Structure and Flow in the Margin of the Barnes Ice Cap, Baffin Island, N.W.T., Canada
The structure and flow field in the margin of the Barnes Ice Cap was determined through observations on the ice-cap surface, in four bore holes, and in a 125 m ice tunnel. A band of fine bubbly white ice with a single maximum fabric appears at the glacier surface about 160 m from the margin. This ba...
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Language: | English |
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Cambridge University Press (CUP)
1973
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Online Access: | http://dx.doi.org/10.1017/s0022143000031841 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031841 |
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crcambridgeupr:10.1017/s0022143000031841 2024-09-15T17:57:05+00:00 Structure and Flow in the Margin of the Barnes Ice Cap, Baffin Island, N.W.T., Canada Hooke, Roger Leb. 1973 http://dx.doi.org/10.1017/s0022143000031841 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031841 en eng Cambridge University Press (CUP) Journal of Glaciology volume 12, issue 66, page 423-438 ISSN 0022-1430 1727-5652 journal-article 1973 crcambridgeupr https://doi.org/10.1017/s0022143000031841 2024-07-31T04:03:43Z The structure and flow field in the margin of the Barnes Ice Cap was determined through observations on the ice-cap surface, in four bore holes, and in a 125 m ice tunnel. A band of fine bubbly white ice with a single maximum fabric appears at the glacier surface about 160 m from the margin. This band is overlain by coarse blue ice with a four-maximum fabric, and underlain by alternating bands of fine ice with a single-maximum fabric and moderately coarse ice with a two or three-maximum fabric. The effective strain rate was determined from the bore-hole and tunnel deformation data, and possible variations in the other three parameters in Glen’s flow law, , were studied. It appears that τ xy is independent of depth near the surface, and that relative to the coarse blue ice, A is 40 to 50% lower in the white ice and possibly 10% lower in the fine blue ice. Dips of foliation planes decrease rapidly with increasing depth and distance from the margin. This foliation is assumed to have developed near and parallel to the bed some distance from the margin. An analysis based on this assumption predicts the observed change in dip, but suggests that it did not develop under the present flow field. The ice cap was probably thicker a few tens of years ago, and the observed foliation pattern may be a relict from that time. Article in Journal/Newspaper Baffin Island Baffin Barnes Ice Cap glacier* Ice cap Journal of Glaciology Cambridge University Press Journal of Glaciology 12 66 423 438 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
The structure and flow field in the margin of the Barnes Ice Cap was determined through observations on the ice-cap surface, in four bore holes, and in a 125 m ice tunnel. A band of fine bubbly white ice with a single maximum fabric appears at the glacier surface about 160 m from the margin. This band is overlain by coarse blue ice with a four-maximum fabric, and underlain by alternating bands of fine ice with a single-maximum fabric and moderately coarse ice with a two or three-maximum fabric. The effective strain rate was determined from the bore-hole and tunnel deformation data, and possible variations in the other three parameters in Glen’s flow law, , were studied. It appears that τ xy is independent of depth near the surface, and that relative to the coarse blue ice, A is 40 to 50% lower in the white ice and possibly 10% lower in the fine blue ice. Dips of foliation planes decrease rapidly with increasing depth and distance from the margin. This foliation is assumed to have developed near and parallel to the bed some distance from the margin. An analysis based on this assumption predicts the observed change in dip, but suggests that it did not develop under the present flow field. The ice cap was probably thicker a few tens of years ago, and the observed foliation pattern may be a relict from that time. |
format |
Article in Journal/Newspaper |
author |
Hooke, Roger Leb. |
spellingShingle |
Hooke, Roger Leb. Structure and Flow in the Margin of the Barnes Ice Cap, Baffin Island, N.W.T., Canada |
author_facet |
Hooke, Roger Leb. |
author_sort |
Hooke, Roger Leb. |
title |
Structure and Flow in the Margin of the Barnes Ice Cap, Baffin Island, N.W.T., Canada |
title_short |
Structure and Flow in the Margin of the Barnes Ice Cap, Baffin Island, N.W.T., Canada |
title_full |
Structure and Flow in the Margin of the Barnes Ice Cap, Baffin Island, N.W.T., Canada |
title_fullStr |
Structure and Flow in the Margin of the Barnes Ice Cap, Baffin Island, N.W.T., Canada |
title_full_unstemmed |
Structure and Flow in the Margin of the Barnes Ice Cap, Baffin Island, N.W.T., Canada |
title_sort |
structure and flow in the margin of the barnes ice cap, baffin island, n.w.t., canada |
publisher |
Cambridge University Press (CUP) |
publishDate |
1973 |
url |
http://dx.doi.org/10.1017/s0022143000031841 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031841 |
genre |
Baffin Island Baffin Barnes Ice Cap glacier* Ice cap Journal of Glaciology |
genre_facet |
Baffin Island Baffin Barnes Ice Cap glacier* Ice cap Journal of Glaciology |
op_source |
Journal of Glaciology volume 12, issue 66, page 423-438 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000031841 |
container_title |
Journal of Glaciology |
container_volume |
12 |
container_issue |
66 |
container_start_page |
423 |
op_container_end_page |
438 |
_version_ |
1810433275583266816 |