Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica
Widespread existing geological records from above the modern ice sheet surface and outboard of the current ice margin show that the Antarctic Ice Sheet (AIS) was much more extensive at the Last Glacial Maximum ( ∼ 20 ka ) than at present. However, whether it was ever smaller than present during the...
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Online Access: | https://doi.org/10.5194/tc-16-1543-2022 https://tc.copernicus.org/articles/16/1543/2022/ |
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ftcopernicus:oai:publications.copernicus.org:tc99287 2023-05-15T14:02:18+02:00 Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica Johnson, Joanne S. Venturelli, Ryan A. Balco, Greg Allen, Claire S. Braddock, Scott Campbell, Seth Goehring, Brent M. Hall, Brenda L. Neff, Peter D. Nichols, Keir A. Rood, Dylan H. Thomas, Elizabeth R. Woodward, John 2022-05-03 application/pdf https://doi.org/10.5194/tc-16-1543-2022 https://tc.copernicus.org/articles/16/1543/2022/ eng eng doi:10.5194/tc-16-1543-2022 https://tc.copernicus.org/articles/16/1543/2022/ eISSN: 1994-0424 Text 2022 ftcopernicus https://doi.org/10.5194/tc-16-1543-2022 2022-05-09T16:22:28Z Widespread existing geological records from above the modern ice sheet surface and outboard of the current ice margin show that the Antarctic Ice Sheet (AIS) was much more extensive at the Last Glacial Maximum ( ∼ 20 ka ) than at present. However, whether it was ever smaller than present during the last few millennia, and (if so) by how much, is known only for a few locations because direct evidence lies within or beneath the ice sheet, which is challenging to access. Here, we describe how retreat and readvance (henceforth “readvance”) of AIS grounding lines during the Holocene could be detected and quantified using subglacial bedrock, subglacial sediments, marine sediment cores, relative sea-level (RSL) records, geodetic observations, radar data, and ice cores. Of these, only subglacial bedrock and subglacial sediments can provide direct evidence for readvance. Marine archives are of limited utility because readvance commonly covers evidence of earlier retreat. Nevertheless, stratigraphic transitions documenting change in environment may provide support for direct evidence from subglacial records, as can the presence of transgressions in RSL records, and isostatic subsidence. With independent age control, ice structure revealed by radar can be used to infer past changes in ice flow and geometry, and therefore potential readvance. Since ice cores capture changes in surface mass balance, elevation, and atmospheric and oceanic circulation that are known to drive grounding line migration, they also have potential for identifying readvance. A multidisciplinary approach is likely to provide the strongest evidence for or against a smaller-than-present AIS in the Holocene. Text Antarc* Antarctic Antarctica Ice Sheet Copernicus Publications: E-Journals Antarctic The Antarctic The Cryosphere 16 5 1543 1562 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Widespread existing geological records from above the modern ice sheet surface and outboard of the current ice margin show that the Antarctic Ice Sheet (AIS) was much more extensive at the Last Glacial Maximum ( ∼ 20 ka ) than at present. However, whether it was ever smaller than present during the last few millennia, and (if so) by how much, is known only for a few locations because direct evidence lies within or beneath the ice sheet, which is challenging to access. Here, we describe how retreat and readvance (henceforth “readvance”) of AIS grounding lines during the Holocene could be detected and quantified using subglacial bedrock, subglacial sediments, marine sediment cores, relative sea-level (RSL) records, geodetic observations, radar data, and ice cores. Of these, only subglacial bedrock and subglacial sediments can provide direct evidence for readvance. Marine archives are of limited utility because readvance commonly covers evidence of earlier retreat. Nevertheless, stratigraphic transitions documenting change in environment may provide support for direct evidence from subglacial records, as can the presence of transgressions in RSL records, and isostatic subsidence. With independent age control, ice structure revealed by radar can be used to infer past changes in ice flow and geometry, and therefore potential readvance. Since ice cores capture changes in surface mass balance, elevation, and atmospheric and oceanic circulation that are known to drive grounding line migration, they also have potential for identifying readvance. A multidisciplinary approach is likely to provide the strongest evidence for or against a smaller-than-present AIS in the Holocene. |
format |
Text |
author |
Johnson, Joanne S. Venturelli, Ryan A. Balco, Greg Allen, Claire S. Braddock, Scott Campbell, Seth Goehring, Brent M. Hall, Brenda L. Neff, Peter D. Nichols, Keir A. Rood, Dylan H. Thomas, Elizabeth R. Woodward, John |
spellingShingle |
Johnson, Joanne S. Venturelli, Ryan A. Balco, Greg Allen, Claire S. Braddock, Scott Campbell, Seth Goehring, Brent M. Hall, Brenda L. Neff, Peter D. Nichols, Keir A. Rood, Dylan H. Thomas, Elizabeth R. Woodward, John Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica |
author_facet |
Johnson, Joanne S. Venturelli, Ryan A. Balco, Greg Allen, Claire S. Braddock, Scott Campbell, Seth Goehring, Brent M. Hall, Brenda L. Neff, Peter D. Nichols, Keir A. Rood, Dylan H. Thomas, Elizabeth R. Woodward, John |
author_sort |
Johnson, Joanne S. |
title |
Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica |
title_short |
Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica |
title_full |
Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica |
title_fullStr |
Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica |
title_full_unstemmed |
Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica |
title_sort |
review article: existing and potential evidence for holocene grounding line retreat and readvance in antarctica |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-1543-2022 https://tc.copernicus.org/articles/16/1543/2022/ |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-16-1543-2022 https://tc.copernicus.org/articles/16/1543/2022/ |
op_doi |
https://doi.org/10.5194/tc-16-1543-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
5 |
container_start_page |
1543 |
op_container_end_page |
1562 |
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1766272497745920000 |