Dynamic crack propagation through a weak snowpack layer at the slope scale is one of these fundamental processes. Across these scales, a sequence of fracture processes results in avalanche release. Results suggest that the observed cracks propagated as mixed mode closing cracks and that the flexural wave of the slab is responsible for the energy transfer to the crack tip.ĭry-snow slab avalanche release is a complex critical phenomenon covering a wide range of scales (Schweizer and others, Reference Schweizer, Jamieson and Schneebeli2003). Finally, we used a finite element model to assess the speed of different elastic waves in a layered snowpack.
Using the discrete element method and the material point method, we reproduced the measured crack speeds reasonably well, in particular the terminal crack speed observed at smaller scales. The mean crack speeds ranged from 36 ± 6 to 49 ± 5 m s −1, and did not exhibit scale dependence. For the largest scale, up to 400 m, we estimated crack speed from an avalanche movie for scales between 5 and 25 m, we used accelerometers placed on the snow surface and for scales below 5 m, we performed a propagation saw test. As crack speed measurements can give insight into underlying processes, we analysed three crack propagation events that occurred in similar snowpacks and covered all scales relevant for avalanche release. The site provides advice and help to all those people who would benefit from making changes to their browser, operating system or computer to be able to view the web in a more accessible way.For the release of a slab avalanche, crack propagation within a weak snowpack layer below a cohesive snow slab is required. For more information on how to make your browsing easier, visit My Web My Way website, a product of a partnership between the BBC and AbilityNet. If you experience any problems or have any feedback please email us at. Making our website fully accessible is an ongoing process and we are committed to offer a user friendly experience. The FIGO website has been tested in the following browsers:
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