Hydraulics of Subglacial Cavities
Abstract A theoretical model is developed to describe the steady-state behavior of interconnected, water-filled cavities at the glacier bed. Physically plausible cavities should contain constrictions along the flow path, with flow in the wider sections being relatively sluggish. Mean flow rates in c...
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Cambridge University Press (CUP)
1986
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Online Access: | http://dx.doi.org/10.1017/s0022143000012156 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000012156 |
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crcambridgeupr:10.1017/s0022143000012156 2024-09-15T18:15:39+00:00 Hydraulics of Subglacial Cavities Walder, Joseph S. 1986 http://dx.doi.org/10.1017/s0022143000012156 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000012156 en eng Cambridge University Press (CUP) Journal of Glaciology volume 32, issue 112, page 439-445 ISSN 0022-1430 1727-5652 journal-article 1986 crcambridgeupr https://doi.org/10.1017/s0022143000012156 2024-07-17T04:03:28Z Abstract A theoretical model is developed to describe the steady-state behavior of interconnected, water-filled cavities at the glacier bed. Physically plausible cavities should contain constrictions along the flow path, with flow in the wider sections being relatively sluggish. Mean flow rates in cavities may be at least one order of magnitude less than in channels incised into the basal ice (R channels). Melting due to viscous dissipation - the process that allows R channels to exist - probably plays a minor or negligible role, as compared to glacier sliding, in determining the size of cavities. Furthermore, a system of subglacial cavities should not show a tendency for localization of flow in a few main conduits, as does an R-channel system. If water pressure rises to within several bars of overburden pressure, the rate of cavity closure by creep falls below the rate of cavity opening by sliding and melting, with cavities then becoming unstable. Subsequent evolution of the drainage system should depend upon the total melt-water flux. Circumstances may arise in which cavities and channels act as conduits for melt water; such a configuration would probably show unusual transient behavior. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 32 112 439 445 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract A theoretical model is developed to describe the steady-state behavior of interconnected, water-filled cavities at the glacier bed. Physically plausible cavities should contain constrictions along the flow path, with flow in the wider sections being relatively sluggish. Mean flow rates in cavities may be at least one order of magnitude less than in channels incised into the basal ice (R channels). Melting due to viscous dissipation - the process that allows R channels to exist - probably plays a minor or negligible role, as compared to glacier sliding, in determining the size of cavities. Furthermore, a system of subglacial cavities should not show a tendency for localization of flow in a few main conduits, as does an R-channel system. If water pressure rises to within several bars of overburden pressure, the rate of cavity closure by creep falls below the rate of cavity opening by sliding and melting, with cavities then becoming unstable. Subsequent evolution of the drainage system should depend upon the total melt-water flux. Circumstances may arise in which cavities and channels act as conduits for melt water; such a configuration would probably show unusual transient behavior. |
format |
Article in Journal/Newspaper |
author |
Walder, Joseph S. |
spellingShingle |
Walder, Joseph S. Hydraulics of Subglacial Cavities |
author_facet |
Walder, Joseph S. |
author_sort |
Walder, Joseph S. |
title |
Hydraulics of Subglacial Cavities |
title_short |
Hydraulics of Subglacial Cavities |
title_full |
Hydraulics of Subglacial Cavities |
title_fullStr |
Hydraulics of Subglacial Cavities |
title_full_unstemmed |
Hydraulics of Subglacial Cavities |
title_sort |
hydraulics of subglacial cavities |
publisher |
Cambridge University Press (CUP) |
publishDate |
1986 |
url |
http://dx.doi.org/10.1017/s0022143000012156 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000012156 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 32, issue 112, page 439-445 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000012156 |
container_title |
Journal of Glaciology |
container_volume |
32 |
container_issue |
112 |
container_start_page |
439 |
op_container_end_page |
445 |
_version_ |
1810453559177641984 |