Basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock
Abstract The flow field of a medium sliding without friction over a strongly undulating surface is calculated numerically. The results are used to elucidate the basal-flow characteristics of glacier flow and they are discussed with reference to known analytical solutions. Extrusion flow is found to...
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Language: | English |
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Cambridge University Press (CUP)
1997
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Online Access: | http://dx.doi.org/10.1017/s0022143000002835 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002835 |
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crcambridgeupr:10.1017/s0022143000002835 2024-05-19T07:43:13+00:00 Basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock Gudmundsson, G. Hilmar 1997 http://dx.doi.org/10.1017/s0022143000002835 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002835 en eng Cambridge University Press (CUP) Journal of Glaciology volume 43, issue 143, page 80-89 ISSN 0022-1430 1727-5652 journal-article 1997 crcambridgeupr https://doi.org/10.1017/s0022143000002835 2024-05-02T06:51:00Z Abstract The flow field of a medium sliding without friction over a strongly undulating surface is calculated numerically. The results are used to elucidate the basal-flow characteristics of glacier flow and they are discussed with reference to known analytical solutions. Extrusion flow is found to become increasingly pronounced as the value of n, where n is a parameter in Glen’s flow law, becomes larger. For sinusoidal bedrock undulations, a flow separation occurs if the amplitude-to-wavelength ratio exceeds a critical value of about 0.28. The main flow then sets up a secondary flow circulation within the trough, and the ice participating in this circular motion theoretically never leaves it. The sliding velocity is calculated numerically as a function of the mean basal shear stress, the amplitude-to-wavelength ratio and the flow parameter n. For moderate and high slope fluctuations, the sliding velocity is significantly different from what would be expected from results based on the small-slope approximation. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 43 143 80 89 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract The flow field of a medium sliding without friction over a strongly undulating surface is calculated numerically. The results are used to elucidate the basal-flow characteristics of glacier flow and they are discussed with reference to known analytical solutions. Extrusion flow is found to become increasingly pronounced as the value of n, where n is a parameter in Glen’s flow law, becomes larger. For sinusoidal bedrock undulations, a flow separation occurs if the amplitude-to-wavelength ratio exceeds a critical value of about 0.28. The main flow then sets up a secondary flow circulation within the trough, and the ice participating in this circular motion theoretically never leaves it. The sliding velocity is calculated numerically as a function of the mean basal shear stress, the amplitude-to-wavelength ratio and the flow parameter n. For moderate and high slope fluctuations, the sliding velocity is significantly different from what would be expected from results based on the small-slope approximation. |
format |
Article in Journal/Newspaper |
author |
Gudmundsson, G. Hilmar |
spellingShingle |
Gudmundsson, G. Hilmar Basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock |
author_facet |
Gudmundsson, G. Hilmar |
author_sort |
Gudmundsson, G. Hilmar |
title |
Basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock |
title_short |
Basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock |
title_full |
Basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock |
title_fullStr |
Basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock |
title_full_unstemmed |
Basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock |
title_sort |
basal-flow characteristics of a non-linear flow sliding frictionless over strongly undulating bedrock |
publisher |
Cambridge University Press (CUP) |
publishDate |
1997 |
url |
http://dx.doi.org/10.1017/s0022143000002835 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002835 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 43, issue 143, page 80-89 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000002835 |
container_title |
Journal of Glaciology |
container_volume |
43 |
container_issue |
143 |
container_start_page |
80 |
op_container_end_page |
89 |
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1799482935056793600 |