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...
Published in: | Paleoceanography and Paleoclimatology |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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American Geophysical Union
2022
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Online Access: | http://nora.nerc.ac.uk/id/eprint/532789/ https://nora.nerc.ac.uk/id/eprint/532789/7/Paleoceanog%20and%20Paleoclimatol%20-%202022%20-%20Bailey%20-%20Episodes%20of%20Early%20Pleistocene%20West%20Antarctic%20Ice%20Sheet%20Retreat%20Recorded%20by.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022PA004433 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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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 centimeter-scale coarse-grained layers recovered from this sea at IODP Site U1538. These layers are preserved in opal-rich sediments deposited ∼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 40Ar/39Ar ages of hornblende and mica it contains, we conclude that this IBRD 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 ∼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 ∼41-kyr (inter)glacial world. |
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, Ivan Hoem, Frida S. Hwang, Ji‐Hwan Iizuka, Mutsumi Kato, Yuji Kenlee, Bridget Martos, Yasmina M. Perez, 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, Ivan Hoem, Frida S. Hwang, Ji‐Hwan Iizuka, Mutsumi Kato, Yuji Kenlee, Bridget Martos, Yasmina M. Perez, 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, Ivan Hoem, Frida S. Hwang, Ji‐Hwan Iizuka, Mutsumi Kato, Yuji Kenlee, Bridget Martos, Yasmina M. Perez, 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 |
American Geophysical Union |
publishDate |
2022 |
url |
http://nora.nerc.ac.uk/id/eprint/532789/ https://nora.nerc.ac.uk/id/eprint/532789/7/Paleoceanog%20and%20Paleoclimatol%20-%202022%20-%20Bailey%20-%20Episodes%20of%20Early%20Pleistocene%20West%20Antarctic%20Ice%20Sheet%20Retreat%20Recorded%20by.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022PA004433 |
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_relation |
https://nora.nerc.ac.uk/id/eprint/532789/7/Paleoceanog%20and%20Paleoclimatol%20-%202022%20-%20Bailey%20-%20Episodes%20of%20Early%20Pleistocene%20West%20Antarctic%20Ice%20Sheet%20Retreat%20Recorded%20by.pdf Bailey, Ian; Hemming, Sidney; Reilly, Brendan T.; Rollinson, Gavyn; Williams, Trevor; Weber, Michael E.; Raymo, Maureen E.; Peck, Victoria L. orcid:0000-0002-7948-6853 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, Ivan; Hoem, Frida S.; Hwang, Ji‐Hwan; Iizuka, Mutsumi; Kato, Yuji; Kenlee, Bridget; Martos, Yasmina M.; Perez, Lara F. orcid:0000-0002-6229-4564 Seki, Osamu; Tripathi, Shubham; Zheng, Xufeng. 2022 Episodes of early Pleistocene West Antarctic Ice Sheet retreat recorded by Iceberg Alley sediments. Paleoceanography and Paleoclimatology, 37 (7), e2022PA004433. 26, pp. https://doi.org/10.1029/2022PA004433 <https://doi.org/10.1029/2022PA004433> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2022PA004433 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
37 |
container_issue |
7 |
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1766377997833601024 |
spelling |
ftnerc:oai:nora.nerc.ac.uk:532789 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, Ivan Hoem, Frida S. Hwang, Ji‐Hwan Iizuka, Mutsumi Kato, Yuji Kenlee, Bridget Martos, Yasmina M. Perez, Lara F. Seki, Osamu Tripathi, Shubham Zheng, Xufeng 2022-07 text http://nora.nerc.ac.uk/id/eprint/532789/ https://nora.nerc.ac.uk/id/eprint/532789/7/Paleoceanog%20and%20Paleoclimatol%20-%202022%20-%20Bailey%20-%20Episodes%20of%20Early%20Pleistocene%20West%20Antarctic%20Ice%20Sheet%20Retreat%20Recorded%20by.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022PA004433 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/532789/7/Paleoceanog%20and%20Paleoclimatol%20-%202022%20-%20Bailey%20-%20Episodes%20of%20Early%20Pleistocene%20West%20Antarctic%20Ice%20Sheet%20Retreat%20Recorded%20by.pdf Bailey, Ian; Hemming, Sidney; Reilly, Brendan T.; Rollinson, Gavyn; Williams, Trevor; Weber, Michael E.; Raymo, Maureen E.; Peck, Victoria L. orcid:0000-0002-7948-6853 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, Ivan; Hoem, Frida S.; Hwang, Ji‐Hwan; Iizuka, Mutsumi; Kato, Yuji; Kenlee, Bridget; Martos, Yasmina M.; Perez, Lara F. orcid:0000-0002-6229-4564 Seki, Osamu; Tripathi, Shubham; Zheng, Xufeng. 2022 Episodes of early Pleistocene West Antarctic Ice Sheet retreat recorded by Iceberg Alley sediments. Paleoceanography and Paleoclimatology, 37 (7), e2022PA004433. 26, pp. https://doi.org/10.1029/2022PA004433 <https://doi.org/10.1029/2022PA004433> cc_by_4 CC-BY Publication - Article PeerReviewed 2022 ftnerc https://doi.org/10.1029/2022PA004433 2023-02-04T19:53:22Z 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 centimeter-scale coarse-grained layers recovered from this sea at IODP Site U1538. These layers are preserved in opal-rich sediments deposited ∼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 40Ar/39Ar ages of hornblende and mica it contains, we conclude that this IBRD 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 ∼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 ∼41-kyr (inter)glacial world. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Iceberg* Scotia Sea Weddell Sea West Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic Weddell Sea West Antarctica Scotia Sea Amundsen Sea West Antarctic Ice Sheet Pacific Weddell Paleoceanography and Paleoclimatology 37 7 |