Snow-Slope Stabili1y – A Probabilistic Approach
Abstract Measurements of snow properties across and down snow slopes have been used to calculate a safety margin — the difference between the basal shear strength and the applied static stress. Areas of basal deficit exist when the applied shear stress exceeds the basal shear strength (the safety ma...
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Language: | English |
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Cambridge University Press (CUP)
1988
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Online Access: | http://dx.doi.org/10.1017/s0022143000032196 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000032196 |
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crcambridgeupr:10.1017/s0022143000032196 2024-03-03T08:46:08+00:00 Snow-Slope Stabili1y – A Probabilistic Approach Conway, H. Abrahamson, J. 1988 http://dx.doi.org/10.1017/s0022143000032196 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000032196 en eng Cambridge University Press (CUP) Journal of Glaciology volume 34, issue 117, page 170-177 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1988 crcambridgeupr https://doi.org/10.1017/s0022143000032196 2024-02-08T08:47:47Z Abstract Measurements of snow properties across and down snow slopes have been used to calculate a safety margin — the difference between the basal shear strength and the applied static stress. Areas of basal deficit exist when the applied shear stress exceeds the basal shear strength (the safety margin is negative), and basal areas are pinned when the safety margin is positive. As the size of deficit increases, stresses within the overlying slab also increase, and these may be sufficient to cause an avalanche. Measurements made on five slopes (four of which had avalanched) were characterized by considerable spatial variability, and the safety margin has been treated as a random function which varies over the slope. Statistical models of Vanmarcke (1977[a], 1983) have been applied to determine the most likely size of deficit required for avalanching (95% confidence). In one case, an avalanche occurred when the length of deficit was only 2.9 m, and in the other cases the length was always less than 7 m. This size of deficit is small compared with the total area of many avalanche slopes which suggests that avalanches initiate from small zones of deficit, and makes it difficult to locate a deficit with just a few tests. The optimum sampling interval and number of tests required to yield an adequate estimate of the statistical parameters of the safety margin are also discussed. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 34 117 170 177 |
institution |
Open Polar |
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Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Conway, H. Abrahamson, J. Snow-Slope Stabili1y – A Probabilistic Approach |
topic_facet |
Earth-Surface Processes |
description |
Abstract Measurements of snow properties across and down snow slopes have been used to calculate a safety margin — the difference between the basal shear strength and the applied static stress. Areas of basal deficit exist when the applied shear stress exceeds the basal shear strength (the safety margin is negative), and basal areas are pinned when the safety margin is positive. As the size of deficit increases, stresses within the overlying slab also increase, and these may be sufficient to cause an avalanche. Measurements made on five slopes (four of which had avalanched) were characterized by considerable spatial variability, and the safety margin has been treated as a random function which varies over the slope. Statistical models of Vanmarcke (1977[a], 1983) have been applied to determine the most likely size of deficit required for avalanching (95% confidence). In one case, an avalanche occurred when the length of deficit was only 2.9 m, and in the other cases the length was always less than 7 m. This size of deficit is small compared with the total area of many avalanche slopes which suggests that avalanches initiate from small zones of deficit, and makes it difficult to locate a deficit with just a few tests. The optimum sampling interval and number of tests required to yield an adequate estimate of the statistical parameters of the safety margin are also discussed. |
format |
Article in Journal/Newspaper |
author |
Conway, H. Abrahamson, J. |
author_facet |
Conway, H. Abrahamson, J. |
author_sort |
Conway, H. |
title |
Snow-Slope Stabili1y – A Probabilistic Approach |
title_short |
Snow-Slope Stabili1y – A Probabilistic Approach |
title_full |
Snow-Slope Stabili1y – A Probabilistic Approach |
title_fullStr |
Snow-Slope Stabili1y – A Probabilistic Approach |
title_full_unstemmed |
Snow-Slope Stabili1y – A Probabilistic Approach |
title_sort |
snow-slope stabili1y – a probabilistic approach |
publisher |
Cambridge University Press (CUP) |
publishDate |
1988 |
url |
http://dx.doi.org/10.1017/s0022143000032196 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000032196 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 34, issue 117, page 170-177 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000032196 |
container_title |
Journal of Glaciology |
container_volume |
34 |
container_issue |
117 |
container_start_page |
170 |
op_container_end_page |
177 |
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1792502062879080448 |