Relaxation Self-Oscillations and Processes at the Bottom of Glaciers
Abstract In terms of the theory of oscillations, rapid glacier advances (glacier surges) are relaxation self-oscillation, and large glacier advances of the same character dependent on climate are the result of interaction between forced and self-exciting oscillations. The relation is found between a...
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Language: | English |
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Cambridge University Press (CUP)
1976
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Online Access: | http://dx.doi.org/10.1017/s0022143000031762 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031762 |
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crcambridgeupr:10.1017/s0022143000031762 2024-03-03T08:46:08+00:00 Relaxation Self-Oscillations and Processes at the Bottom of Glaciers Shumskiy, P.A. 1976 http://dx.doi.org/10.1017/s0022143000031762 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031762 en eng Cambridge University Press (CUP) Journal of Glaciology volume 16, issue 74, page 310-311 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1976 crcambridgeupr https://doi.org/10.1017/s0022143000031762 2024-02-08T08:37:11Z Abstract In terms of the theory of oscillations, rapid glacier advances (glacier surges) are relaxation self-oscillation, and large glacier advances of the same character dependent on climate are the result of interaction between forced and self-exciting oscillations. The relation is found between average shear stress and sliding velocity of pure and of moraine-containing ice along the bottom, taking into account the real thermal and kinematic boundary conditions, the different dependence of the ice melting point on hydrostatic pressure and on normal component of the stress deviator, and dry friction against the bottom. In the regime of bottom melting, a communicating system of subglacial drainage channels is formed along (he borders of distal slopes of bottom irregularities. Variations of effective roughness lead to the forced variations of sliding velocity depending on the surface melting rate. Relaxation self-oscillations of glaciers are caused by the alternation of “sticking” to the bottom in the phase of restoration and of rapid sliding along the bottom in the phase of relaxation because of the changes in the concentration of moraine material in the bottom layer of ice and of the force of dry friction against the bottom of a glacier. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 16 74 310 311 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Shumskiy, P.A. Relaxation Self-Oscillations and Processes at the Bottom of Glaciers |
topic_facet |
Earth-Surface Processes |
description |
Abstract In terms of the theory of oscillations, rapid glacier advances (glacier surges) are relaxation self-oscillation, and large glacier advances of the same character dependent on climate are the result of interaction between forced and self-exciting oscillations. The relation is found between average shear stress and sliding velocity of pure and of moraine-containing ice along the bottom, taking into account the real thermal and kinematic boundary conditions, the different dependence of the ice melting point on hydrostatic pressure and on normal component of the stress deviator, and dry friction against the bottom. In the regime of bottom melting, a communicating system of subglacial drainage channels is formed along (he borders of distal slopes of bottom irregularities. Variations of effective roughness lead to the forced variations of sliding velocity depending on the surface melting rate. Relaxation self-oscillations of glaciers are caused by the alternation of “sticking” to the bottom in the phase of restoration and of rapid sliding along the bottom in the phase of relaxation because of the changes in the concentration of moraine material in the bottom layer of ice and of the force of dry friction against the bottom of a glacier. |
format |
Article in Journal/Newspaper |
author |
Shumskiy, P.A. |
author_facet |
Shumskiy, P.A. |
author_sort |
Shumskiy, P.A. |
title |
Relaxation Self-Oscillations and Processes at the Bottom of Glaciers |
title_short |
Relaxation Self-Oscillations and Processes at the Bottom of Glaciers |
title_full |
Relaxation Self-Oscillations and Processes at the Bottom of Glaciers |
title_fullStr |
Relaxation Self-Oscillations and Processes at the Bottom of Glaciers |
title_full_unstemmed |
Relaxation Self-Oscillations and Processes at the Bottom of Glaciers |
title_sort |
relaxation self-oscillations and processes at the bottom of glaciers |
publisher |
Cambridge University Press (CUP) |
publishDate |
1976 |
url |
http://dx.doi.org/10.1017/s0022143000031762 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031762 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 16, issue 74, page 310-311 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000031762 |
container_title |
Journal of Glaciology |
container_volume |
16 |
container_issue |
74 |
container_start_page |
310 |
op_container_end_page |
311 |
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1792502078781784064 |