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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Online Access: | http://nora.nerc.ac.uk/id/eprint/17363/ https://nora.nerc.ac.uk/id/eprint/17363/1/tc-6-113-2012.pdf http://www.the-cryosphere.net/6/113/2012/tc-6-113-2012.pdf |
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ftnerc:oai:nora.nerc.ac.uk:17363 2023-05-15T13:45:12+02:00 Basal crevasses in Larsen C Ice Shelf and implications for their global abundance Luckman, A. Jansen, D. Kulessa, B. King, Edward Sammonds, P. Benn, D.I. 2012 text http://nora.nerc.ac.uk/id/eprint/17363/ https://nora.nerc.ac.uk/id/eprint/17363/1/tc-6-113-2012.pdf http://www.the-cryosphere.net/6/113/2012/tc-6-113-2012.pdf en eng Copernicus https://nora.nerc.ac.uk/id/eprint/17363/1/tc-6-113-2012.pdf Luckman, A.; Jansen, D.; Kulessa, B.; King, Edward orcid:0000-0003-3793-3915 Sammonds, P.; Benn, D.I. 2012 Basal crevasses in Larsen C Ice Shelf and implications for their global abundance. The Cryosphere, 6 (1). 113-123. https://doi.org/10.5194/tc-6-113-2012 <https://doi.org/10.5194/tc-6-113-2012> Publication - Article PeerReviewed 2012 ftnerc https://doi.org/10.5194/tc-6-113-2012 2023-02-04T19:31:05Z 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 Natural Environment Research Council: NERC Open Research Archive Antarctic The Cryosphere 6 1 113 123 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
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 |
Luckman, A. Jansen, D. Kulessa, B. King, Edward Sammonds, P. Benn, D.I. |
spellingShingle |
Luckman, A. Jansen, D. Kulessa, B. King, Edward Sammonds, P. Benn, D.I. Basal crevasses in Larsen C Ice Shelf and implications for their global abundance |
author_facet |
Luckman, A. Jansen, D. Kulessa, B. King, Edward Sammonds, P. Benn, D.I. |
author_sort |
Luckman, A. |
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 |
publishDate |
2012 |
url |
http://nora.nerc.ac.uk/id/eprint/17363/ https://nora.nerc.ac.uk/id/eprint/17363/1/tc-6-113-2012.pdf http://www.the-cryosphere.net/6/113/2012/tc-6-113-2012.pdf |
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_relation |
https://nora.nerc.ac.uk/id/eprint/17363/1/tc-6-113-2012.pdf Luckman, A.; Jansen, D.; Kulessa, B.; King, Edward orcid:0000-0003-3793-3915 Sammonds, P.; Benn, D.I. 2012 Basal crevasses in Larsen C Ice Shelf and implications for their global abundance. The Cryosphere, 6 (1). 113-123. https://doi.org/10.5194/tc-6-113-2012 <https://doi.org/10.5194/tc-6-113-2012> |
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 |
_version_ |
1766216270674395136 |