New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea
Past ice sheet conditions in the southern Weddell Sea remain poorly known. Previous studies have led to contradicting scenarios of maximum ice extent during the Last Glacial Maximum (LGM). Scenario A is mainly based on terrestrial data indicating limited ice sheet thickening in the hinterland and su...
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ftawi:oai:epic.awi.de:47492 2023-05-15T16:40:11+02:00 New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea Arndt, Jan Erik Hillenbrand, Claus-Dieter Grobe, Hannes Kuhn, Gerhard Wacker, Lukas Larter, Robert D. Dorschel, Boris Sørli, Simon Forwick, Matthias 2018-06-19 https://epic.awi.de/id/eprint/47492/ https://hdl.handle.net/10013/epic.691abfbc-2eec-4990-9576-fb69dd030678 unknown Arndt, J. E. orcid:0000-0002-9413-1612 , Hillenbrand, C. D. , Grobe, H. orcid:0000-0002-4133-2218 , Kuhn, G. orcid:0000-0001-6069-7485 , Wacker, L. , Larter, R. D. , Dorschel, B. orcid:0000-0002-3495-5927 , Sørli, S. and Forwick, M. (2018) New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea , Polar2018, Davos, 18 June 2018 - 23 June 2018 . hdl:10013/epic.691abfbc-2eec-4990-9576-fb69dd030678 EPIC3Polar2018, Davos, 2018-06-18-2018-06-23 Conference notRev 2018 ftawi 2021-12-24T15:43:57Z Past ice sheet conditions in the southern Weddell Sea remain poorly known. Previous studies have led to contradicting scenarios of maximum ice extent during the Last Glacial Maximum (LGM). Scenario A is mainly based on terrestrial data indicating limited ice sheet thickening in the hinterland and suggests a LGM grounding-line position on the inner shelf. Scenario B is based on marine geological/-physical data and concludes that the grounding line was located on the outer shelf (~650 km further offshore than in scenario A). In addition, studies suggest a complex history of ice retreat and drainage pattern since the LGM that needs further constraint. We investigated hydroacoustic data acquired during 17 expeditions. A key finding is a previously unknown stacked grounding zone wedge (GZW) located in Filchner Trough on the outer shelf showing that a palaeo-ice stream stabilized at this position at least twice. Radiocarbon dates from sediment cores indicate that (i) the GZW was formed in the early Holocene and (ii) grounded ice did not extend seaward at the LGM. Hence, the grounding line in Filchner Trough experienced dynamic changes in the Holocene and ice sheet retreat after the LGM was not linear. Ice-flow switches in the hinterland possibly explain this behaviour. Further interesting findings are made in Brunt Basin suggesting the existence of cold-based ice or impacts of large icebergs. In addition, new data will be acquired in the area with RV Polarstern in Jan-Mar 2018. Conference Object Ice Sheet Weddell Sea Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Brunt Basin ENVELOPE(-25.000,-25.000,-75.000,-75.000) Filchner Trough ENVELOPE(-36.000,-36.000,-77.000,-77.000) Weddell Weddell Sea |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Past ice sheet conditions in the southern Weddell Sea remain poorly known. Previous studies have led to contradicting scenarios of maximum ice extent during the Last Glacial Maximum (LGM). Scenario A is mainly based on terrestrial data indicating limited ice sheet thickening in the hinterland and suggests a LGM grounding-line position on the inner shelf. Scenario B is based on marine geological/-physical data and concludes that the grounding line was located on the outer shelf (~650 km further offshore than in scenario A). In addition, studies suggest a complex history of ice retreat and drainage pattern since the LGM that needs further constraint. We investigated hydroacoustic data acquired during 17 expeditions. A key finding is a previously unknown stacked grounding zone wedge (GZW) located in Filchner Trough on the outer shelf showing that a palaeo-ice stream stabilized at this position at least twice. Radiocarbon dates from sediment cores indicate that (i) the GZW was formed in the early Holocene and (ii) grounded ice did not extend seaward at the LGM. Hence, the grounding line in Filchner Trough experienced dynamic changes in the Holocene and ice sheet retreat after the LGM was not linear. Ice-flow switches in the hinterland possibly explain this behaviour. Further interesting findings are made in Brunt Basin suggesting the existence of cold-based ice or impacts of large icebergs. In addition, new data will be acquired in the area with RV Polarstern in Jan-Mar 2018. |
format |
Conference Object |
author |
Arndt, Jan Erik Hillenbrand, Claus-Dieter Grobe, Hannes Kuhn, Gerhard Wacker, Lukas Larter, Robert D. Dorschel, Boris Sørli, Simon Forwick, Matthias |
spellingShingle |
Arndt, Jan Erik Hillenbrand, Claus-Dieter Grobe, Hannes Kuhn, Gerhard Wacker, Lukas Larter, Robert D. Dorschel, Boris Sørli, Simon Forwick, Matthias New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea |
author_facet |
Arndt, Jan Erik Hillenbrand, Claus-Dieter Grobe, Hannes Kuhn, Gerhard Wacker, Lukas Larter, Robert D. Dorschel, Boris Sørli, Simon Forwick, Matthias |
author_sort |
Arndt, Jan Erik |
title |
New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea |
title_short |
New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea |
title_full |
New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea |
title_fullStr |
New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea |
title_full_unstemmed |
New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea |
title_sort |
new constraints on post-lgm ice sheet dynamics in the southern weddell sea |
publishDate |
2018 |
url |
https://epic.awi.de/id/eprint/47492/ https://hdl.handle.net/10013/epic.691abfbc-2eec-4990-9576-fb69dd030678 |
long_lat |
ENVELOPE(-25.000,-25.000,-75.000,-75.000) ENVELOPE(-36.000,-36.000,-77.000,-77.000) |
geographic |
Brunt Basin Filchner Trough Weddell Weddell Sea |
geographic_facet |
Brunt Basin Filchner Trough Weddell Weddell Sea |
genre |
Ice Sheet Weddell Sea |
genre_facet |
Ice Sheet Weddell Sea |
op_source |
EPIC3Polar2018, Davos, 2018-06-18-2018-06-23 |
op_relation |
Arndt, J. E. orcid:0000-0002-9413-1612 , Hillenbrand, C. D. , Grobe, H. orcid:0000-0002-4133-2218 , Kuhn, G. orcid:0000-0001-6069-7485 , Wacker, L. , Larter, R. D. , Dorschel, B. orcid:0000-0002-3495-5927 , Sørli, S. and Forwick, M. (2018) New constraints on post-LGM ice sheet dynamics in the southern Weddell Sea , Polar2018, Davos, 18 June 2018 - 23 June 2018 . hdl:10013/epic.691abfbc-2eec-4990-9576-fb69dd030678 |
_version_ |
1766030568092336128 |