Towards better forecasts of slab avalanches

A team of researchers from EPFL and the SLF has developed a new model that describes how slab avalanches release. In the long run, it will allow improving avalanche forecasting. Slab avalanches are of particular interest since they are the most destructive, threatening both humans and infrastructure, and are very hard to forecast. Ranging in size from just a few meters to several kilometers, they are triggered when a weak snow layer buried underneath a cohesive snow slab fails. The initial crack spreads beneath the snow cover comparable to a domino effect, leading to the release of the slab avalanche. Merging the best of previous models - Within the scientific community, the release of slab avalanches has been described by two opposing models: The original model (from 1979) describes a shear fracture in the direction of the slope. The other one, called anticrack, accounts for the collapse of the weak snow layer and reproduces observed cases of remote triggering of avalanches from distant flat terrain.