The Uplift of Unteraargletscher at the Beginning of the Melt Season—A Consequence of Water Storage at the Bed?
Abstract Results of systematic movement studies carried out by means of an automatic camera on Unteraargletscher since 1969 are discussed together with supplementary theodolite measurements made at shorter intervals and over a longer section of the glacier. In addition to the typical spring/early su...
Published in: | Journal of Glaciology |
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Language: | English |
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Cambridge University Press (CUP)
1983
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Online Access: | http://dx.doi.org/10.1017/s0022143000005128 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005128 |
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crcambridgeupr:10.1017/s0022143000005128 2024-04-28T08:26:44+00:00 The Uplift of Unteraargletscher at the Beginning of the Melt Season—A Consequence of Water Storage at the Bed? Iken, A. Röthlisberger, H. Flotron, A. Haeberli, W. 1983 http://dx.doi.org/10.1017/s0022143000005128 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005128 en eng Cambridge University Press (CUP) Journal of Glaciology volume 29, issue 101, page 28-47 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1983 crcambridgeupr https://doi.org/10.1017/s0022143000005128 2024-04-09T06:56:19Z Abstract Results of systematic movement studies carried out by means of an automatic camera on Unteraargletscher since 1969 are discussed together with supplementary theodolite measurements made at shorter intervals and over a longer section of the glacier. In addition to the typical spring/early summer maximum of velocity known from other glaciers, an upward movement of up to 0.6 m has been recorded at the beginning of the melt season. It was followed, after a few fluctuations of the vertical velocity, by an equal but slower downward movement which continued at an almost constant rate for about three months. Possible explanations of the uplift are discussed, the most satisfactory explanation being water storage at the bed. The observations then suggest that this storage system is efficiently connected with the main subglacial drainage channels only during times of very high water pressure in the channels. Detailed measurements showed that the times of maximum horizontal velocity coincided with the times of maximum upward velocity rather than with the times when the elevation of the surveyed poles had reached a maximum. On the basis of the hypothesis of water storage at the bed this finding means that the sliding velocity is influenced mainly by the subglacial water pressure and the actual, transient stage of cavity development, while the amount of stored water is of lesser influence. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 29 101 28 47 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Iken, A. Röthlisberger, H. Flotron, A. Haeberli, W. The Uplift of Unteraargletscher at the Beginning of the Melt Season—A Consequence of Water Storage at the Bed? |
topic_facet |
Earth-Surface Processes |
description |
Abstract Results of systematic movement studies carried out by means of an automatic camera on Unteraargletscher since 1969 are discussed together with supplementary theodolite measurements made at shorter intervals and over a longer section of the glacier. In addition to the typical spring/early summer maximum of velocity known from other glaciers, an upward movement of up to 0.6 m has been recorded at the beginning of the melt season. It was followed, after a few fluctuations of the vertical velocity, by an equal but slower downward movement which continued at an almost constant rate for about three months. Possible explanations of the uplift are discussed, the most satisfactory explanation being water storage at the bed. The observations then suggest that this storage system is efficiently connected with the main subglacial drainage channels only during times of very high water pressure in the channels. Detailed measurements showed that the times of maximum horizontal velocity coincided with the times of maximum upward velocity rather than with the times when the elevation of the surveyed poles had reached a maximum. On the basis of the hypothesis of water storage at the bed this finding means that the sliding velocity is influenced mainly by the subglacial water pressure and the actual, transient stage of cavity development, while the amount of stored water is of lesser influence. |
format |
Article in Journal/Newspaper |
author |
Iken, A. Röthlisberger, H. Flotron, A. Haeberli, W. |
author_facet |
Iken, A. Röthlisberger, H. Flotron, A. Haeberli, W. |
author_sort |
Iken, A. |
title |
The Uplift of Unteraargletscher at the Beginning of the Melt Season—A Consequence of Water Storage at the Bed? |
title_short |
The Uplift of Unteraargletscher at the Beginning of the Melt Season—A Consequence of Water Storage at the Bed? |
title_full |
The Uplift of Unteraargletscher at the Beginning of the Melt Season—A Consequence of Water Storage at the Bed? |
title_fullStr |
The Uplift of Unteraargletscher at the Beginning of the Melt Season—A Consequence of Water Storage at the Bed? |
title_full_unstemmed |
The Uplift of Unteraargletscher at the Beginning of the Melt Season—A Consequence of Water Storage at the Bed? |
title_sort |
uplift of unteraargletscher at the beginning of the melt season—a consequence of water storage at the bed? |
publisher |
Cambridge University Press (CUP) |
publishDate |
1983 |
url |
http://dx.doi.org/10.1017/s0022143000005128 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005128 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 29, issue 101, page 28-47 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000005128 |
container_title |
Journal of Glaciology |
container_volume |
29 |
container_issue |
101 |
container_start_page |
28 |
op_container_end_page |
47 |
_version_ |
1797585990540328960 |