Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica
The Antarctic ice sheet extent in the Weddell Sea embayment (WSE) during the Last Glacial Maximum (LGM; ca. 19–25 calibrated kiloyears before present, ka cal BP) and its subsequent retreat from the shelf are poorly constrained, with two conflicting scenarios being discussed. Today, the modern Brunt...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/428077 2023-05-15T14:02:01+02:00 Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica Arndt, Jan Erik Larter, Robert D. Hillenbrand, Claus-Dieter Sørli, Simon H. Forwick, Matthias Smith, James A. Wacker, Lukas 2020 application/application/pdf https://hdl.handle.net/20.500.11850/428077 https://doi.org/10.3929/ethz-b-000428077 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-14-2115-2020 info:eu-repo/semantics/altIdentifier/wos/000545958000002 http://hdl.handle.net/20.500.11850/428077 doi:10.3929/ethz-b-000428077 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International CC-BY The Cryosphere, 14 (6) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2020 ftethz https://doi.org/20.500.11850/428077 https://doi.org/10.3929/ethz-b-000428077 https://doi.org/10.5194/tc-14-2115-2020 2022-04-25T14:11:55Z The Antarctic ice sheet extent in the Weddell Sea embayment (WSE) during the Last Glacial Maximum (LGM; ca. 19–25 calibrated kiloyears before present, ka cal BP) and its subsequent retreat from the shelf are poorly constrained, with two conflicting scenarios being discussed. Today, the modern Brunt Ice Shelf, the last remaining ice shelf in the northeastern WSE, is only pinned at a single location and recent crevasse development may lead to its rapid disintegration in the near future. We investigated the seafloor morphology on the northeastern WSE shelf and discuss its implications, in combination with marine geological records, to create reconstructions of the past behaviour of this sector of the East Antarctic Ice Sheet (EAIS), including ice–seafloor interactions. Our data show that an ice stream flowed through Stancomb-Wills Trough and acted as the main conduit for EAIS drainage during the LGM in this sector. Post-LGM ice stream retreat occurred stepwise, with at least three documented grounding-line still-stands, and the trough had become free of grounded ice by ∼10.5 ka cal BP. In contrast, slow-flowing ice once covered the shelf in Brunt Basin and extended westwards toward McDonald Bank. During a later time period, only floating ice was present within Brunt Basin, but large “ice slabs” enclosed within the ice shelf occasionally ran aground at the eastern side of McDonald Bank, forming 10 unusual ramp-shaped seabed features. These ramps are the result of temporary ice shelf grounding events buttressing the ice further upstream. To the west of this area, Halley Trough very likely was free of grounded ice during the LGM, representing a potential refuge for benthic shelf fauna at this time. ISSN:1994-0416 ISSN:1994-0424 Article in Journal/Newspaper Antarc* Antarctic Antarctica Brunt Ice Shelf Ice Sheet Ice Shelf The Cryosphere Weddell Sea ETH Zürich Research Collection Antarctic Brunt Basin ENVELOPE(-25.000,-25.000,-75.000,-75.000) Brunt Ice Shelf ENVELOPE(-22.500,-22.500,-74.750,-74.750) East Antarctic Ice Sheet Mcdonald Bank ENVELOPE(-26.583,-26.583,-75.500,-75.500) The Antarctic Weddell Weddell Sea |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
description |
The Antarctic ice sheet extent in the Weddell Sea embayment (WSE) during the Last Glacial Maximum (LGM; ca. 19–25 calibrated kiloyears before present, ka cal BP) and its subsequent retreat from the shelf are poorly constrained, with two conflicting scenarios being discussed. Today, the modern Brunt Ice Shelf, the last remaining ice shelf in the northeastern WSE, is only pinned at a single location and recent crevasse development may lead to its rapid disintegration in the near future. We investigated the seafloor morphology on the northeastern WSE shelf and discuss its implications, in combination with marine geological records, to create reconstructions of the past behaviour of this sector of the East Antarctic Ice Sheet (EAIS), including ice–seafloor interactions. Our data show that an ice stream flowed through Stancomb-Wills Trough and acted as the main conduit for EAIS drainage during the LGM in this sector. Post-LGM ice stream retreat occurred stepwise, with at least three documented grounding-line still-stands, and the trough had become free of grounded ice by ∼10.5 ka cal BP. In contrast, slow-flowing ice once covered the shelf in Brunt Basin and extended westwards toward McDonald Bank. During a later time period, only floating ice was present within Brunt Basin, but large “ice slabs” enclosed within the ice shelf occasionally ran aground at the eastern side of McDonald Bank, forming 10 unusual ramp-shaped seabed features. These ramps are the result of temporary ice shelf grounding events buttressing the ice further upstream. To the west of this area, Halley Trough very likely was free of grounded ice during the LGM, representing a potential refuge for benthic shelf fauna at this time. ISSN:1994-0416 ISSN:1994-0424 |
format |
Article in Journal/Newspaper |
author |
Arndt, Jan Erik Larter, Robert D. Hillenbrand, Claus-Dieter Sørli, Simon H. Forwick, Matthias Smith, James A. Wacker, Lukas |
spellingShingle |
Arndt, Jan Erik Larter, Robert D. Hillenbrand, Claus-Dieter Sørli, Simon H. Forwick, Matthias Smith, James A. Wacker, Lukas Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica |
author_facet |
Arndt, Jan Erik Larter, Robert D. Hillenbrand, Claus-Dieter Sørli, Simon H. Forwick, Matthias Smith, James A. Wacker, Lukas |
author_sort |
Arndt, Jan Erik |
title |
Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica |
title_short |
Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica |
title_full |
Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica |
title_fullStr |
Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica |
title_full_unstemmed |
Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica |
title_sort |
past ice sheet–seabed interactions in the northeastern weddell sea embayment, antarctica |
publisher |
Copernicus |
publishDate |
2020 |
url |
https://hdl.handle.net/20.500.11850/428077 https://doi.org/10.3929/ethz-b-000428077 |
long_lat |
ENVELOPE(-25.000,-25.000,-75.000,-75.000) ENVELOPE(-22.500,-22.500,-74.750,-74.750) ENVELOPE(-26.583,-26.583,-75.500,-75.500) |
geographic |
Antarctic Brunt Basin Brunt Ice Shelf East Antarctic Ice Sheet Mcdonald Bank The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Brunt Basin Brunt Ice Shelf East Antarctic Ice Sheet Mcdonald Bank The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Antarctica Brunt Ice Shelf Ice Sheet Ice Shelf The Cryosphere Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Brunt Ice Shelf Ice Sheet Ice Shelf The Cryosphere Weddell Sea |
op_source |
The Cryosphere, 14 (6) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-14-2115-2020 info:eu-repo/semantics/altIdentifier/wos/000545958000002 http://hdl.handle.net/20.500.11850/428077 doi:10.3929/ethz-b-000428077 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/20.500.11850/428077 https://doi.org/10.3929/ethz-b-000428077 https://doi.org/10.5194/tc-14-2115-2020 |
_version_ |
1766272074463051776 |