2021 Avalanche Theory of Puzrin and Gaume
Geotechnical engineer Alexander Puzrin of the ETH Zürich and Johan Gaume of the Snow Avalanche Simulation Laboratory at EPFL tackled the question of why an avalanche wouldn’t have happened until well into the night when the hikers dug the tent site in the evening. They found the shallow slope was, actually, not too shallow for an avalanche. The slope is close to 30 degrees, enough for an avalanche. The appearance of the snow layers make it appear shallower than it is. Snow conditions made avalanche even more likely. There was no snow the night of the Dyatlov tragedy. As with the 2019 snow slab theory, the dense top layer of snow slides over a weaker underlayer. When the Dyatlov group dug the pit for their tent, it destabilized the crusty layer. It held for a while, then slid. The slab slid down over the weak underlayer and toward the tent.