Pressure-Melting Effects in Basal Ice of Temperate Glaciers: Laboratory Studies and Field Observations Under Glacier D’Argentière
Abstract The suggestion that patches of basal ice may freeze to the bed of a glacier due to certain regelation effects has been tested in the laboratory by applying high hydrostatic pressures to ice samples at the pressure-melting point. During compression, ice temperatures follow the pressure-melti...
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Language: | English |
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Cambridge University Press (CUP)
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Online Access: | http://dx.doi.org/10.1017/s0022143000029889 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000029889 |
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crcambridgeupr:10.1017/s0022143000029889 2024-04-07T07:53:41+00:00 Pressure-Melting Effects in Basal Ice of Temperate Glaciers: Laboratory Studies and Field Observations Under Glacier D’Argentière Goodman, D. J. King, G. C. P. Millar, D. H. M. Robin, G. de Q. 1979 http://dx.doi.org/10.1017/s0022143000029889 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000029889 en eng Cambridge University Press (CUP) Journal of Glaciology volume 23, issue 89, page 259-271 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1979 crcambridgeupr https://doi.org/10.1017/s0022143000029889 2024-03-08T00:35:31Z Abstract The suggestion that patches of basal ice may freeze to the bed of a glacier due to certain regelation effects has been tested in the laboratory by applying high hydrostatic pressures to ice samples at the pressure-melting point. During compression, ice temperatures follow the pressure-melting point closely, but after rapid decompression the ice temperature at first returns only half to three-quarters of the way to the pressure-melting point, after which it appears to warm by thermal conduction from outside the ice sample. If the moving ice at the base of a glacier behaves in the same way as it is exposed to changing pressure fields, frozen patches at bedrock are to be expected. Records of strain variations in a tunnel beneath Glacier d’Argentière show two types of strain events. The first is a rapid jump or offset in the recorded strain, while the second are strain excursions, initiated by a change in strain over a period up to ten seconds, followed by a gradual recovery to the original strain over some minutes. It is suggested that the offset events are due to nearby stress release due to fracturing of frozen patches of ice at the bedrock while the strain-excursion events show the more distant adjustment of the glacial bed to the former events due to the time lags associated with changes of water-film thickness and regelation heat flow. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 23 89 259 271 |
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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 Goodman, D. J. King, G. C. P. Millar, D. H. M. Robin, G. de Q. Pressure-Melting Effects in Basal Ice of Temperate Glaciers: Laboratory Studies and Field Observations Under Glacier D’Argentière |
topic_facet |
Earth-Surface Processes |
description |
Abstract The suggestion that patches of basal ice may freeze to the bed of a glacier due to certain regelation effects has been tested in the laboratory by applying high hydrostatic pressures to ice samples at the pressure-melting point. During compression, ice temperatures follow the pressure-melting point closely, but after rapid decompression the ice temperature at first returns only half to three-quarters of the way to the pressure-melting point, after which it appears to warm by thermal conduction from outside the ice sample. If the moving ice at the base of a glacier behaves in the same way as it is exposed to changing pressure fields, frozen patches at bedrock are to be expected. Records of strain variations in a tunnel beneath Glacier d’Argentière show two types of strain events. The first is a rapid jump or offset in the recorded strain, while the second are strain excursions, initiated by a change in strain over a period up to ten seconds, followed by a gradual recovery to the original strain over some minutes. It is suggested that the offset events are due to nearby stress release due to fracturing of frozen patches of ice at the bedrock while the strain-excursion events show the more distant adjustment of the glacial bed to the former events due to the time lags associated with changes of water-film thickness and regelation heat flow. |
format |
Article in Journal/Newspaper |
author |
Goodman, D. J. King, G. C. P. Millar, D. H. M. Robin, G. de Q. |
author_facet |
Goodman, D. J. King, G. C. P. Millar, D. H. M. Robin, G. de Q. |
author_sort |
Goodman, D. J. |
title |
Pressure-Melting Effects in Basal Ice of Temperate Glaciers: Laboratory Studies and Field Observations Under Glacier D’Argentière |
title_short |
Pressure-Melting Effects in Basal Ice of Temperate Glaciers: Laboratory Studies and Field Observations Under Glacier D’Argentière |
title_full |
Pressure-Melting Effects in Basal Ice of Temperate Glaciers: Laboratory Studies and Field Observations Under Glacier D’Argentière |
title_fullStr |
Pressure-Melting Effects in Basal Ice of Temperate Glaciers: Laboratory Studies and Field Observations Under Glacier D’Argentière |
title_full_unstemmed |
Pressure-Melting Effects in Basal Ice of Temperate Glaciers: Laboratory Studies and Field Observations Under Glacier D’Argentière |
title_sort |
pressure-melting effects in basal ice of temperate glaciers: laboratory studies and field observations under glacier d’argentière |
publisher |
Cambridge University Press (CUP) |
publishDate |
1979 |
url |
http://dx.doi.org/10.1017/s0022143000029889 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000029889 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 23, issue 89, page 259-271 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000029889 |
container_title |
Journal of Glaciology |
container_volume |
23 |
container_issue |
89 |
container_start_page |
259 |
op_container_end_page |
271 |
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1795669771083055104 |