Stress and velocity fields in glaciers: Part II. Sliding and basal stress distribution
Abstract Numerical methods are used to examine the interaction between the spatial distribution of the basal shear traction and the corresponding basal velocity for an inclined slab geometry. In our improved treatment, we reject the common assumption that basal velocity is a simple function of local...
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Language: | English |
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Cambridge University Press (CUP)
1998
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crcambridgeupr:10.1017/s0022143000001970 2024-03-03T08:46:01+00:00 Stress and velocity fields in glaciers: Part II. Sliding and basal stress distribution Blatter, Heinz Clarke, Garry K. C. Colinge, Jacques 1998 http://dx.doi.org/10.1017/s0022143000001970 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000001970 en eng Cambridge University Press (CUP) Journal of Glaciology volume 44, issue 148, page 457-466 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1998 crcambridgeupr https://doi.org/10.1017/s0022143000001970 2024-02-08T08:38:15Z Abstract Numerical methods are used to examine the interaction between the spatial distribution of the basal shear traction and the corresponding basal velocity for an inclined slab geometry. In our improved treatment, we reject the common assumption that basal velocity is a simple function of local variables in favour of a non-local treatment that includes normal deviatoric stress and takes basal velocity to be an integrated response to spatially varying influences. Computationally, one must either iterate the basal velocity with a friction parameterization that relates basal shear traction to basal velocity or, alternatively, prescribe the basal shear traction that results from bed decoupling and substrate déformation. The average of basal shear traction over the entire bed of the ice mass is invariant under changes in sliding distribution and thus constitutes a useful reference; any local relative reduction of traction leads to basal movement, either sliding over the bed or moving with a deforming subglacial layer. The local stress réduction is accompanied by a concentration of traction up-and down-glacier of the moving base. Growth, decay and possible migration of basal stress concentrations may be closely related to short-lived sliding events and to surges. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 44 148 457 466 |
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Open Polar |
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Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Blatter, Heinz Clarke, Garry K. C. Colinge, Jacques Stress and velocity fields in glaciers: Part II. Sliding and basal stress distribution |
topic_facet |
Earth-Surface Processes |
description |
Abstract Numerical methods are used to examine the interaction between the spatial distribution of the basal shear traction and the corresponding basal velocity for an inclined slab geometry. In our improved treatment, we reject the common assumption that basal velocity is a simple function of local variables in favour of a non-local treatment that includes normal deviatoric stress and takes basal velocity to be an integrated response to spatially varying influences. Computationally, one must either iterate the basal velocity with a friction parameterization that relates basal shear traction to basal velocity or, alternatively, prescribe the basal shear traction that results from bed decoupling and substrate déformation. The average of basal shear traction over the entire bed of the ice mass is invariant under changes in sliding distribution and thus constitutes a useful reference; any local relative reduction of traction leads to basal movement, either sliding over the bed or moving with a deforming subglacial layer. The local stress réduction is accompanied by a concentration of traction up-and down-glacier of the moving base. Growth, decay and possible migration of basal stress concentrations may be closely related to short-lived sliding events and to surges. |
format |
Article in Journal/Newspaper |
author |
Blatter, Heinz Clarke, Garry K. C. Colinge, Jacques |
author_facet |
Blatter, Heinz Clarke, Garry K. C. Colinge, Jacques |
author_sort |
Blatter, Heinz |
title |
Stress and velocity fields in glaciers: Part II. Sliding and basal stress distribution |
title_short |
Stress and velocity fields in glaciers: Part II. Sliding and basal stress distribution |
title_full |
Stress and velocity fields in glaciers: Part II. Sliding and basal stress distribution |
title_fullStr |
Stress and velocity fields in glaciers: Part II. Sliding and basal stress distribution |
title_full_unstemmed |
Stress and velocity fields in glaciers: Part II. Sliding and basal stress distribution |
title_sort |
stress and velocity fields in glaciers: part ii. sliding and basal stress distribution |
publisher |
Cambridge University Press (CUP) |
publishDate |
1998 |
url |
http://dx.doi.org/10.1017/s0022143000001970 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000001970 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 44, issue 148, page 457-466 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000001970 |
container_title |
Journal of Glaciology |
container_volume |
44 |
container_issue |
148 |
container_start_page |
457 |
op_container_end_page |
466 |
_version_ |
1792501833418145792 |