The pulsing nature of powder snow avalanches

There is growing evidence that the destructive capacity of powder snow avalanche (PSA) is caused by high-energy pulses within his complex layering. Field observations at the VdlS have shown two processes closely related to pulse formation: (i) the propagation of waves on top of the dense basal layer, and (ii) the development of large coherent structures within the transition layer. Both processes are associated with maxima in the dynamic pressure measured on a fixed obstacle. By combining new experimental techniques, such as GEODAR or high-speed cameras, with state-of-the-art modeling of the complex rheology of snow, we now have the tools to study PSAs with unprecedented detail. The goal of this project is to understand the origin and nature of the high-energy pulses present in both the dense basal granular layer and the transition layer of PSA, and to develop a model to study the interaction between avalanche pressure pulses and structures.