Kinematic first-order calving law implies potential for abrupt ice-shelf retreat
Recently observed large-scale disintegration of Antarctic ice shelves has moved their fronts closer towards grounded ice. In response, ice-sheet discharge into the ocean has accelerated, contributing to global sea-level rise and emphasizing the importance of calving-front dynamics. The position of t...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2012
|
Subjects: | |
Online Access: | https://publishup.uni-potsdam.de/frontdoor/index/index/docId/36310 https://doi.org/10.5194/tc-6-273-2012 |
id |
ftubpotsdam:oai:kobv.de-opus4-uni-potsdam:36310 |
---|---|
record_format |
openpolar |
spelling |
ftubpotsdam:oai:kobv.de-opus4-uni-potsdam:36310 2024-05-19T07:32:26+00:00 Kinematic first-order calving law implies potential for abrupt ice-shelf retreat Levermann, Anders (Prof. Dr.) Albrecht, Tanja Winkelmann, Ricarda (Prof. Dr.) Martin, Maria A. Haseloff, Monika Joughin, I. 2012 https://publishup.uni-potsdam.de/frontdoor/index/index/docId/36310 https://doi.org/10.5194/tc-6-273-2012 eng eng https://publishup.uni-potsdam.de/frontdoor/index/index/docId/36310 https://doi.org/10.5194/tc-6-273-2012 info:eu-repo/semantics/closedAccess Institut für Geowissenschaften article doc-type:article 2012 ftubpotsdam https://doi.org/10.5194/tc-6-273-2012 2024-04-23T23:32:43Z Recently observed large-scale disintegration of Antarctic ice shelves has moved their fronts closer towards grounded ice. In response, ice-sheet discharge into the ocean has accelerated, contributing to global sea-level rise and emphasizing the importance of calving-front dynamics. The position of the ice front strongly influences the stress field within the entire sheet-shelf-system and thereby the mass flow across the grounding line. While theories for an advance of the ice-front are readily available, no general rule exists for its retreat, making it difficult to incorporate the retreat in predictive models. Here we extract the first-order large-scale kinematic contribution to calving which is consistent with large-scale observation. We emphasize that the proposed equation does not constitute a comprehensive calving law but represents the first-order kinematic contribution which can and should be complemented by higher order contributions as well as the influence of potentially heterogeneous material properties of the ice. When applied as a calving law, the equation naturally incorporates the stabilizing effect of pinning points and inhibits ice shelf growth outside of embayments. It depends only on local ice properties which are, however, determined by the full topography of the ice shelf. In numerical simulations the parameterization reproduces multiple stable fronts as observed for the Larsen A and B Ice Shelves including abrupt transitions between them which may be caused by localized ice weaknesses. We also find multiple stable states of the Ross Ice Shelf at the gateway of the West Antarctic Ice Sheet with back stresses onto the sheet reduced by up to 90 % compared to the present state. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf University of Potsdam: publish.UP The Cryosphere 6 2 273 286 |
institution |
Open Polar |
collection |
University of Potsdam: publish.UP |
op_collection_id |
ftubpotsdam |
language |
English |
topic |
Institut für Geowissenschaften |
spellingShingle |
Institut für Geowissenschaften Levermann, Anders (Prof. Dr.) Albrecht, Tanja Winkelmann, Ricarda (Prof. Dr.) Martin, Maria A. Haseloff, Monika Joughin, I. Kinematic first-order calving law implies potential for abrupt ice-shelf retreat |
topic_facet |
Institut für Geowissenschaften |
description |
Recently observed large-scale disintegration of Antarctic ice shelves has moved their fronts closer towards grounded ice. In response, ice-sheet discharge into the ocean has accelerated, contributing to global sea-level rise and emphasizing the importance of calving-front dynamics. The position of the ice front strongly influences the stress field within the entire sheet-shelf-system and thereby the mass flow across the grounding line. While theories for an advance of the ice-front are readily available, no general rule exists for its retreat, making it difficult to incorporate the retreat in predictive models. Here we extract the first-order large-scale kinematic contribution to calving which is consistent with large-scale observation. We emphasize that the proposed equation does not constitute a comprehensive calving law but represents the first-order kinematic contribution which can and should be complemented by higher order contributions as well as the influence of potentially heterogeneous material properties of the ice. When applied as a calving law, the equation naturally incorporates the stabilizing effect of pinning points and inhibits ice shelf growth outside of embayments. It depends only on local ice properties which are, however, determined by the full topography of the ice shelf. In numerical simulations the parameterization reproduces multiple stable fronts as observed for the Larsen A and B Ice Shelves including abrupt transitions between them which may be caused by localized ice weaknesses. We also find multiple stable states of the Ross Ice Shelf at the gateway of the West Antarctic Ice Sheet with back stresses onto the sheet reduced by up to 90 % compared to the present state. |
format |
Article in Journal/Newspaper |
author |
Levermann, Anders (Prof. Dr.) Albrecht, Tanja Winkelmann, Ricarda (Prof. Dr.) Martin, Maria A. Haseloff, Monika Joughin, I. |
author_facet |
Levermann, Anders (Prof. Dr.) Albrecht, Tanja Winkelmann, Ricarda (Prof. Dr.) Martin, Maria A. Haseloff, Monika Joughin, I. |
author_sort |
Levermann, Anders (Prof. Dr.) |
title |
Kinematic first-order calving law implies potential for abrupt ice-shelf retreat |
title_short |
Kinematic first-order calving law implies potential for abrupt ice-shelf retreat |
title_full |
Kinematic first-order calving law implies potential for abrupt ice-shelf retreat |
title_fullStr |
Kinematic first-order calving law implies potential for abrupt ice-shelf retreat |
title_full_unstemmed |
Kinematic first-order calving law implies potential for abrupt ice-shelf retreat |
title_sort |
kinematic first-order calving law implies potential for abrupt ice-shelf retreat |
publishDate |
2012 |
url |
https://publishup.uni-potsdam.de/frontdoor/index/index/docId/36310 https://doi.org/10.5194/tc-6-273-2012 |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf |
op_relation |
https://publishup.uni-potsdam.de/frontdoor/index/index/docId/36310 https://doi.org/10.5194/tc-6-273-2012 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.5194/tc-6-273-2012 |
container_title |
The Cryosphere |
container_volume |
6 |
container_issue |
2 |
container_start_page |
273 |
op_container_end_page |
286 |
_version_ |
1799470474039656448 |