Modifications to the Theory of Intraglacial Waterways for the Case of Subglacial Ones
Abstract It is argued that in temperate mountain glaciers, waterways are subglacial. It is shown that the theory of Spring and Hutter (1981) for intraglacial flooded conduits leads to an equation for the grade line which differs from Röthlisberger’s (1972) only by negligible terms, and a slight modi...
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Cambridge University Press (CUP)
1983
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Online Access: | http://dx.doi.org/10.1017/s0022143000008273 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000008273 |
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crcambridgeupr:10.1017/s0022143000008273 2024-03-03T08:46:03+00:00 Modifications to the Theory of Intraglacial Waterways for the Case of Subglacial Ones Lliboutry, Louis 1983 http://dx.doi.org/10.1017/s0022143000008273 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000008273 en eng Cambridge University Press (CUP) Journal of Glaciology volume 29, issue 102, page 216-226 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1983 crcambridgeupr https://doi.org/10.1017/s0022143000008273 2024-02-08T08:40:23Z Abstract It is argued that in temperate mountain glaciers, waterways are subglacial. It is shown that the theory of Spring and Hutter (1981) for intraglacial flooded conduits leads to an equation for the grade line which differs from Röthlisberger’s (1972) only by negligible terms, and a slight modification of the exponent of the discharge. For a subglacial flooded waterway two important processes should instead be introduced: the enhancement of plastic deformation on the up-stream side of bumps, and the heat afforded by ground water (which in winter accounts for most of the discharge). The theory modified in this way explains why Röthlisberger had to adopt an unrealistic value for the rheological parameter of ice. It leads to the conclusion that in areas which are not overdeepened, most of the year subglacial waterways should remain not flooded and at atmospheric pressure. The case of overdeepening is examined. Finally the implications of this new model for glacier sliding theory are demonstrated. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 29 102 216 226 |
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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 Lliboutry, Louis Modifications to the Theory of Intraglacial Waterways for the Case of Subglacial Ones |
topic_facet |
Earth-Surface Processes |
description |
Abstract It is argued that in temperate mountain glaciers, waterways are subglacial. It is shown that the theory of Spring and Hutter (1981) for intraglacial flooded conduits leads to an equation for the grade line which differs from Röthlisberger’s (1972) only by negligible terms, and a slight modification of the exponent of the discharge. For a subglacial flooded waterway two important processes should instead be introduced: the enhancement of plastic deformation on the up-stream side of bumps, and the heat afforded by ground water (which in winter accounts for most of the discharge). The theory modified in this way explains why Röthlisberger had to adopt an unrealistic value for the rheological parameter of ice. It leads to the conclusion that in areas which are not overdeepened, most of the year subglacial waterways should remain not flooded and at atmospheric pressure. The case of overdeepening is examined. Finally the implications of this new model for glacier sliding theory are demonstrated. |
format |
Article in Journal/Newspaper |
author |
Lliboutry, Louis |
author_facet |
Lliboutry, Louis |
author_sort |
Lliboutry, Louis |
title |
Modifications to the Theory of Intraglacial Waterways for the Case of Subglacial Ones |
title_short |
Modifications to the Theory of Intraglacial Waterways for the Case of Subglacial Ones |
title_full |
Modifications to the Theory of Intraglacial Waterways for the Case of Subglacial Ones |
title_fullStr |
Modifications to the Theory of Intraglacial Waterways for the Case of Subglacial Ones |
title_full_unstemmed |
Modifications to the Theory of Intraglacial Waterways for the Case of Subglacial Ones |
title_sort |
modifications to the theory of intraglacial waterways for the case of subglacial ones |
publisher |
Cambridge University Press (CUP) |
publishDate |
1983 |
url |
http://dx.doi.org/10.1017/s0022143000008273 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000008273 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 29, issue 102, page 216-226 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000008273 |
container_title |
Journal of Glaciology |
container_volume |
29 |
container_issue |
102 |
container_start_page |
216 |
op_container_end_page |
226 |
_version_ |
1792501893410324480 |