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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COPERNICUS GESELLSCHAFT MBH
2020
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Online Access: | https://epic.awi.de/id/eprint/53417/ https://epic.awi.de/id/eprint/53417/1/tc-14-2115-2020.pdf https://doi.org/10.5194/tc-14-2115-2020 https://hdl.handle.net/10013/epic.50adb661-e2fd-4290-ac3d-ac641bb9cdf8 https://hdl.handle.net/ |
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ftawi:oai:epic.awi.de:53417 2023-05-15T13:45:22+02:00 Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica Arndt, Jan Erik Larter, R. D. Hillenbrand, C. D. Sørli, S. H. Forwick, Matthias Smith, J. A. Wacker, Lukas 2020-06-30 application/pdf https://epic.awi.de/id/eprint/53417/ https://epic.awi.de/id/eprint/53417/1/tc-14-2115-2020.pdf https://doi.org/10.5194/tc-14-2115-2020 https://hdl.handle.net/10013/epic.50adb661-e2fd-4290-ac3d-ac641bb9cdf8 https://hdl.handle.net/ unknown COPERNICUS GESELLSCHAFT MBH https://epic.awi.de/id/eprint/53417/1/tc-14-2115-2020.pdf https://hdl.handle.net/ Arndt, J. E. orcid:0000-0002-9413-1612 , Larter, R. D. , Hillenbrand, C. D. , Sørli, S. H. , Forwick, M. , Smith, J. A. and Wacker, L. (2020) Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica , Cryosphere, 14 , pp. 2115-2135 . doi:10.5194/tc-14-2115-2020 <https://doi.org/10.5194/tc-14-2115-2020> , hdl:10013/epic.50adb661-e2fd-4290-ac3d-ac641bb9cdf8 EPIC3Cryosphere, COPERNICUS GESELLSCHAFT MBH, 14, pp. 2115-2135, ISSN: 1994-0416 Article isiRev 2020 ftawi https://doi.org/10.5194/tc-14-2115-2020 2021-12-24T15:46:04Z 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 Weddell Sea Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) 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 |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
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, R. D. Hillenbrand, C. D. Sørli, S. H. Forwick, Matthias Smith, J. A. Wacker, Lukas |
spellingShingle |
Arndt, Jan Erik Larter, R. D. Hillenbrand, C. D. Sørli, S. H. Forwick, Matthias Smith, J. A. Wacker, Lukas Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica |
author_facet |
Arndt, Jan Erik Larter, R. D. Hillenbrand, C. D. Sørli, S. H. Forwick, Matthias Smith, J. 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 GESELLSCHAFT MBH |
publishDate |
2020 |
url |
https://epic.awi.de/id/eprint/53417/ https://epic.awi.de/id/eprint/53417/1/tc-14-2115-2020.pdf https://doi.org/10.5194/tc-14-2115-2020 https://hdl.handle.net/10013/epic.50adb661-e2fd-4290-ac3d-ac641bb9cdf8 https://hdl.handle.net/ |
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 Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Brunt Ice Shelf Ice Sheet Ice Shelf Weddell Sea |
op_source |
EPIC3Cryosphere, COPERNICUS GESELLSCHAFT MBH, 14, pp. 2115-2135, ISSN: 1994-0416 |
op_relation |
https://epic.awi.de/id/eprint/53417/1/tc-14-2115-2020.pdf https://hdl.handle.net/ Arndt, J. E. orcid:0000-0002-9413-1612 , Larter, R. D. , Hillenbrand, C. D. , Sørli, S. H. , Forwick, M. , Smith, J. A. and Wacker, L. (2020) Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica , Cryosphere, 14 , pp. 2115-2135 . doi:10.5194/tc-14-2115-2020 <https://doi.org/10.5194/tc-14-2115-2020> , hdl:10013/epic.50adb661-e2fd-4290-ac3d-ac641bb9cdf8 |
op_doi |
https://doi.org/10.5194/tc-14-2115-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
6 |
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2115 |
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2135 |
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