A process-based approach to estimate point snow instability
Snow instability data provide information about the mechanical state of the snow cover and are essential for forecasting snow avalanches. So far, direct observations of instability (recent avalanches, shooting cracks or whumpf sounds) are complemented with field tests such as the rutschblock test, s...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:b8a724abaf4c46008cf9adddb258adc6 2023-05-15T18:32:22+02:00 A process-based approach to estimate point snow instability B. Reuter J. Schweizer A. van Herwijnen 2015-05-01 https://doi.org/10.5194/tc-9-837-2015 http://www.the-cryosphere.net/9/837/2015/tc-9-837-2015.pdf https://doaj.org/article/b8a724abaf4c46008cf9adddb258adc6 en eng Copernicus Publications 1994-0416 1994-0424 doi:10.5194/tc-9-837-2015 http://www.the-cryosphere.net/9/837/2015/tc-9-837-2015.pdf https://doaj.org/article/b8a724abaf4c46008cf9adddb258adc6 undefined The Cryosphere, Vol 9, Iss 3, Pp 837-847 (2015) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2015 fttriple https://doi.org/10.5194/tc-9-837-2015 2023-01-22T19:33:51Z Snow instability data provide information about the mechanical state of the snow cover and are essential for forecasting snow avalanches. So far, direct observations of instability (recent avalanches, shooting cracks or whumpf sounds) are complemented with field tests such as the rutschblock test, since no measurement method for instability exists. We propose a new approach based on snow mechanical properties derived from the snow micro-penetrometer that takes into account the two essential processes during dry-snow avalanche release: failure initiation and crack propagation. To estimate the propensity of failure initiation we define a stress-based failure criterion, whereas the propensity of crack propagation is described by the critical cut length as obtained with a propagation saw test. The input parameters include layer thickness, snow density, effective elastic modulus, strength and specific fracture energy of the weak layer – all derived from the penetration-force signal acquired with the snow micro-penetrometer. Both instability measures were validated with independent field data and correlated well with results from field tests. Comparisons with observed signs of instability clearly indicated that a snowpack is only prone to avalanche if the two separate conditions for failure initiation and crack propagation are fulfilled. To our knowledge, this is the first time that an objective method for estimating snow instability has been proposed. The approach can either be used directly based on field measurements with the snow micro-penetrometer, or be implemented in numerical snow cover models. With an objective measure of instability at hand, the problem of spatial variations of instability and its causes can now be tackled. Article in Journal/Newspaper The Cryosphere Unknown The Cryosphere 9 3 837 847 |
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Open Polar |
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English |
topic |
envir geo |
spellingShingle |
envir geo B. Reuter J. Schweizer A. van Herwijnen A process-based approach to estimate point snow instability |
topic_facet |
envir geo |
description |
Snow instability data provide information about the mechanical state of the snow cover and are essential for forecasting snow avalanches. So far, direct observations of instability (recent avalanches, shooting cracks or whumpf sounds) are complemented with field tests such as the rutschblock test, since no measurement method for instability exists. We propose a new approach based on snow mechanical properties derived from the snow micro-penetrometer that takes into account the two essential processes during dry-snow avalanche release: failure initiation and crack propagation. To estimate the propensity of failure initiation we define a stress-based failure criterion, whereas the propensity of crack propagation is described by the critical cut length as obtained with a propagation saw test. The input parameters include layer thickness, snow density, effective elastic modulus, strength and specific fracture energy of the weak layer – all derived from the penetration-force signal acquired with the snow micro-penetrometer. Both instability measures were validated with independent field data and correlated well with results from field tests. Comparisons with observed signs of instability clearly indicated that a snowpack is only prone to avalanche if the two separate conditions for failure initiation and crack propagation are fulfilled. To our knowledge, this is the first time that an objective method for estimating snow instability has been proposed. The approach can either be used directly based on field measurements with the snow micro-penetrometer, or be implemented in numerical snow cover models. With an objective measure of instability at hand, the problem of spatial variations of instability and its causes can now be tackled. |
format |
Article in Journal/Newspaper |
author |
B. Reuter J. Schweizer A. van Herwijnen |
author_facet |
B. Reuter J. Schweizer A. van Herwijnen |
author_sort |
B. Reuter |
title |
A process-based approach to estimate point snow instability |
title_short |
A process-based approach to estimate point snow instability |
title_full |
A process-based approach to estimate point snow instability |
title_fullStr |
A process-based approach to estimate point snow instability |
title_full_unstemmed |
A process-based approach to estimate point snow instability |
title_sort |
process-based approach to estimate point snow instability |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/tc-9-837-2015 http://www.the-cryosphere.net/9/837/2015/tc-9-837-2015.pdf https://doaj.org/article/b8a724abaf4c46008cf9adddb258adc6 |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 9, Iss 3, Pp 837-847 (2015) |
op_relation |
1994-0416 1994-0424 doi:10.5194/tc-9-837-2015 http://www.the-cryosphere.net/9/837/2015/tc-9-837-2015.pdf https://doaj.org/article/b8a724abaf4c46008cf9adddb258adc6 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-9-837-2015 |
container_title |
The Cryosphere |
container_volume |
9 |
container_issue |
3 |
container_start_page |
837 |
op_container_end_page |
847 |
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1766216469086994432 |