New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum
Glaciers flowing into the Amundsen Sea Embayment (ASE) account for >35% of the total discharge of the West Antarctic Ice Sheet (WAIS) and have thinned and retreated dramatically over the past two decades. Here we present detailed marine geological data and an extensive new radiocarbon dataset fro...
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Online Access: | https://epic.awi.de/id/eprint/36138/ http://www.sciencedirect.com/science/article/pii/S0921818114001489 https://hdl.handle.net/10013/epic.44397 |
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ftawi:oai:epic.awi.de:36138 2023-05-15T13:23:57+02:00 New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum Smith, James A. Hillenbrand, Claus-Dieter Kuhn, Gerhard Klages, Johann Phillip Graham, Alastair G.C. Larter, Robert D. Ehrmann, Werner Moreton, Steven G. Wiers, Steffen Frederichs, Thomas 2014-11 https://epic.awi.de/id/eprint/36138/ http://www.sciencedirect.com/science/article/pii/S0921818114001489 https://hdl.handle.net/10013/epic.44397 unknown Elsevier Smith, J. A. , Hillenbrand, C. D. , Kuhn, G. orcid:0000-0001-6069-7485 , Klages, J. P. orcid:0000-0003-0968-1183 , Graham, A. G. , Larter, R. D. , Ehrmann, W. , Moreton, S. G. , Wiers, S. and Frederichs, T. (2014) New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum , Global and Planetary Change, 122 , pp. 224-237 . doi:10.1016/j.gloplacha.2014.07.015 <https://doi.org/10.1016/j.gloplacha.2014.07.015> , hdl:10013/epic.44397 EPIC3Global and Planetary Change, Elsevier, 122, pp. 224-237, ISSN: 0921-8181 Article isiRev 2014 ftawi https://doi.org/10.1016/j.gloplacha.2014.07.015 2021-12-24T15:39:46Z Glaciers flowing into the Amundsen Sea Embayment (ASE) account for >35% of the total discharge of the West Antarctic Ice Sheet (WAIS) and have thinned and retreated dramatically over the past two decades. Here we present detailed marine geological data and an extensive new radiocarbon dataset from the eastern ASE in order to constrain the retreat of the WAIS since the Last Glacial Maximum (LGM) and assess the significance of these recent changes. Our dating approach, relying mainly on the acid insoluble organic (AIO) fraction, utilises multi-proxy analyses of the sediments to characterise their lithofacies and determine the horizon in each core that would yield the most reliable age for deglaciation. In total, we dated 69 samples and show that deglaciation of the outer shelf was underway before 20,600 calibrated years before present (cal. yr BP), reaching the mid-shelf by 13,575 cal. yr BP and the inner shelf to within c.150 km of the present grounding line by 10,615 cal. yr BP. The timing of retreat is broadly consistent with previously published radiocarbon dates on biogenic carbonate from the eastern ASE as well as AIO 14C ages from the western ASE and provides new constraints for ice sheet models. The overall retreat trajectory – slow on the outer shelf, more rapid from the middle to inner shelf – clearly highlights the importance of reverse bedslopes in controlling phases of accelerated groundling line retreat. Despite revealing these broad scale trends, the current dataset does not capture detailed changes in ice flow, such as stillstands during grounding line retreat (i.e., deposition of grounding zone wedges) and possible readvances as depicted in the geomorphological record. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Ice Sheet Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Amundsen Sea Antarctic West Antarctic Ice Sheet Global and Planetary Change 122 224 237 |
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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 |
Glaciers flowing into the Amundsen Sea Embayment (ASE) account for >35% of the total discharge of the West Antarctic Ice Sheet (WAIS) and have thinned and retreated dramatically over the past two decades. Here we present detailed marine geological data and an extensive new radiocarbon dataset from the eastern ASE in order to constrain the retreat of the WAIS since the Last Glacial Maximum (LGM) and assess the significance of these recent changes. Our dating approach, relying mainly on the acid insoluble organic (AIO) fraction, utilises multi-proxy analyses of the sediments to characterise their lithofacies and determine the horizon in each core that would yield the most reliable age for deglaciation. In total, we dated 69 samples and show that deglaciation of the outer shelf was underway before 20,600 calibrated years before present (cal. yr BP), reaching the mid-shelf by 13,575 cal. yr BP and the inner shelf to within c.150 km of the present grounding line by 10,615 cal. yr BP. The timing of retreat is broadly consistent with previously published radiocarbon dates on biogenic carbonate from the eastern ASE as well as AIO 14C ages from the western ASE and provides new constraints for ice sheet models. The overall retreat trajectory – slow on the outer shelf, more rapid from the middle to inner shelf – clearly highlights the importance of reverse bedslopes in controlling phases of accelerated groundling line retreat. Despite revealing these broad scale trends, the current dataset does not capture detailed changes in ice flow, such as stillstands during grounding line retreat (i.e., deposition of grounding zone wedges) and possible readvances as depicted in the geomorphological record. |
format |
Article in Journal/Newspaper |
author |
Smith, James A. Hillenbrand, Claus-Dieter Kuhn, Gerhard Klages, Johann Phillip Graham, Alastair G.C. Larter, Robert D. Ehrmann, Werner Moreton, Steven G. Wiers, Steffen Frederichs, Thomas |
spellingShingle |
Smith, James A. Hillenbrand, Claus-Dieter Kuhn, Gerhard Klages, Johann Phillip Graham, Alastair G.C. Larter, Robert D. Ehrmann, Werner Moreton, Steven G. Wiers, Steffen Frederichs, Thomas New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum |
author_facet |
Smith, James A. Hillenbrand, Claus-Dieter Kuhn, Gerhard Klages, Johann Phillip Graham, Alastair G.C. Larter, Robert D. Ehrmann, Werner Moreton, Steven G. Wiers, Steffen Frederichs, Thomas |
author_sort |
Smith, James A. |
title |
New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum |
title_short |
New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum |
title_full |
New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum |
title_fullStr |
New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum |
title_full_unstemmed |
New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum |
title_sort |
new constraints on the timing of west antarctic ice sheet retreat in the eastern amundsen sea since the last glacial maximum |
publisher |
Elsevier |
publishDate |
2014 |
url |
https://epic.awi.de/id/eprint/36138/ http://www.sciencedirect.com/science/article/pii/S0921818114001489 https://hdl.handle.net/10013/epic.44397 |
geographic |
Amundsen Sea Antarctic West Antarctic Ice Sheet |
geographic_facet |
Amundsen Sea Antarctic West Antarctic Ice Sheet |
genre |
Amundsen Sea Antarc* Antarctic Ice Sheet |
genre_facet |
Amundsen Sea Antarc* Antarctic Ice Sheet |
op_source |
EPIC3Global and Planetary Change, Elsevier, 122, pp. 224-237, ISSN: 0921-8181 |
op_relation |
Smith, J. A. , Hillenbrand, C. D. , Kuhn, G. orcid:0000-0001-6069-7485 , Klages, J. P. orcid:0000-0003-0968-1183 , Graham, A. G. , Larter, R. D. , Ehrmann, W. , Moreton, S. G. , Wiers, S. and Frederichs, T. (2014) New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum , Global and Planetary Change, 122 , pp. 224-237 . doi:10.1016/j.gloplacha.2014.07.015 <https://doi.org/10.1016/j.gloplacha.2014.07.015> , hdl:10013/epic.44397 |
op_doi |
https://doi.org/10.1016/j.gloplacha.2014.07.015 |
container_title |
Global and Planetary Change |
container_volume |
122 |
container_start_page |
224 |
op_container_end_page |
237 |
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1766376495291301888 |