Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) - new evidence from Rauer Group
Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holoc...
Main Authors: | , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Research Online
2016
|
Subjects: | |
Online Access: | https://ro.uow.edu.au/smhpapers/4258 https://ro.uow.edu.au/cgi/viewcontent.cgi?article=5282&context=smhpapers |
id |
ftunivwollongong:oai:ro.uow.edu.au:smhpapers-5282 |
---|---|
record_format |
openpolar |
spelling |
ftunivwollongong:oai:ro.uow.edu.au:smhpapers-5282 2023-05-15T13:58:42+02:00 Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) - new evidence from Rauer Group Berg, Sonja White, Duanne A Bennike, Ole Fulop, Reka H Fink, David Wagner, Bernd Melles, Martin 2016-01-01T08:00:00Z application/pdf https://ro.uow.edu.au/smhpapers/4258 https://ro.uow.edu.au/cgi/viewcontent.cgi?article=5282&context=smhpapers unknown Research Online https://ro.uow.edu.au/smhpapers/4258 https://ro.uow.edu.au/cgi/viewcontent.cgi?article=5282&context=smhpapers Faculty of Science, Medicine and Health - Papers: part A Medicine and Health Sciences Social and Behavioral Sciences article 2016 ftunivwollongong 2020-02-25T11:35:03Z Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ice Sheet Prydz Bay University of Wollongong, Australia: Research Online Antarctic East Antarctic Ice Sheet East Antarctica New Lake ENVELOPE(-109.468,-109.468,62.684,62.684) Prydz Bay Rauer Group ENVELOPE(77.833,77.833,-68.850,-68.850) |
institution |
Open Polar |
collection |
University of Wollongong, Australia: Research Online |
op_collection_id |
ftunivwollongong |
language |
unknown |
topic |
Medicine and Health Sciences Social and Behavioral Sciences |
spellingShingle |
Medicine and Health Sciences Social and Behavioral Sciences Berg, Sonja White, Duanne A Bennike, Ole Fulop, Reka H Fink, David Wagner, Bernd Melles, Martin Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) - new evidence from Rauer Group |
topic_facet |
Medicine and Health Sciences Social and Behavioral Sciences |
description |
Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records. |
format |
Article in Journal/Newspaper |
author |
Berg, Sonja White, Duanne A Bennike, Ole Fulop, Reka H Fink, David Wagner, Bernd Melles, Martin |
author_facet |
Berg, Sonja White, Duanne A Bennike, Ole Fulop, Reka H Fink, David Wagner, Bernd Melles, Martin |
author_sort |
Berg, Sonja |
title |
Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) - new evidence from Rauer Group |
title_short |
Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) - new evidence from Rauer Group |
title_full |
Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) - new evidence from Rauer Group |
title_fullStr |
Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) - new evidence from Rauer Group |
title_full_unstemmed |
Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) - new evidence from Rauer Group |
title_sort |
unglaciated areas in east antarctica during the last glacial (marine isotope stage 3) - new evidence from rauer group |
publisher |
Research Online |
publishDate |
2016 |
url |
https://ro.uow.edu.au/smhpapers/4258 https://ro.uow.edu.au/cgi/viewcontent.cgi?article=5282&context=smhpapers |
long_lat |
ENVELOPE(-109.468,-109.468,62.684,62.684) ENVELOPE(77.833,77.833,-68.850,-68.850) |
geographic |
Antarctic East Antarctic Ice Sheet East Antarctica New Lake Prydz Bay Rauer Group |
geographic_facet |
Antarctic East Antarctic Ice Sheet East Antarctica New Lake Prydz Bay Rauer Group |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Prydz Bay |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Prydz Bay |
op_source |
Faculty of Science, Medicine and Health - Papers: part A |
op_relation |
https://ro.uow.edu.au/smhpapers/4258 https://ro.uow.edu.au/cgi/viewcontent.cgi?article=5282&context=smhpapers |
_version_ |
1766267052907036672 |