Reconstruction of Changes in the Amundsen Sea and Bellingshausen Sea Sector of the West Antarctic Ice Sheet since the Last Glacial Maximum
Marine and terrestrial geological and marine geophysical data that constrain deglaciation since the Last Glacial Maximum (LGM) of the sector of the West Antarctic Ice Sheet (WAIS) draining into the Amundsen Sea and Bellingshausen Sea have been collated and used as the basis for a set of time-slice r...
Published in: | Quaternary Science Reviews |
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Main Authors: | , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
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Digital Commons @ University of South Florida
2014
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Subjects: | |
Online Access: | https://digitalcommons.usf.edu/msc_facpub/1552 https://doi.org/10.1016/j.quascirev.2013.10.016 |
id |
ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-2558 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
Ice sheet Last Glacial Maximum Holocene Ice stream Grounding line Radiocarbon Cosmogenic isotope Surface exposure age Multibeam swath bathymetry Sediment Glacimarine Diamicton Continental shelf Circumpolar deep water Subglacial meltwater Sea level Life Sciences |
spellingShingle |
Ice sheet Last Glacial Maximum Holocene Ice stream Grounding line Radiocarbon Cosmogenic isotope Surface exposure age Multibeam swath bathymetry Sediment Glacimarine Diamicton Continental shelf Circumpolar deep water Subglacial meltwater Sea level Life Sciences Larter, Robert D. Anderson, John B. Graham, Alastair G. C. Gohl, Karsten Hillenbrand, Claus-Dieter Jakobsson, Martin Johnson, Joanne S. Kuhn, Gerhard Nitsche, Frank O. Smith, James A. Witus, Alexandra E. Bentley, Michael J. Dowdeswell, Julian A. Ehrmann, Werner Klages, Johann P. Lindow, Julia Cofaigh, Colm Ó. Spiegel, Cornelia Reconstruction of Changes in the Amundsen Sea and Bellingshausen Sea Sector of the West Antarctic Ice Sheet since the Last Glacial Maximum |
topic_facet |
Ice sheet Last Glacial Maximum Holocene Ice stream Grounding line Radiocarbon Cosmogenic isotope Surface exposure age Multibeam swath bathymetry Sediment Glacimarine Diamicton Continental shelf Circumpolar deep water Subglacial meltwater Sea level Life Sciences |
description |
Marine and terrestrial geological and marine geophysical data that constrain deglaciation since the Last Glacial Maximum (LGM) of the sector of the West Antarctic Ice Sheet (WAIS) draining into the Amundsen Sea and Bellingshausen Sea have been collated and used as the basis for a set of time-slice reconstructions. The drainage basins in these sectors constitute a little more than one-quarter of the area of the WAIS, but account for about one-third of its surface accumulation. Their mass balance is becoming increasingly negative, and therefore they account for an even larger fraction of current WAIS discharge. If all of the ice in these sectors of the WAIS were discharged to the ocean, global sea level would rise by ca 2 m. There is compelling evidence that grounding lines of palaeo-ice streams were at, or close to, the continental shelf edge along the Amundsen Sea and Bellingshausen Sea margins during the last glacial period. However, the few cosmogenic surface exposure ages and ice core data available from the interior of West Antarctica indicate that ice surface elevations there have changed little since the LGM. In the few areas from which cosmogenic surface exposure ages have been determined near the margin of the ice sheet, they generally suggest that there has been a gradual decrease in ice surface elevation since pre-Holocene times. Radiocarbon dates from glacimarine and the earliest seasonally open marine sediments in continental shelf cores that have been interpreted as providing approximate ages for post-LGM grounding-line retreat indicate different trajectories of palaeo-ice stream recession in the Amundsen Sea and Bellingshausen Sea embayments. The areas were probably subject to similar oceanic, atmospheric and eustatic forcing, in which case the differences are probably largely a consequence of how topographic and geological factors have affected ice flow, and of topographic influences on snow accumulation and warm water inflow across the continental shelf. Pauses in ice retreat are recorded where there are “bottle necks” in cross-shelf troughs in both embayments. The highest retreat rates presently constrained by radiocarbon dates from sediment cores are found where the grounding line retreated across deep basins on the inner shelf in the Amundsen Sea, which is consistent with the marine ice sheet instability hypothesis. Deglacial ages from the Amundsen Sea Embayment (ASE) and Eltanin Bay (southern Bellingshausen Sea) indicate that the ice sheet had already retreated close to its modern limits by early Holocene time, which suggests that the rapid ice thinning, flow acceleration, and grounding line retreat observed in this sector over recent decades are unusual in the context of the past 10,000 years. |
format |
Article in Journal/Newspaper |
author |
Larter, Robert D. Anderson, John B. Graham, Alastair G. C. Gohl, Karsten Hillenbrand, Claus-Dieter Jakobsson, Martin Johnson, Joanne S. Kuhn, Gerhard Nitsche, Frank O. Smith, James A. Witus, Alexandra E. Bentley, Michael J. Dowdeswell, Julian A. Ehrmann, Werner Klages, Johann P. Lindow, Julia Cofaigh, Colm Ó. Spiegel, Cornelia |
author_facet |
Larter, Robert D. Anderson, John B. Graham, Alastair G. C. Gohl, Karsten Hillenbrand, Claus-Dieter Jakobsson, Martin Johnson, Joanne S. Kuhn, Gerhard Nitsche, Frank O. Smith, James A. Witus, Alexandra E. Bentley, Michael J. Dowdeswell, Julian A. Ehrmann, Werner Klages, Johann P. Lindow, Julia Cofaigh, Colm Ó. Spiegel, Cornelia |
author_sort |
Larter, Robert D. |
title |
Reconstruction of Changes in the Amundsen Sea and Bellingshausen Sea Sector of the West Antarctic Ice Sheet since the Last Glacial Maximum |
title_short |
Reconstruction of Changes in the Amundsen Sea and Bellingshausen Sea Sector of the West Antarctic Ice Sheet since the Last Glacial Maximum |
title_full |
Reconstruction of Changes in the Amundsen Sea and Bellingshausen Sea Sector of the West Antarctic Ice Sheet since the Last Glacial Maximum |
title_fullStr |
Reconstruction of Changes in the Amundsen Sea and Bellingshausen Sea Sector of the West Antarctic Ice Sheet since the Last Glacial Maximum |
title_full_unstemmed |
Reconstruction of Changes in the Amundsen Sea and Bellingshausen Sea Sector of the West Antarctic Ice Sheet since the Last Glacial Maximum |
title_sort |
reconstruction of changes in the amundsen sea and bellingshausen sea sector of the west antarctic ice sheet since the last glacial maximum |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2014 |
url |
https://digitalcommons.usf.edu/msc_facpub/1552 https://doi.org/10.1016/j.quascirev.2013.10.016 |
long_lat |
ENVELOPE(-82.000,-82.000,-73.667,-73.667) |
geographic |
Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet Bellingshausen Sea Eltanin Bay |
geographic_facet |
Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet Bellingshausen Sea Eltanin Bay |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Bellingshausen Sea ice core Ice Sheet West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Bellingshausen Sea ice core Ice Sheet West Antarctica |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1552 https://doi.org/10.1016/j.quascirev.2013.10.016 |
op_doi |
https://doi.org/10.1016/j.quascirev.2013.10.016 |
container_title |
Quaternary Science Reviews |
container_volume |
100 |
container_start_page |
55 |
op_container_end_page |
86 |
_version_ |
1766374011062714368 |
spelling |
ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-2558 2023-05-15T13:23:40+02:00 Reconstruction of Changes in the Amundsen Sea and Bellingshausen Sea Sector of the West Antarctic Ice Sheet since the Last Glacial Maximum Larter, Robert D. Anderson, John B. Graham, Alastair G. C. Gohl, Karsten Hillenbrand, Claus-Dieter Jakobsson, Martin Johnson, Joanne S. Kuhn, Gerhard Nitsche, Frank O. Smith, James A. Witus, Alexandra E. Bentley, Michael J. Dowdeswell, Julian A. Ehrmann, Werner Klages, Johann P. Lindow, Julia Cofaigh, Colm Ó. Spiegel, Cornelia 2014-01-01T08:00:00Z https://digitalcommons.usf.edu/msc_facpub/1552 https://doi.org/10.1016/j.quascirev.2013.10.016 unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1552 https://doi.org/10.1016/j.quascirev.2013.10.016 Marine Science Faculty Publications Ice sheet Last Glacial Maximum Holocene Ice stream Grounding line Radiocarbon Cosmogenic isotope Surface exposure age Multibeam swath bathymetry Sediment Glacimarine Diamicton Continental shelf Circumpolar deep water Subglacial meltwater Sea level Life Sciences article 2014 ftunisfloridatam https://doi.org/10.1016/j.quascirev.2013.10.016 2022-01-20T18:39:53Z Marine and terrestrial geological and marine geophysical data that constrain deglaciation since the Last Glacial Maximum (LGM) of the sector of the West Antarctic Ice Sheet (WAIS) draining into the Amundsen Sea and Bellingshausen Sea have been collated and used as the basis for a set of time-slice reconstructions. The drainage basins in these sectors constitute a little more than one-quarter of the area of the WAIS, but account for about one-third of its surface accumulation. Their mass balance is becoming increasingly negative, and therefore they account for an even larger fraction of current WAIS discharge. If all of the ice in these sectors of the WAIS were discharged to the ocean, global sea level would rise by ca 2 m. There is compelling evidence that grounding lines of palaeo-ice streams were at, or close to, the continental shelf edge along the Amundsen Sea and Bellingshausen Sea margins during the last glacial period. However, the few cosmogenic surface exposure ages and ice core data available from the interior of West Antarctica indicate that ice surface elevations there have changed little since the LGM. In the few areas from which cosmogenic surface exposure ages have been determined near the margin of the ice sheet, they generally suggest that there has been a gradual decrease in ice surface elevation since pre-Holocene times. Radiocarbon dates from glacimarine and the earliest seasonally open marine sediments in continental shelf cores that have been interpreted as providing approximate ages for post-LGM grounding-line retreat indicate different trajectories of palaeo-ice stream recession in the Amundsen Sea and Bellingshausen Sea embayments. The areas were probably subject to similar oceanic, atmospheric and eustatic forcing, in which case the differences are probably largely a consequence of how topographic and geological factors have affected ice flow, and of topographic influences on snow accumulation and warm water inflow across the continental shelf. Pauses in ice retreat are recorded where there are “bottle necks” in cross-shelf troughs in both embayments. The highest retreat rates presently constrained by radiocarbon dates from sediment cores are found where the grounding line retreated across deep basins on the inner shelf in the Amundsen Sea, which is consistent with the marine ice sheet instability hypothesis. Deglacial ages from the Amundsen Sea Embayment (ASE) and Eltanin Bay (southern Bellingshausen Sea) indicate that the ice sheet had already retreated close to its modern limits by early Holocene time, which suggests that the rapid ice thinning, flow acceleration, and grounding line retreat observed in this sector over recent decades are unusual in the context of the past 10,000 years. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Bellingshausen Sea ice core Ice Sheet West Antarctica Digital Commons University of South Florida (USF) Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet Bellingshausen Sea Eltanin Bay ENVELOPE(-82.000,-82.000,-73.667,-73.667) Quaternary Science Reviews 100 55 86 |