Basal crevasses in Larsen C Ice Shelf and implications for their global abundance
Basal crevasses extend upwards from the base of ice bodies and can penetrate more than halfway through the ice column under conditions found commonly on ice shelves. As a result, they may locally modify the exchange of mass and energy between ice shelf and ocean, and by altering the shelf's mec...
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ftdoajarticles:oai:doaj.org/article:c0d3233bff5b4b5ab1518cf6e20068a5 2023-05-15T13:53:25+02:00 Basal crevasses in Larsen C Ice Shelf and implications for their global abundance A. Luckman D. Jansen B. Kulessa E. C. King P. Sammonds D. I. Benn 2012-01-01T00:00:00Z https://doi.org/10.5194/tc-6-113-2012 https://doaj.org/article/c0d3233bff5b4b5ab1518cf6e20068a5 EN eng Copernicus Publications http://www.the-cryosphere.net/6/113/2012/tc-6-113-2012.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-6-113-2012 1994-0416 1994-0424 https://doaj.org/article/c0d3233bff5b4b5ab1518cf6e20068a5 The Cryosphere, Vol 6, Iss 1, Pp 113-123 (2012) Environmental sciences GE1-350 Geology QE1-996.5 article 2012 ftdoajarticles https://doi.org/10.5194/tc-6-113-2012 2022-12-31T13:46:44Z Basal crevasses extend upwards from the base of ice bodies and can penetrate more than halfway through the ice column under conditions found commonly on ice shelves. As a result, they may locally modify the exchange of mass and energy between ice shelf and ocean, and by altering the shelf's mechanical properties could play a fundamental role in ice shelf stability. Although early studies revealed that such features may be abundant on Antarctic ice shelves, their geometrical properties and spatial distribution has gained little attention. We investigate basal crevasses in Larsen C Ice Shelf using field radar survey, remote sensing and numerical modelling. We demonstrate that a group of features visible in MODIS imagery are the surface expressions of basal crevasses in the form of surface troughs, and find that basal crevasses can be generated as a result of stresses well downstream of the grounding line. We show that linear elastic fracture mechanics modelling is a good predictor of basal crevasse penetration height where stresses are predominantly tensile, and that measured surface trough depth does not always reflect this height, probably because of snow accumulation in the trough, marine ice accretion in the crevasse, or stress bridging from the surrounding ice. We conclude that all features visible in MODIS imagery of ice shelves and previously labelled simply as "crevasses", where they are not full thickness rifts, must be basal crevasse troughs, highlighting a fundamental structural property of many ice shelves that may have been previously overlooked. Article in Journal/Newspaper Antarc* Antarctic Ice Shelf Ice Shelves The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic The Cryosphere 6 1 113 123 |
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 A. Luckman D. Jansen B. Kulessa E. C. King P. Sammonds D. I. Benn Basal crevasses in Larsen C Ice Shelf and implications for their global abundance |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Basal crevasses extend upwards from the base of ice bodies and can penetrate more than halfway through the ice column under conditions found commonly on ice shelves. As a result, they may locally modify the exchange of mass and energy between ice shelf and ocean, and by altering the shelf's mechanical properties could play a fundamental role in ice shelf stability. Although early studies revealed that such features may be abundant on Antarctic ice shelves, their geometrical properties and spatial distribution has gained little attention. We investigate basal crevasses in Larsen C Ice Shelf using field radar survey, remote sensing and numerical modelling. We demonstrate that a group of features visible in MODIS imagery are the surface expressions of basal crevasses in the form of surface troughs, and find that basal crevasses can be generated as a result of stresses well downstream of the grounding line. We show that linear elastic fracture mechanics modelling is a good predictor of basal crevasse penetration height where stresses are predominantly tensile, and that measured surface trough depth does not always reflect this height, probably because of snow accumulation in the trough, marine ice accretion in the crevasse, or stress bridging from the surrounding ice. We conclude that all features visible in MODIS imagery of ice shelves and previously labelled simply as "crevasses", where they are not full thickness rifts, must be basal crevasse troughs, highlighting a fundamental structural property of many ice shelves that may have been previously overlooked. |
format |
Article in Journal/Newspaper |
author |
A. Luckman D. Jansen B. Kulessa E. C. King P. Sammonds D. I. Benn |
author_facet |
A. Luckman D. Jansen B. Kulessa E. C. King P. Sammonds D. I. Benn |
author_sort |
A. Luckman |
title |
Basal crevasses in Larsen C Ice Shelf and implications for their global abundance |
title_short |
Basal crevasses in Larsen C Ice Shelf and implications for their global abundance |
title_full |
Basal crevasses in Larsen C Ice Shelf and implications for their global abundance |
title_fullStr |
Basal crevasses in Larsen C Ice Shelf and implications for their global abundance |
title_full_unstemmed |
Basal crevasses in Larsen C Ice Shelf and implications for their global abundance |
title_sort |
basal crevasses in larsen c ice shelf and implications for their global abundance |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/tc-6-113-2012 https://doaj.org/article/c0d3233bff5b4b5ab1518cf6e20068a5 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Ice Shelf Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Shelf Ice Shelves The Cryosphere |
op_source |
The Cryosphere, Vol 6, Iss 1, Pp 113-123 (2012) |
op_relation |
http://www.the-cryosphere.net/6/113/2012/tc-6-113-2012.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-6-113-2012 1994-0416 1994-0424 https://doaj.org/article/c0d3233bff5b4b5ab1518cf6e20068a5 |
op_doi |
https://doi.org/10.5194/tc-6-113-2012 |
container_title |
The Cryosphere |
container_volume |
6 |
container_issue |
1 |
container_start_page |
113 |
op_container_end_page |
123 |
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1766258509453721600 |