Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments
Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediment...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/559377 2023-05-15T13:24:12+02:00 Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments Bailey, Ian Hemming, Sidney Reilly, Brendan T. Rollinson, Gavyn Williams, Trevor Weber, Michael E. Raymo, Maureen E. Peck, Victoria L. Ronge, Thomas A. Brachfeld, Stefanie O’Connell, Suzanne Tauxe, Lisa Warnock, Jonathan P. Armbrecht, Linda Cardillo, Fabricio G. Du, Zhiheng Fauth, Gerson Garcia, Marga Glueder, Anna Guitard, Michelle Gutjahr, Marcus Hernández-Almeida, Iván Hoem, Frida S. Hwang, Ji-Hwan Iizuka, Mutsumi Kato, Yuji Kenlee, Bridget Martos, Yasmina M. Pérez, Lara F. Seki, Osamu Tripathi, Shubham Zheng, Xufeng 2022-07 application/application/pdf https://hdl.handle.net/20.500.11850/559377 https://doi.org/10.3929/ethz-b-000559377 en eng Wiley info:eu-repo/semantics/altIdentifier/doi/10.1029/2022PA004433 info:eu-repo/semantics/altIdentifier/wos/000825357000001 http://hdl.handle.net/20.500.11850/559377 doi:10.3929/ethz-b-000559377 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International CC-BY Paleoceanography and Paleoclimatology, 37 (7) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2022 ftethz https://doi.org/20.500.11850/559377 https://doi.org/10.3929/ethz-b-000559377 https://doi.org/10.1029/2022PA004433 2023-02-13T01:06:51Z Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediments accumulating in the Scotia Sea are useful to examine for this purpose because they receive iceberg-rafted debris (IBRD) sourced from the Pacific- and Atlantic-facing sectors of West Antarctica. Here we report on the sedimentology and provenance of the oldest of three cm-scale coarse-grained layers recovered from this sea at International Ocean Discovery Program Site U1538. These layers are preserved in opal-rich sediments deposited similar to 1.2 Ma during a relatively warm regional climate. Our microCT-based analysis of the layer's in-situ fabric confirms its ice-rafted origin. We further infer that it is the product of an intense but short-lived episode of IBRD deposition. Based on the petrography of its sand fraction and the Phanerozoic Ar-40/Ar-39 ages of hornblende and mica it contains, we conclude that the IBRD it contains was likely sourced from the Weddell Sea and/or Amundsen Sea embayment(s) of West Antarctica. We attribute the high concentrations of IBRD in these layers to "dirty" icebergs calved from the WAIS following its retreat inland from its modern grounding line. These layers also sit at the top of a similar to 366-m thick Pliocene and early Pleistocene sequence that is much more dropstone-rich than its overlying sediments. We speculate this fact may reflect that WAIS mass-balance was highly dynamic during the similar to 41-kyr (inter)glacial world. ISSN:2572-4525 ISSN:2572-4517 Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Iceberg* Scotia Sea Weddell Sea West Antarctica ETH Zürich Research Collection Antarctic Weddell Sea West Antarctica Scotia Sea Amundsen Sea West Antarctic Ice Sheet Pacific Weddell |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
description |
Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediments accumulating in the Scotia Sea are useful to examine for this purpose because they receive iceberg-rafted debris (IBRD) sourced from the Pacific- and Atlantic-facing sectors of West Antarctica. Here we report on the sedimentology and provenance of the oldest of three cm-scale coarse-grained layers recovered from this sea at International Ocean Discovery Program Site U1538. These layers are preserved in opal-rich sediments deposited similar to 1.2 Ma during a relatively warm regional climate. Our microCT-based analysis of the layer's in-situ fabric confirms its ice-rafted origin. We further infer that it is the product of an intense but short-lived episode of IBRD deposition. Based on the petrography of its sand fraction and the Phanerozoic Ar-40/Ar-39 ages of hornblende and mica it contains, we conclude that the IBRD it contains was likely sourced from the Weddell Sea and/or Amundsen Sea embayment(s) of West Antarctica. We attribute the high concentrations of IBRD in these layers to "dirty" icebergs calved from the WAIS following its retreat inland from its modern grounding line. These layers also sit at the top of a similar to 366-m thick Pliocene and early Pleistocene sequence that is much more dropstone-rich than its overlying sediments. We speculate this fact may reflect that WAIS mass-balance was highly dynamic during the similar to 41-kyr (inter)glacial world. ISSN:2572-4525 ISSN:2572-4517 |
format |
Article in Journal/Newspaper |
author |
Bailey, Ian Hemming, Sidney Reilly, Brendan T. Rollinson, Gavyn Williams, Trevor Weber, Michael E. Raymo, Maureen E. Peck, Victoria L. Ronge, Thomas A. Brachfeld, Stefanie O’Connell, Suzanne Tauxe, Lisa Warnock, Jonathan P. Armbrecht, Linda Cardillo, Fabricio G. Du, Zhiheng Fauth, Gerson Garcia, Marga Glueder, Anna Guitard, Michelle Gutjahr, Marcus Hernández-Almeida, Iván Hoem, Frida S. Hwang, Ji-Hwan Iizuka, Mutsumi Kato, Yuji Kenlee, Bridget Martos, Yasmina M. Pérez, Lara F. Seki, Osamu Tripathi, Shubham Zheng, Xufeng |
spellingShingle |
Bailey, Ian Hemming, Sidney Reilly, Brendan T. Rollinson, Gavyn Williams, Trevor Weber, Michael E. Raymo, Maureen E. Peck, Victoria L. Ronge, Thomas A. Brachfeld, Stefanie O’Connell, Suzanne Tauxe, Lisa Warnock, Jonathan P. Armbrecht, Linda Cardillo, Fabricio G. Du, Zhiheng Fauth, Gerson Garcia, Marga Glueder, Anna Guitard, Michelle Gutjahr, Marcus Hernández-Almeida, Iván Hoem, Frida S. Hwang, Ji-Hwan Iizuka, Mutsumi Kato, Yuji Kenlee, Bridget Martos, Yasmina M. Pérez, Lara F. Seki, Osamu Tripathi, Shubham Zheng, Xufeng Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments |
author_facet |
Bailey, Ian Hemming, Sidney Reilly, Brendan T. Rollinson, Gavyn Williams, Trevor Weber, Michael E. Raymo, Maureen E. Peck, Victoria L. Ronge, Thomas A. Brachfeld, Stefanie O’Connell, Suzanne Tauxe, Lisa Warnock, Jonathan P. Armbrecht, Linda Cardillo, Fabricio G. Du, Zhiheng Fauth, Gerson Garcia, Marga Glueder, Anna Guitard, Michelle Gutjahr, Marcus Hernández-Almeida, Iván Hoem, Frida S. Hwang, Ji-Hwan Iizuka, Mutsumi Kato, Yuji Kenlee, Bridget Martos, Yasmina M. Pérez, Lara F. Seki, Osamu Tripathi, Shubham Zheng, Xufeng |
author_sort |
Bailey, Ian |
title |
Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments |
title_short |
Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments |
title_full |
Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments |
title_fullStr |
Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments |
title_full_unstemmed |
Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments |
title_sort |
episodes of early pleistocene west antarctic ice sheet retreat recorded by iceberg alley sediments |
publisher |
Wiley |
publishDate |
2022 |
url |
https://hdl.handle.net/20.500.11850/559377 https://doi.org/10.3929/ethz-b-000559377 |
geographic |
Antarctic Weddell Sea West Antarctica Scotia Sea Amundsen Sea West Antarctic Ice Sheet Pacific Weddell |
geographic_facet |
Antarctic Weddell Sea West Antarctica Scotia Sea Amundsen Sea West Antarctic Ice Sheet Pacific Weddell |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Iceberg* Scotia Sea Weddell Sea West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Iceberg* Scotia Sea Weddell Sea West Antarctica |
op_source |
Paleoceanography and Paleoclimatology, 37 (7) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2022PA004433 info:eu-repo/semantics/altIdentifier/wos/000825357000001 http://hdl.handle.net/20.500.11850/559377 doi:10.3929/ethz-b-000559377 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/20.500.11850/559377 https://doi.org/10.3929/ethz-b-000559377 https://doi.org/10.1029/2022PA004433 |
_version_ |
1766377993830137856 |