Item: Interpretation of prevalent avalanche scenarios on the basis of the anticrack model
Title: Interpretation of prevalent avalanche scenarios on the basis of the anticrack model
Proceedings: International Snow Science Workshop, Davos 2009, Proceedings
Authors: Stephan Harvey and Joachim Heierli, WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland. Universität Karlsruhe, Kaiserstr. 76131 Karlsruhe, Germany
Abstract: Each winter the build-up of snow conditions is unique and distinctive, but a wide variety of avalanche situations can be attributed to a relatively small number of typical scenarios. Such scenarios can be of great value to practitioners, in particular to characterize avalanche situations, to increase the transparency of the decision-making process or for the purpose of teaching and training. In the present contribution, three types of scenarios are explored in the light of the anticrack model for avalanche release: new snow situations, wind slab situations and persistent weak layer situations. In order to investigate the cause of snowpack failure in each case, characteristic snow stratifications are assumed. The scenarios are analysed case by case on a theoretical basis by studying the stability to anticrack formation and anticrack propagation. The results are judged from a practitioner's point of view by using empirical rules. The aim of the study is to show new ways of detecting the critical moments and critical configurations in avalanche situations of one of the above types. The better the cause for failure can be identified, the more specific one can be in communicating the hazard and in taking decisions to mitigate the risk.
Keywords: avalanche scenarios, anticrack model, avalanche formation
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