Glacier Sliding Down an Inclined Wavy Bed With Friction
The effects of frictional tangential traction combined with regelation on the basal sliding of a temperate glacier down an inclined wavy bed are examined. Two friction models are treated. First, a Coulomb law model having the assumptions that sliding occurs everywhere and that the tangential tractio...
Published in: | Journal of Glaciology |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press (CUP)
1976
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1017/s0022143000013745 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000013745 |
id |
crcambridgeupr:10.1017/s0022143000013745 |
---|---|
record_format |
openpolar |
spelling |
crcambridgeupr:10.1017/s0022143000013745 2024-09-09T19:49:02+00:00 Glacier Sliding Down an Inclined Wavy Bed With Friction Morland, L. W. 1976 http://dx.doi.org/10.1017/s0022143000013745 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000013745 en eng Cambridge University Press (CUP) Journal of Glaciology volume 17, issue 77, page 463-477 ISSN 0022-1430 1727-5652 journal-article 1976 crcambridgeupr https://doi.org/10.1017/s0022143000013745 2024-07-17T04:04:04Z The effects of frictional tangential traction combined with regelation on the basal sliding of a temperate glacier down an inclined wavy bed are examined. Two friction models are treated. First, a Coulomb law model having the assumptions that sliding occurs everywhere and that the tangential traction is proportional to the normal pressure. Secondly, a velocity power law in which the tangential traction is proportional to a power of the slip velocity. The ice motion is approximated by steady slow Newtonian flow and the bed undulation about a mean bed-line has a maximum slope ∊ ≪I. Flow solutions are constructed as perturbations (in powers off ∈) of the plane laminar flow corresponding to non-slip on the mean bed-line assuming that the ice remains everywhere in contact with the bed; that is, no cavitation takes place. If the normal traction is predicted to be tensile over part of the bed, implying that cavitation has occurred, then a new solution is needed in which the ice base over cavities is traction-free. Since the cavity sections and profile of the free ice base are then part of the overall solution, an intricate mixed boundary-value problem is set up for the flow and the present analysis is inadequate. For a sinusoidal bed the perfect-slip (zero tangential traction) solution predicts compressive normal traction everywhere on the bed provided that the mean bed-line inclination α (to the horizontal) is less than a critical value α e which is of order ε. For greater values of α including a range of order ∊, the normal traction is tensile on some parts of the bed, and a solution with cavitation is needed. If the tensile sections are relatively small it is expected that the resulting cavitation will not change the overall solution significantly. However, the Coulomb friction solution has extensive zones of tensile traction for all values of α, so that extensive cavitation would occur. In contrast, the velocity-power friction solution has compressive traction everywhere on the bed for α ⩽α e = 0 (I) provided that ... Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 17 77 463 477 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
The effects of frictional tangential traction combined with regelation on the basal sliding of a temperate glacier down an inclined wavy bed are examined. Two friction models are treated. First, a Coulomb law model having the assumptions that sliding occurs everywhere and that the tangential traction is proportional to the normal pressure. Secondly, a velocity power law in which the tangential traction is proportional to a power of the slip velocity. The ice motion is approximated by steady slow Newtonian flow and the bed undulation about a mean bed-line has a maximum slope ∊ ≪I. Flow solutions are constructed as perturbations (in powers off ∈) of the plane laminar flow corresponding to non-slip on the mean bed-line assuming that the ice remains everywhere in contact with the bed; that is, no cavitation takes place. If the normal traction is predicted to be tensile over part of the bed, implying that cavitation has occurred, then a new solution is needed in which the ice base over cavities is traction-free. Since the cavity sections and profile of the free ice base are then part of the overall solution, an intricate mixed boundary-value problem is set up for the flow and the present analysis is inadequate. For a sinusoidal bed the perfect-slip (zero tangential traction) solution predicts compressive normal traction everywhere on the bed provided that the mean bed-line inclination α (to the horizontal) is less than a critical value α e which is of order ε. For greater values of α including a range of order ∊, the normal traction is tensile on some parts of the bed, and a solution with cavitation is needed. If the tensile sections are relatively small it is expected that the resulting cavitation will not change the overall solution significantly. However, the Coulomb friction solution has extensive zones of tensile traction for all values of α, so that extensive cavitation would occur. In contrast, the velocity-power friction solution has compressive traction everywhere on the bed for α ⩽α e = 0 (I) provided that ... |
format |
Article in Journal/Newspaper |
author |
Morland, L. W. |
spellingShingle |
Morland, L. W. Glacier Sliding Down an Inclined Wavy Bed With Friction |
author_facet |
Morland, L. W. |
author_sort |
Morland, L. W. |
title |
Glacier Sliding Down an Inclined Wavy Bed With Friction |
title_short |
Glacier Sliding Down an Inclined Wavy Bed With Friction |
title_full |
Glacier Sliding Down an Inclined Wavy Bed With Friction |
title_fullStr |
Glacier Sliding Down an Inclined Wavy Bed With Friction |
title_full_unstemmed |
Glacier Sliding Down an Inclined Wavy Bed With Friction |
title_sort |
glacier sliding down an inclined wavy bed with friction |
publisher |
Cambridge University Press (CUP) |
publishDate |
1976 |
url |
http://dx.doi.org/10.1017/s0022143000013745 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000013745 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 17, issue 77, page 463-477 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000013745 |
container_title |
Journal of Glaciology |
container_volume |
17 |
container_issue |
77 |
container_start_page |
463 |
op_container_end_page |
477 |
_version_ |
1809918412887949312 |