Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68
The sudden propagation of a major preexisting rift (full-thickness crack) in late 2016 on the Larsen C Ice Shelf, Antarctica led to the calving of tabular iceberg A68 in July 2017, one of the largest icebergs on record, posing a threat for the stability of the remaining ice shelf. As with other ice...
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ftcdlib:oai:escholarship.org:ark:/13030/qt7377045m 2023-09-05T13:12:16+02:00 Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68 Larour, E Rignot, E Poinelli, M Scheuchl, B e2105080118 2021-10-05 application/pdf https://escholarship.org/uc/item/7377045m unknown eScholarship, University of California qt7377045m https://escholarship.org/uc/item/7377045m public Proceedings of the National Academy of Sciences of the United States of America, vol 118, iss 40 Climate Action Larsen C Antarctica sea level ice shelf fracture article 2021 ftcdlib 2023-08-21T18:04:51Z The sudden propagation of a major preexisting rift (full-thickness crack) in late 2016 on the Larsen C Ice Shelf, Antarctica led to the calving of tabular iceberg A68 in July 2017, one of the largest icebergs on record, posing a threat for the stability of the remaining ice shelf. As with other ice shelves, the physical processes that led to the activation of the A68 rift and controlled its propagation have not been elucidated. Here, we model the response of the ice shelf stress balance to ice shelf thinning and thinning of the ice mélange encased in and around preexisting rifts. We find that ice shelf thinning does not reactivate the rifts, but heals them. In contrast, thinning of the mélange controls the opening rate of the rift, with an above-linear dependence on thinning. The simulations indicate that thinning of the ice mélange by 10 to 20 m is sufficient to reactivate the rifts and trigger a major calving event, thereby establishing a link between climate forcing and ice shelf retreat that has not been included in ice sheet models. Rift activation could initiate ice shelf retreat decades prior to hydrofracture caused by water ponding at the ice shelf surface. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves University of California: eScholarship |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Climate Action Larsen C Antarctica sea level ice shelf fracture |
spellingShingle |
Climate Action Larsen C Antarctica sea level ice shelf fracture Larour, E Rignot, E Poinelli, M Scheuchl, B Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68 |
topic_facet |
Climate Action Larsen C Antarctica sea level ice shelf fracture |
description |
The sudden propagation of a major preexisting rift (full-thickness crack) in late 2016 on the Larsen C Ice Shelf, Antarctica led to the calving of tabular iceberg A68 in July 2017, one of the largest icebergs on record, posing a threat for the stability of the remaining ice shelf. As with other ice shelves, the physical processes that led to the activation of the A68 rift and controlled its propagation have not been elucidated. Here, we model the response of the ice shelf stress balance to ice shelf thinning and thinning of the ice mélange encased in and around preexisting rifts. We find that ice shelf thinning does not reactivate the rifts, but heals them. In contrast, thinning of the mélange controls the opening rate of the rift, with an above-linear dependence on thinning. The simulations indicate that thinning of the ice mélange by 10 to 20 m is sufficient to reactivate the rifts and trigger a major calving event, thereby establishing a link between climate forcing and ice shelf retreat that has not been included in ice sheet models. Rift activation could initiate ice shelf retreat decades prior to hydrofracture caused by water ponding at the ice shelf surface. |
format |
Article in Journal/Newspaper |
author |
Larour, E Rignot, E Poinelli, M Scheuchl, B |
author_facet |
Larour, E Rignot, E Poinelli, M Scheuchl, B |
author_sort |
Larour, E |
title |
Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68 |
title_short |
Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68 |
title_full |
Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68 |
title_fullStr |
Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68 |
title_full_unstemmed |
Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68 |
title_sort |
physical processes controlling the rifting of larsen c ice shelf, antarctica, prior to the calving of iceberg a68 |
publisher |
eScholarship, University of California |
publishDate |
2021 |
url |
https://escholarship.org/uc/item/7377045m |
op_coverage |
e2105080118 |
genre |
Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves |
op_source |
Proceedings of the National Academy of Sciences of the United States of America, vol 118, iss 40 |
op_relation |
qt7377045m https://escholarship.org/uc/item/7377045m |
op_rights |
public |
_version_ |
1776199559843676160 |