Age determination for sediment cores from the Amundsen Sea Embayment
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 fr...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.835462 2023-05-15T13:23:59+02:00 Age determination for sediment cores from the Amundsen Sea Embayment Smith, James A Hillenbrand, Claus-Dieter Kuhn, Gerhard Klages, Johann Philipp Graham, Alastair G C Larter, Robert D Ehrmann, Werner Moreton, Steven Grahame Wiers, Steffen Frederichs, Thomas MEDIAN LATITUDE: -72.920947 * MEDIAN LONGITUDE: -105.387368 * SOUTH-BOUND LATITUDE: -74.682500 * WEST-BOUND LONGITUDE: -117.843000 * NORTH-BOUND LATITUDE: -71.067800 * EAST-BOUND LONGITUDE: -102.621300 * DATE/TIME START: 2006-02-08T23:59:00 * DATE/TIME END: 2010-03-20T08:42:00 2014-09-02 application/zip, 30 datasets https://doi.pangaea.de/10.1594/PANGAEA.835462 https://doi.org/10.1594/PANGAEA.835462 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.835462 https://doi.org/10.1594/PANGAEA.835462 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Smith, James A; Hillenbrand, Claus-Dieter; Kuhn, Gerhard; Klages, Johann Philipp; Graham, Alastair G C; Larter, Robert D; Ehrmann, Werner; Moreton, Steven Grahame; Wiers, Steffen; Frederichs, Thomas (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, 224-237, https://doi.org/10.1016/j.gloplacha.2014.07.015 Dataset 2014 ftpangaea https://doi.org/10.1594/PANGAEA.835462 https://doi.org/10.1016/j.gloplacha.2014.07.015 2023-01-20T07:33:20Z 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. Dataset Amundsen Sea Antarc* Antarctic Ice Sheet PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Amundsen Sea West Antarctic Ice Sheet ENVELOPE(-117.843000,-102.621300,-71.067800,-74.682500) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
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 |
Dataset |
author |
Smith, James A Hillenbrand, Claus-Dieter Kuhn, Gerhard Klages, Johann Philipp Graham, Alastair G C Larter, Robert D Ehrmann, Werner Moreton, Steven Grahame Wiers, Steffen Frederichs, Thomas |
spellingShingle |
Smith, James A Hillenbrand, Claus-Dieter Kuhn, Gerhard Klages, Johann Philipp Graham, Alastair G C Larter, Robert D Ehrmann, Werner Moreton, Steven Grahame Wiers, Steffen Frederichs, Thomas Age determination for sediment cores from the Amundsen Sea Embayment |
author_facet |
Smith, James A Hillenbrand, Claus-Dieter Kuhn, Gerhard Klages, Johann Philipp Graham, Alastair G C Larter, Robert D Ehrmann, Werner Moreton, Steven Grahame Wiers, Steffen Frederichs, Thomas |
author_sort |
Smith, James A |
title |
Age determination for sediment cores from the Amundsen Sea Embayment |
title_short |
Age determination for sediment cores from the Amundsen Sea Embayment |
title_full |
Age determination for sediment cores from the Amundsen Sea Embayment |
title_fullStr |
Age determination for sediment cores from the Amundsen Sea Embayment |
title_full_unstemmed |
Age determination for sediment cores from the Amundsen Sea Embayment |
title_sort |
age determination for sediment cores from the amundsen sea embayment |
publisher |
PANGAEA |
publishDate |
2014 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.835462 https://doi.org/10.1594/PANGAEA.835462 |
op_coverage |
MEDIAN LATITUDE: -72.920947 * MEDIAN LONGITUDE: -105.387368 * SOUTH-BOUND LATITUDE: -74.682500 * WEST-BOUND LONGITUDE: -117.843000 * NORTH-BOUND LATITUDE: -71.067800 * EAST-BOUND LONGITUDE: -102.621300 * DATE/TIME START: 2006-02-08T23:59:00 * DATE/TIME END: 2010-03-20T08:42:00 |
long_lat |
ENVELOPE(-117.843000,-102.621300,-71.067800,-74.682500) |
geographic |
Antarctic Amundsen Sea West Antarctic Ice Sheet |
geographic_facet |
Antarctic Amundsen Sea West Antarctic Ice Sheet |
genre |
Amundsen Sea Antarc* Antarctic Ice Sheet |
genre_facet |
Amundsen Sea Antarc* Antarctic Ice Sheet |
op_source |
Supplement to: Smith, James A; Hillenbrand, Claus-Dieter; Kuhn, Gerhard; Klages, Johann Philipp; Graham, Alastair G C; Larter, Robert D; Ehrmann, Werner; Moreton, Steven Grahame; Wiers, Steffen; Frederichs, Thomas (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, 224-237, https://doi.org/10.1016/j.gloplacha.2014.07.015 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.835462 https://doi.org/10.1594/PANGAEA.835462 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.835462 https://doi.org/10.1016/j.gloplacha.2014.07.015 |
_version_ |
1766376721218535424 |