Earth science: Delayed slab avalanche could explain 1959 Urals mountaineering mystery

The 1959 incident at Dyatlov Pass in the Ural Mountains—during which 9 hikers died—has defied explanation for decades. An article published this week in Communications Earth & Environment suggests that a combination of several factors—including irregular topography, a cut made in the snow to install the hikers’ tent, subsequent snow deposition by strong, icy winds—triggered an avalanche that chased the experienced mountaineers from their tent and into temperatures of -25oC, resulting in their deaths.

A skiing expedition in the Ural Mountains in 1959 led to the death of an entire 9-member hiking party of Russian mountaineers, under “the influence of a compelling natural force”, as a Russian investigation concluded at the time. The hikers died from hypothermia, but the reason they left the tent inadequately clothed, and why four of them had skull or thorax injuries has remained unclear.

Alexander Puzrin and Johan Gaume present an analytical model of slab avalanche release under the environmental conditions in which the mountaineers set up their tent. The authors estimate that an avalanche may have been triggered between 9.5 and 13.5 hours after the hikers made a cut in the snow to protect their tent from the wind. This corresponds with the available evidence for the timing of the accident. The authors go on to present three-dimensional numerical simulations of the injuries likely to have been inflicted by such an avalanche, and find them to be in agreement with the autopsy reports.