes on ice shelves in Dronning Maud Land, East Antarctica
Accumulation of meltwater on the surface of ice shelves can have severe impacts on the ice sheet – ice shelf stability regime. Meltwater ponding on ice shelves can cause firn air depletion, flexure, hydrofracture and collapse of shelves that could further lead to increased ice-sheet discharge and se...
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ftcopernicus:oai:publications.copernicus.org:tcd109047 2023-05-15T13:38:41+02:00 Recent Evolution of Supraglacial Lakes on ice shelves in Dronning Maud Land, East Antarctica Mahagaonkar, Anirudha Moholdt, Geir Schuler, Thomas V. 2023-01-23 application/pdf https://doi.org/10.5194/tc-2023-4 https://tc.copernicus.org/preprints/tc-2023-4/ eng eng doi:10.5194/tc-2023-4 https://tc.copernicus.org/preprints/tc-2023-4/ eISSN: 1994-0424 Text 2023 ftcopernicus https://doi.org/10.5194/tc-2023-4 2023-01-30T17:22:43Z Accumulation of meltwater on the surface of ice shelves can have severe impacts on the ice sheet – ice shelf stability regime. Meltwater ponding on ice shelves can cause firn air depletion, flexure, hydrofracture and collapse of shelves that could further lead to increased ice-sheet discharge and sea level rise. Despite recent progress in the mapping of supraglacial lakes around Antarctica, there is still limited understanding of their dynamics, climatic and environmental controls, and their role in the Antarctic ice sheet mass budget. In this study, we track the seasonal and interannual evolution of supraglacial lakes on ice shelves in Dronning Maud Land in East Antarctica. The assessment employs an automatized band-thresholding approach to examine nearly 2500 Landsat-8 and Sentinel-2 scenes captured between November and March from 2014 to 2021. Large networks of supraglacial lakes and streams were identified over the ice shelves Riiser Larsen, Nivlisen and Roi Baudouin, whereas other ice shelves had only smaller areas with isolated ponds (Fimbulisen and Muninisen) or no significant meltwater lakes at all. Despite large interannual variations in surface ponding, in specific melt years the relative extents were mostly consistent between different ice-shelf regions. The peak extents of supraglacial lakes typically occurred in mid-to-late January and varied from 38.19 ± 29.53 km 2 in the low melt-year 2020–2021 to 809.37 ± 206.74 km 2 in the high melt-year 2016–2017, corresponding to water volumes of 0.03 ± 0.02 km 3 and 0.67 ± 0.16 km 3 respectively. Comparison with positive degree days and seasonal temperatures shows considerable correlation with maximum lake extent for some ice shelves, but in total, it cannot explain the large differences in magnitudes of surface ponding over different ice shelves. For instance, melt extents of Fimbulisen and Nivlisen that lie next to each other differ by two orders of magnitude. Our assessments provide important insights into surface hydrology over the region and will be ... Text Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves Copernicus Publications: E-Journals Antarctic Dronning Maud Land East Antarctica Fimbulisen ENVELOPE(-0.500,-0.500,-70.750,-70.750) Muninisen ENVELOPE(20.340,20.340,-70.340,-70.340) Nivlisen ENVELOPE(11.000,11.000,-70.333,-70.333) Riiser-Larsen ENVELOPE(50.667,50.667,-66.783,-66.783) Roi Baudouin ENVELOPE(24.461,24.461,-70.438,-70.438) The Antarctic |
institution |
Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Accumulation of meltwater on the surface of ice shelves can have severe impacts on the ice sheet – ice shelf stability regime. Meltwater ponding on ice shelves can cause firn air depletion, flexure, hydrofracture and collapse of shelves that could further lead to increased ice-sheet discharge and sea level rise. Despite recent progress in the mapping of supraglacial lakes around Antarctica, there is still limited understanding of their dynamics, climatic and environmental controls, and their role in the Antarctic ice sheet mass budget. In this study, we track the seasonal and interannual evolution of supraglacial lakes on ice shelves in Dronning Maud Land in East Antarctica. The assessment employs an automatized band-thresholding approach to examine nearly 2500 Landsat-8 and Sentinel-2 scenes captured between November and March from 2014 to 2021. Large networks of supraglacial lakes and streams were identified over the ice shelves Riiser Larsen, Nivlisen and Roi Baudouin, whereas other ice shelves had only smaller areas with isolated ponds (Fimbulisen and Muninisen) or no significant meltwater lakes at all. Despite large interannual variations in surface ponding, in specific melt years the relative extents were mostly consistent between different ice-shelf regions. The peak extents of supraglacial lakes typically occurred in mid-to-late January and varied from 38.19 ± 29.53 km 2 in the low melt-year 2020–2021 to 809.37 ± 206.74 km 2 in the high melt-year 2016–2017, corresponding to water volumes of 0.03 ± 0.02 km 3 and 0.67 ± 0.16 km 3 respectively. Comparison with positive degree days and seasonal temperatures shows considerable correlation with maximum lake extent for some ice shelves, but in total, it cannot explain the large differences in magnitudes of surface ponding over different ice shelves. For instance, melt extents of Fimbulisen and Nivlisen that lie next to each other differ by two orders of magnitude. Our assessments provide important insights into surface hydrology over the region and will be ... |
format |
Text |
author |
Mahagaonkar, Anirudha Moholdt, Geir Schuler, Thomas V. |
spellingShingle |
Mahagaonkar, Anirudha Moholdt, Geir Schuler, Thomas V. Recent Evolution of Supraglacial Lakes on ice shelves in Dronning Maud Land, East Antarctica |
author_facet |
Mahagaonkar, Anirudha Moholdt, Geir Schuler, Thomas V. |
author_sort |
Mahagaonkar, Anirudha |
title |
Recent Evolution of Supraglacial Lakes on ice shelves in Dronning Maud Land, East Antarctica |
title_short |
Recent Evolution of Supraglacial Lakes on ice shelves in Dronning Maud Land, East Antarctica |
title_full |
Recent Evolution of Supraglacial Lakes on ice shelves in Dronning Maud Land, East Antarctica |
title_fullStr |
Recent Evolution of Supraglacial Lakes on ice shelves in Dronning Maud Land, East Antarctica |
title_full_unstemmed |
Recent Evolution of Supraglacial Lakes on ice shelves in Dronning Maud Land, East Antarctica |
title_sort |
recent evolution of supraglacial lakes on ice shelves in dronning maud land, east antarctica |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-2023-4 https://tc.copernicus.org/preprints/tc-2023-4/ |
long_lat |
ENVELOPE(-0.500,-0.500,-70.750,-70.750) ENVELOPE(20.340,20.340,-70.340,-70.340) ENVELOPE(11.000,11.000,-70.333,-70.333) ENVELOPE(50.667,50.667,-66.783,-66.783) ENVELOPE(24.461,24.461,-70.438,-70.438) |
geographic |
Antarctic Dronning Maud Land East Antarctica Fimbulisen Muninisen Nivlisen Riiser-Larsen Roi Baudouin The Antarctic |
geographic_facet |
Antarctic Dronning Maud Land East Antarctica Fimbulisen Muninisen Nivlisen Riiser-Larsen Roi Baudouin The Antarctic |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2023-4 https://tc.copernicus.org/preprints/tc-2023-4/ |
op_doi |
https://doi.org/10.5194/tc-2023-4 |
_version_ |
1766109834647699456 |