Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode
Abstract: The Antarctic Peninsula Ice Sheet is currently experiencing sustained and accelerating loss of ice. Determining when these changes were initiated and identifying the main drivers is hampered by the short instrumental record (1992 to present). Here we present a 6,250 year record of glacial...
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ftunivcam:oai:www.repository.cam.ac.uk:1810/311873 2023-07-30T03:56:26+02:00 Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode Dickens, W. A. Kuhn, G. Leng, M. J. Graham, A. G. C. Dowdeswell, J. A. Meredith, M. P. Hillenbrand, C.-D. Hodgson, D. A. Roberts, S. J. Sloane, H. Smith, J. A. 2020-10-23T15:19:54Z application/pdf text/xml https://doi.org/10.17863/CAM.58965 https://www.repository.cam.ac.uk/handle/1810/311873 en eng Nature Publishing Group UK Scientific Reports doi:10.17863/CAM.58965 https://www.repository.cam.ac.uk/handle/1810/311873 Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ Article /704/106/125 /704/106/413 Article 2020 ftunivcam https://doi.org/10.17863/CAM.58965 2023-07-10T21:43:11Z Abstract: The Antarctic Peninsula Ice Sheet is currently experiencing sustained and accelerating loss of ice. Determining when these changes were initiated and identifying the main drivers is hampered by the short instrumental record (1992 to present). Here we present a 6,250 year record of glacial discharge based on the oxygen isotope composition of diatoms (δ18Odiatom) from a marine core located at the north-eastern tip of the Antarctic Peninsula. We find that glacial discharge - sourced primarily from ice shelf and iceberg melting along the eastern Antarctic Peninsula – remained largely stable between ~6,250 to 1,620 cal. yr BP, with a slight increase in variability until ~720 cal. yr. BP. An increasing trend in glacial discharge occurs after 550 cal. yr BP (A.D. 1400), reaching levels unprecedented during the past 6,250 years after 244 cal. yr BP (A.D. 1706). A marked acceleration in the rate of glacial discharge is also observed in the early part of twentieth century (after A.D. 1912). Enhanced glacial discharge, particularly after the 1700s is linked to a positive Southern Annular Mode (SAM). We argue that a positive SAM drove stronger westerly winds, atmospheric warming and surface ablation on the eastern Antarctic Peninsula whilst simultaneously entraining more warm water into the Weddell Gyre, potentially increasing melting on the undersides of ice shelves. A possible implication of our data is that ice shelves in this region have been thinning for at least ~300 years, potentially predisposing them to collapse under intensified anthropogenic warming. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Ice Sheet Ice Shelf Ice Shelves Iceberg* Apollo - University of Cambridge Repository Antarctic Antarctic Peninsula The Antarctic Weddell |
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Open Polar |
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Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Article /704/106/125 /704/106/413 |
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Article /704/106/125 /704/106/413 Dickens, W. A. Kuhn, G. Leng, M. J. Graham, A. G. C. Dowdeswell, J. A. Meredith, M. P. Hillenbrand, C.-D. Hodgson, D. A. Roberts, S. J. Sloane, H. Smith, J. A. Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode |
topic_facet |
Article /704/106/125 /704/106/413 |
description |
Abstract: The Antarctic Peninsula Ice Sheet is currently experiencing sustained and accelerating loss of ice. Determining when these changes were initiated and identifying the main drivers is hampered by the short instrumental record (1992 to present). Here we present a 6,250 year record of glacial discharge based on the oxygen isotope composition of diatoms (δ18Odiatom) from a marine core located at the north-eastern tip of the Antarctic Peninsula. We find that glacial discharge - sourced primarily from ice shelf and iceberg melting along the eastern Antarctic Peninsula – remained largely stable between ~6,250 to 1,620 cal. yr BP, with a slight increase in variability until ~720 cal. yr. BP. An increasing trend in glacial discharge occurs after 550 cal. yr BP (A.D. 1400), reaching levels unprecedented during the past 6,250 years after 244 cal. yr BP (A.D. 1706). A marked acceleration in the rate of glacial discharge is also observed in the early part of twentieth century (after A.D. 1912). Enhanced glacial discharge, particularly after the 1700s is linked to a positive Southern Annular Mode (SAM). We argue that a positive SAM drove stronger westerly winds, atmospheric warming and surface ablation on the eastern Antarctic Peninsula whilst simultaneously entraining more warm water into the Weddell Gyre, potentially increasing melting on the undersides of ice shelves. A possible implication of our data is that ice shelves in this region have been thinning for at least ~300 years, potentially predisposing them to collapse under intensified anthropogenic warming. |
format |
Article in Journal/Newspaper |
author |
Dickens, W. A. Kuhn, G. Leng, M. J. Graham, A. G. C. Dowdeswell, J. A. Meredith, M. P. Hillenbrand, C.-D. Hodgson, D. A. Roberts, S. J. Sloane, H. Smith, J. A. |
author_facet |
Dickens, W. A. Kuhn, G. Leng, M. J. Graham, A. G. C. Dowdeswell, J. A. Meredith, M. P. Hillenbrand, C.-D. Hodgson, D. A. Roberts, S. J. Sloane, H. Smith, J. A. |
author_sort |
Dickens, W. A. |
title |
Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode |
title_short |
Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode |
title_full |
Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode |
title_fullStr |
Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode |
title_full_unstemmed |
Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode |
title_sort |
enhanced glacial discharge from the eastern antarctic peninsula since the 1700s associated with a positive southern annular mode |
publisher |
Nature Publishing Group UK |
publishDate |
2020 |
url |
https://doi.org/10.17863/CAM.58965 https://www.repository.cam.ac.uk/handle/1810/311873 |
geographic |
Antarctic Antarctic Peninsula The Antarctic Weddell |
geographic_facet |
Antarctic Antarctic Peninsula The Antarctic Weddell |
genre |
Antarc* Antarctic Antarctic Peninsula Ice Sheet Ice Shelf Ice Shelves Iceberg* |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Ice Sheet Ice Shelf Ice Shelves Iceberg* |
op_relation |
doi:10.17863/CAM.58965 https://www.repository.cam.ac.uk/handle/1810/311873 |
op_rights |
Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.17863/CAM.58965 |
_version_ |
1772813204405092352 |