Empirical Studies of Ice Sliding
Abstract An experimental programme has been carried out for studying temperate-ice sliding over rock surfaces with a wide range of roughnesses, for normal and shear stresses comparable to those expected under real ice masses. The limiting static shear stress for acceleration has been found to be dir...
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Language: | English |
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Cambridge University Press (CUP)
1979
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Online Access: | http://dx.doi.org/10.1017/s0022143000029804 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000029804 |
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crcambridgeupr:10.1017/s0022143000029804 2024-04-07T07:53:41+00:00 Empirical Studies of Ice Sliding Budd, W. F. Keage, P. L. Blundy, N. A. 1979 http://dx.doi.org/10.1017/s0022143000029804 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000029804 en eng Cambridge University Press (CUP) Journal of Glaciology volume 23, issue 89, page 157-170 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1979 crcambridgeupr https://doi.org/10.1017/s0022143000029804 2024-03-08T00:35:19Z Abstract An experimental programme has been carried out for studying temperate-ice sliding over rock surfaces with a wide range of roughnesses, for normal and shear stresses comparable to those expected under real ice masses. The limiting static shear stress for acceleration has been found to be directly proportional to the normal load giving a constant limiting coefficient of static friction characteristic of the surface. For a constant applied normal stress N and shear stress τ b , well below the limiting static shear, a steady velocity V b results which increases approximately proportionally to τ b and decreases with increasing N and the roughness of the surface. For high normal stress the velocity becomes approximately proportional to the shear stress cubed and inversely proportional to the normal stress. As the shear stress increases acceleration sets in, which, for different roughness and normal loads, tends to occur for a constant value of the product τ b V b . For some surfaces at high normal loads this acceleration was retarded by erosion. For constant-applied-velocity tests a steady shear stress resulted, which tended to become constant with high velocities, and which increased with increasing normal stress but with a reduced coefficient of sliding friction. The relevance of the results to the sliding of real ice masses is discussed with particular reference to the importance of the effect of the relative normal stress, above basal water pressure, to the sliding rate. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 23 89 157 170 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Budd, W. F. Keage, P. L. Blundy, N. A. Empirical Studies of Ice Sliding |
topic_facet |
Earth-Surface Processes |
description |
Abstract An experimental programme has been carried out for studying temperate-ice sliding over rock surfaces with a wide range of roughnesses, for normal and shear stresses comparable to those expected under real ice masses. The limiting static shear stress for acceleration has been found to be directly proportional to the normal load giving a constant limiting coefficient of static friction characteristic of the surface. For a constant applied normal stress N and shear stress τ b , well below the limiting static shear, a steady velocity V b results which increases approximately proportionally to τ b and decreases with increasing N and the roughness of the surface. For high normal stress the velocity becomes approximately proportional to the shear stress cubed and inversely proportional to the normal stress. As the shear stress increases acceleration sets in, which, for different roughness and normal loads, tends to occur for a constant value of the product τ b V b . For some surfaces at high normal loads this acceleration was retarded by erosion. For constant-applied-velocity tests a steady shear stress resulted, which tended to become constant with high velocities, and which increased with increasing normal stress but with a reduced coefficient of sliding friction. The relevance of the results to the sliding of real ice masses is discussed with particular reference to the importance of the effect of the relative normal stress, above basal water pressure, to the sliding rate. |
format |
Article in Journal/Newspaper |
author |
Budd, W. F. Keage, P. L. Blundy, N. A. |
author_facet |
Budd, W. F. Keage, P. L. Blundy, N. A. |
author_sort |
Budd, W. F. |
title |
Empirical Studies of Ice Sliding |
title_short |
Empirical Studies of Ice Sliding |
title_full |
Empirical Studies of Ice Sliding |
title_fullStr |
Empirical Studies of Ice Sliding |
title_full_unstemmed |
Empirical Studies of Ice Sliding |
title_sort |
empirical studies of ice sliding |
publisher |
Cambridge University Press (CUP) |
publishDate |
1979 |
url |
http://dx.doi.org/10.1017/s0022143000029804 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000029804 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 23, issue 89, page 157-170 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000029804 |
container_title |
Journal of Glaciology |
container_volume |
23 |
container_issue |
89 |
container_start_page |
157 |
op_container_end_page |
170 |
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1795669766971588608 |