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| Titel |
Influence of weak layer heterogeneity and slab properties on slab tensile failure propensity and avalanche release area |
| VerfasserIn |
J. Gaume, G. Chambon, N. Eckert, M. Naaim, J. Schweizer |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 2 ; Nr. 9, no. 2 (2015-04-27), S.795-804 |
| Datensatznummer |
250116785
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| Publikation (Nr.) |
 copernicus.org/tc-9-795-2015.pdf |
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| Zusammenfassung |
| Dry-snow slab avalanches are generally caused by a sequence of fracture
processes, including failure initiation in a weak snow layer underlying a
cohesive slab followed by crack propagation within the weak layer (WL) and
tensile fracture through the slab. During past decades, theoretical and
experimental work has gradually increased our knowledge of the fracture
process in snow. However, our limited understanding of crack propagation and
fracture arrest propensity prevents the evaluation of avalanche release sizes
and thus impedes hazard assessment. To address this issue, slab tensile
failure propensity is examined using a mechanically based statistical model
of the slab–WL system based on the finite element method. This model
accounts for WL heterogeneity, stress redistribution by slab elasticity
and possible tensile failure of the slab. Two types of avalanche release
are distinguished in the simulations: (1) full-slope release if the
heterogeneity is not sufficient to stop crack propagation and trigger a
tensile failure within the slab; (2) partial-slope release if fracture arrest
and slab tensile failure occur due to the WL heterogeneity. The probability
of these two release types is presented as a function of the characteristics
of WL heterogeneity and the slab. One of the main outcomes is that, for
realistic values of the parameters, the tensile failure propensity is mainly
influenced by slab properties. Hard and thick snow slabs are more prone to
wide-scale crack propagation and thus lead to larger avalanches (full-slope
release). In this case, the avalanche size is mainly influenced by
topographical and morphological features such as rocks, trees, slope
curvature and the spatial variability of the snow depth as often
claimed in the literature. |
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