Measurement of temperature in a margin of Ice Stream B, Antarctica: implications for margin migration and lateral drag
Abstract Ice temperature was measured in and around the chaotically crevassed south margin of Ice Stream B, Antarctica, from 1992 to 1994. The temperatures at 30 m depth in the chaotic zone are about 12 K lower than in the adjacent uncrevassed ice, due to the ponding of cold winter air. At depths gr...
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1998
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Online Access: | http://dx.doi.org/10.1017/s0022143000002112 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002112 |
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crcambridgeupr:10.1017/s0022143000002112 2024-09-15T17:48:37+00:00 Measurement of temperature in a margin of Ice Stream B, Antarctica: implications for margin migration and lateral drag Harrison, W. D. Echelmeyer, K. A. Larsen, C. F. 1998 http://dx.doi.org/10.1017/s0022143000002112 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002112 en eng Cambridge University Press (CUP) Journal of Glaciology volume 44, issue 148, page 615-624 ISSN 0022-1430 1727-5652 journal-article 1998 crcambridgeupr https://doi.org/10.1017/s0022143000002112 2024-07-31T04:04:10Z Abstract Ice temperature was measured in and around the chaotically crevassed south margin of Ice Stream B, Antarctica, from 1992 to 1994. The temperatures at 30 m depth in the chaotic zone are about 12 K lower than in the adjacent uncrevassed ice, due to the ponding of cold winter air. At depths greater than 150 m, there is clear evidence of internal heating of the ice due to the large shear déformation rate in the marginal zone. Analysis of the depth of cooling below the crevasses and of the internal heating gives two pieces of information. First, over the last half century the lateral shear stress averaged 2.0 x 10 5 Pa in the top third of the margin and, second, the margin moved outward at an average rate of 7.3 m a −1 . These values do not involve any assumptions about the How law of ice. The uncertainties are roughly 20%. The value of lateral shear stress indicates that the most of the drag on the ice stream is along its sides. Article in Journal/Newspaper Antarc* Antarctica Ice Stream B Journal of Glaciology Cambridge University Press Journal of Glaciology 44 148 615 624 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract Ice temperature was measured in and around the chaotically crevassed south margin of Ice Stream B, Antarctica, from 1992 to 1994. The temperatures at 30 m depth in the chaotic zone are about 12 K lower than in the adjacent uncrevassed ice, due to the ponding of cold winter air. At depths greater than 150 m, there is clear evidence of internal heating of the ice due to the large shear déformation rate in the marginal zone. Analysis of the depth of cooling below the crevasses and of the internal heating gives two pieces of information. First, over the last half century the lateral shear stress averaged 2.0 x 10 5 Pa in the top third of the margin and, second, the margin moved outward at an average rate of 7.3 m a −1 . These values do not involve any assumptions about the How law of ice. The uncertainties are roughly 20%. The value of lateral shear stress indicates that the most of the drag on the ice stream is along its sides. |
format |
Article in Journal/Newspaper |
author |
Harrison, W. D. Echelmeyer, K. A. Larsen, C. F. |
spellingShingle |
Harrison, W. D. Echelmeyer, K. A. Larsen, C. F. Measurement of temperature in a margin of Ice Stream B, Antarctica: implications for margin migration and lateral drag |
author_facet |
Harrison, W. D. Echelmeyer, K. A. Larsen, C. F. |
author_sort |
Harrison, W. D. |
title |
Measurement of temperature in a margin of Ice Stream B, Antarctica: implications for margin migration and lateral drag |
title_short |
Measurement of temperature in a margin of Ice Stream B, Antarctica: implications for margin migration and lateral drag |
title_full |
Measurement of temperature in a margin of Ice Stream B, Antarctica: implications for margin migration and lateral drag |
title_fullStr |
Measurement of temperature in a margin of Ice Stream B, Antarctica: implications for margin migration and lateral drag |
title_full_unstemmed |
Measurement of temperature in a margin of Ice Stream B, Antarctica: implications for margin migration and lateral drag |
title_sort |
measurement of temperature in a margin of ice stream b, antarctica: implications for margin migration and lateral drag |
publisher |
Cambridge University Press (CUP) |
publishDate |
1998 |
url |
http://dx.doi.org/10.1017/s0022143000002112 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002112 |
genre |
Antarc* Antarctica Ice Stream B Journal of Glaciology |
genre_facet |
Antarc* Antarctica Ice Stream B Journal of Glaciology |
op_source |
Journal of Glaciology volume 44, issue 148, page 615-624 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000002112 |
container_title |
Journal of Glaciology |
container_volume |
44 |
container_issue |
148 |
container_start_page |
615 |
op_container_end_page |
624 |
_version_ |
1810290056607301632 |