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, cal. ka BP) and its subsequent retreat from the shelf are poorly constrained, with two conflicting scenarios being discussed. Today, the modern Brunt...
Published in: | The Cryosphere |
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2020
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Online Access: | http://nora.nerc.ac.uk/id/eprint/525866/ https://nora.nerc.ac.uk/id/eprint/525866/1/tc-14-2115-2020.pdf https://tc.copernicus.org/articles/14/2115/2020/ |
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ftnerc:oai:nora.nerc.ac.uk:525866 2023-05-15T13:41:44+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 2020-06-30 text http://nora.nerc.ac.uk/id/eprint/525866/ https://nora.nerc.ac.uk/id/eprint/525866/1/tc-14-2115-2020.pdf https://tc.copernicus.org/articles/14/2115/2020/ en eng Copernicus https://nora.nerc.ac.uk/id/eprint/525866/1/tc-14-2115-2020.pdf Arndt, Jan Erik; Larter, Robert D. orcid:0000-0002-8414-7389 Hillenbrand, Claus-Dieter orcid:0000-0003-0240-7317 Sørli, Simon H.; Forwick, Matthias; Smith, James A. orcid:0000-0002-1333-2544 Wacker, Lukas. 2020 Past ice sheet-seabed interactions in the northeastern Weddell Sea Embayment, Antarctica. The Cryosphere, 14 (6). 2115-2135. https://doi.org/10.5194/tc-14-2115-2020 <https://doi.org/10.5194/tc-14-2115-2020> cc_by_4 CC-BY Publication - Article PeerReviewed 2020 ftnerc https://doi.org/10.5194/tc-14-2115-2020 2023-02-04T19:49:39Z The Antarctic Ice Sheet extent in the Weddell Sea Embayment (WSE) during the Last Glacial Maximum (LGM; ca. 19–25 calibrated kiloyears before present, cal. ka 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, for 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. 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 cal. ka 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 ten 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. Article in Journal/Newspaper Antarc* Antarctic Antarctica Brunt Ice Shelf Ice Sheet Ice Shelf The Cryosphere Weddell Sea Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Weddell Sea East Antarctic Ice Sheet Weddell Brunt Ice Shelf ENVELOPE(-22.500,-22.500,-74.750,-74.750) Brunt Basin ENVELOPE(-25.000,-25.000,-75.000,-75.000) Mcdonald Bank ENVELOPE(-26.583,-26.583,-75.500,-75.500) The Cryosphere 14 6 2115 2135 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
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, cal. ka 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, for 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. 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 cal. ka 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 ten 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. |
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 |
http://nora.nerc.ac.uk/id/eprint/525866/ https://nora.nerc.ac.uk/id/eprint/525866/1/tc-14-2115-2020.pdf https://tc.copernicus.org/articles/14/2115/2020/ |
long_lat |
ENVELOPE(-22.500,-22.500,-74.750,-74.750) ENVELOPE(-25.000,-25.000,-75.000,-75.000) ENVELOPE(-26.583,-26.583,-75.500,-75.500) |
geographic |
Antarctic The Antarctic Weddell Sea East Antarctic Ice Sheet Weddell Brunt Ice Shelf Brunt Basin Mcdonald Bank |
geographic_facet |
Antarctic The Antarctic Weddell Sea East Antarctic Ice Sheet Weddell Brunt Ice Shelf Brunt Basin Mcdonald Bank |
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_relation |
https://nora.nerc.ac.uk/id/eprint/525866/1/tc-14-2115-2020.pdf Arndt, Jan Erik; Larter, Robert D. orcid:0000-0002-8414-7389 Hillenbrand, Claus-Dieter orcid:0000-0003-0240-7317 Sørli, Simon H.; Forwick, Matthias; Smith, James A. orcid:0000-0002-1333-2544 Wacker, Lukas. 2020 Past ice sheet-seabed interactions in the northeastern Weddell Sea Embayment, Antarctica. The Cryosphere, 14 (6). 2115-2135. https://doi.org/10.5194/tc-14-2115-2020 <https://doi.org/10.5194/tc-14-2115-2020> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-14-2115-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
6 |
container_start_page |
2115 |
op_container_end_page |
2135 |
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1766156214457073664 |