Widespread slowdown in thinning rates of West Antarctic ice shelves
Antarctica's floating ice shelves modulate discharge of grounded ice into the ocean by providing a backstress. Ice shelf thinning and grounding line retreat have reduced this backstress, driving rapid drawdown of key unstable areas of the Antarctic Ice Sheet, leading to sea-level rise. If ice s...
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Copernicus Publications
2023
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Online Access: | https://doi.org/10.5194/tc-17-3409-2023 https://doaj.org/article/7ec53fb026704a78a7ce95d2de64a3f3 |
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ftdoajarticles:oai:doaj.org/article:7ec53fb026704a78a7ce95d2de64a3f3 2023-09-26T15:11:07+02:00 Widespread slowdown in thinning rates of West Antarctic ice shelves F. S. Paolo A. S. Gardner C. A. Greene J. Nilsson M. P. Schodlok N.-J. Schlegel H. A. Fricker 2023-08-01T00:00:00Z https://doi.org/10.5194/tc-17-3409-2023 https://doaj.org/article/7ec53fb026704a78a7ce95d2de64a3f3 EN eng Copernicus Publications https://tc.copernicus.org/articles/17/3409/2023/tc-17-3409-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-3409-2023 1994-0416 1994-0424 https://doaj.org/article/7ec53fb026704a78a7ce95d2de64a3f3 The Cryosphere, Vol 17, Pp 3409-3433 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-3409-2023 2023-08-27T00:37:43Z Antarctica's floating ice shelves modulate discharge of grounded ice into the ocean by providing a backstress. Ice shelf thinning and grounding line retreat have reduced this backstress, driving rapid drawdown of key unstable areas of the Antarctic Ice Sheet, leading to sea-level rise. If ice shelf loss continues, it may initiate irreversible glacier retreat through the marine ice sheet instability. Identification of areas undergoing significant change requires knowledge of spatial and temporal patterns in recent ice shelf loss. We used 26 years (1992–2017) of satellite-derived Antarctic ice shelf thickness, flow, and basal melt rates to construct a time-dependent dataset of ice shelf thickness and basal melt on a 3 km grid every 3 months. We used a novel data fusion approach, state-of-the-art satellite-derived velocities, and a new surface mass balance model. Our data revealed an overall pattern of thinning all around Antarctica, with a thinning slowdown starting around 2008 widespread across the Amundsen, Bellingshausen, and Wilkes sectors. We attribute this slowdown partly to modulation in external ocean forcing, altered in West Antarctica by negative feedbacks between ice shelf thinning rates and grounded ice flow, and sub-ice-shelf cavity geometry and basal melting. In agreement with earlier studies, the highest rates of ice shelf thinning are found for those ice shelves located in the Amundsen and Bellingshausen sectors. Our study reveals that over the 1992–2017 observational period the Amundsen and Bellingshausen ice shelves experienced a slight reduction in rates of basal melting, suggesting that high rates of thinning are largely a response to changes in ocean conditions that predate our satellite altimetry record, with shorter-term variability only resulting in small deviations from the long-term trend. Our work demonstrates that causal inference drawn from ice shelf thinning and basal melt rates must take into account complex feedbacks between thinning and ice advection and between ice shelf draft and ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere West Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic West Antarctica The Cryosphere 17 8 3409 3433 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 F. S. Paolo A. S. Gardner C. A. Greene J. Nilsson M. P. Schodlok N.-J. Schlegel H. A. Fricker Widespread slowdown in thinning rates of West Antarctic ice shelves |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Antarctica's floating ice shelves modulate discharge of grounded ice into the ocean by providing a backstress. Ice shelf thinning and grounding line retreat have reduced this backstress, driving rapid drawdown of key unstable areas of the Antarctic Ice Sheet, leading to sea-level rise. If ice shelf loss continues, it may initiate irreversible glacier retreat through the marine ice sheet instability. Identification of areas undergoing significant change requires knowledge of spatial and temporal patterns in recent ice shelf loss. We used 26 years (1992–2017) of satellite-derived Antarctic ice shelf thickness, flow, and basal melt rates to construct a time-dependent dataset of ice shelf thickness and basal melt on a 3 km grid every 3 months. We used a novel data fusion approach, state-of-the-art satellite-derived velocities, and a new surface mass balance model. Our data revealed an overall pattern of thinning all around Antarctica, with a thinning slowdown starting around 2008 widespread across the Amundsen, Bellingshausen, and Wilkes sectors. We attribute this slowdown partly to modulation in external ocean forcing, altered in West Antarctica by negative feedbacks between ice shelf thinning rates and grounded ice flow, and sub-ice-shelf cavity geometry and basal melting. In agreement with earlier studies, the highest rates of ice shelf thinning are found for those ice shelves located in the Amundsen and Bellingshausen sectors. Our study reveals that over the 1992–2017 observational period the Amundsen and Bellingshausen ice shelves experienced a slight reduction in rates of basal melting, suggesting that high rates of thinning are largely a response to changes in ocean conditions that predate our satellite altimetry record, with shorter-term variability only resulting in small deviations from the long-term trend. Our work demonstrates that causal inference drawn from ice shelf thinning and basal melt rates must take into account complex feedbacks between thinning and ice advection and between ice shelf draft and ... |
format |
Article in Journal/Newspaper |
author |
F. S. Paolo A. S. Gardner C. A. Greene J. Nilsson M. P. Schodlok N.-J. Schlegel H. A. Fricker |
author_facet |
F. S. Paolo A. S. Gardner C. A. Greene J. Nilsson M. P. Schodlok N.-J. Schlegel H. A. Fricker |
author_sort |
F. S. Paolo |
title |
Widespread slowdown in thinning rates of West Antarctic ice shelves |
title_short |
Widespread slowdown in thinning rates of West Antarctic ice shelves |
title_full |
Widespread slowdown in thinning rates of West Antarctic ice shelves |
title_fullStr |
Widespread slowdown in thinning rates of West Antarctic ice shelves |
title_full_unstemmed |
Widespread slowdown in thinning rates of West Antarctic ice shelves |
title_sort |
widespread slowdown in thinning rates of west antarctic ice shelves |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-3409-2023 https://doaj.org/article/7ec53fb026704a78a7ce95d2de64a3f3 |
geographic |
Antarctic The Antarctic West Antarctica |
geographic_facet |
Antarctic The Antarctic West Antarctica |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere West Antarctica |
op_source |
The Cryosphere, Vol 17, Pp 3409-3433 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/3409/2023/tc-17-3409-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-3409-2023 1994-0416 1994-0424 https://doaj.org/article/7ec53fb026704a78a7ce95d2de64a3f3 |
op_doi |
https://doi.org/10.5194/tc-17-3409-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
8 |
container_start_page |
3409 |
op_container_end_page |
3433 |
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1778150961758339072 |