The combined effect of microstructure and fabric on the densification of polar and alpine snow

This collaborative work focuses on fundamental questionings surrounding the physics and mechanical properties of snow and firn. In particular, it aims at exploring the central role of the microstructure and the fabric of the snow-pack and its evolution with depth and time both in perennial polar and in seasonal alpine conditions. The microstructure of porous ice is defined here as the geometry of the ice-air interface, the fabric is defined as the crystal orientation of the snow crystals. While most past efforts focused on the geometrical properties of snow, this collaborative work stands on the innovative objective to take into account both geometric and crystallographic aspects of microstructure as key elements to improve densification laws of snow and firn. Practically, this was done by associating 3D tomography imaging available at SLF with crystallographic orientation measurements performed by M. Montagnat. Natural snowpack from the EastGRIP Greenland site was studied together with samples mechanically tested in the laboratory.

This fellowship-program was involved in the CNRS PICS research exchange program between WSL-SLF and  IGE and Centre d’Etude de la Neige (CEN - MéteoFrance) in Grenoble. Cooperation therefore included Pascal Hagenmuller and Marie Dumont from CEN.