气候变化领域集成服务门户(CCPortal): A process-based approach to estimate point snow instability

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DOI	10.5194/tc-9-837-2015
	A process-based approach to estimate point snow instability
	Reuter B.; Schweizer J.; Van Herwijnen A.'
发表日期	2015
ISSN	19940416
卷号	9 期号:3
英文摘要	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. © Author(s) 2015.
学科领域	crack propagation; elastic modulus; instability; penetrometer; snow avalanche; snow cover
语种	英语
scopus关键词	crack propagation; elastic modulus; instability; penetrometer; snow avalanche; snow cover
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119910
作者单位	WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, Davos Dorf, 7260, Switzerland
推荐引用方式 GB/T 7714	Reuter B.,Schweizer J.,Van Herwijnen A.'. A process-based approach to estimate point snow instability[J],2015,9(3).
APA	Reuter B.,Schweizer J.,&Van Herwijnen A.'.(2015).A process-based approach to estimate point snow instability.Cryosphere,9(3).
MLA	Reuter B.,et al."A process-based approach to estimate point snow instability".Cryosphere 9.3(2015).