The snowpack is made up of snowfalls that accumulate on the ground and then on top of each other throughout the winter, forming a pile of several layers of snow. These layers of varying thickness will then evolve, transform under the effect of mechanical (wind, slope, crystal accumulation processes) and thermal (temperature and gradient) factors, and then melt away. The mechanical and thermal factors determine the sintering cohesion of the snowpack – and thus the risk of avalanches – which is an essential parameter for off-piste skiers.