Avalanche simulations based in part on General Motors crash tests and animations used in the movie Frozen could explain the mysterious “Dyatlov Pass” case.
Drama in the Urals
The January 23, 1959, ten members of the Polytechnic Institute of the Urals of Yekaterinburg put on their skis, direction “the unknown”, in the north of the Urals. During the expedition, one of them suffered from joint pain and turned back. Led by 23-year-old engineering student Igor Dyatlov, the rest of the group continues on its way.
On February 1, the team set up camp on the snowy slopes of the Kholat Saykhl. The photographic film and the diaries discovered on site bear witness to this. Then nothing more. No more news for several weeks.
A rescue mission is then organized. On site, investigators only found a tent almost buried under the snow and cut from the inside. The bodies of the members of the expedition will be revealed during the following weeks within a radius of 1.5 km, thanks to the snowmelt. Some are naked, others have broken heads and chests. It also lacks the eyes of one of the victims, the tongue and eyes of another.
The criminal investigation carried out at the time concludes in a death caused by an “unknown natural force” before being ignored. Of course, it does not take less to arouse the interest of the general public. What happened ? Who is responsible ?
Military, Yetis, Aliens or Avalanche
Very quickly, some blame the state. Perhaps, they argue, the Soviet authorities killed the hikers because they stumbled upon a top secret experience. Or maybe they were hit by debris from a weapons test? Meanwhile, others are betting on a yeti or alien attack.
The case thus remained as it was for sixty years, inspiring books, films and other television shows, before the media took an interest in it again in 2019. In the process, the Russian authorities reopened the case and pointed out the avalanche thesis. Problem: the report does not provide any clear explanation of the circumstances of this snowfall. Besides, the slope was not very steep and it hadn’t even snowed that night. Also, doubts persisted.
More recently, two scientists, Alexander Puzrin, geotechnical specialist at Zurich Polytechnic, and Johan Gaume, director of the Avalanche Simulation Laboratory at Lausanne Polytechnic, looked into the matter. Their findings, published in the journal Earth and environment communications, put forward the same hypothesis of the avalanche, but support it with models and data.
A block of snow five meters in diameter
For several months, the two men teamed up to create analytical models and computer simulations. Quickly, they noticed the argument that the slope of the slope was too low did not hold water. In reality, it was close to the 30 °, the minimum required for many avalanches.
Reports from the original investigation also described an underlying layer of snow that had not clumped together, forming a fragile base on which a large amount of snow could easily slide. To set up their tent, the members of the expedition would then have cleared this layer of snow.
However, for an avalanche to occur, snow must still accumulate. The weather reports did not predict the evening of the incident. In contrast, there were strong gusts of wind capable of carrying large amounts of snow from the heights.
According to computer simulations, the ensuing avalanche would have been small, involving a block of frozen material barely five meters. The snow entrained by the avalanche would thus have filled the space cleared for the establishment of the tent before being quickly buried under a layer of fresh snow.
However, a question remains: How could a phenomenon of this size have caused such serious injuries?
To try to answer it, the researchers relied on unusual sources. Johan Gaume recalled being impressed by the way the movement of snow was portrayed in the animated film Frozen. He therefore turned to the specialist who worked on the special effects of the Disney film. The researcher then drew inspiration from these tips to modify the snow animation code in its models aiming to simulate the impact of these snowflows on the human body.
To continue, the duo needed to realistically estimate the forces and pressures exerted by such an avalanche on the human body. This time, they turn to the American automaker General Motors (GM) which, long before the arrival of the models, had subjected several corpses to different pressures exerted at different speeds in the 1970s.
Some of the corpses used for these tests had been reinforced with rigid supports, which suited the researchers. Indeed, the members of the expedition had installed their beds on their skis. Thus, the avalanche should have struck an exceptionally rigid target when it was time to strike. The experiences of General Motors could therefore be used to calibrate impact models accurately.
With this information in hand, the researchers finally demonstrated that a block of heavy snow measuring almost five meters in length would have may have inflicted the injuries observed on the corpses found.
“Certain gray areas will always remain”
After the avalanche fell, scientists speculate that the team members got out of the tent by cutting it up before taking shelter more than a mile away, after descending the slope. Those who were injured were not found around the tent. So it is possible that they moved on their own or, more likely, that they were moved by their friends in an attempt to save them.
Note that the two researchers do not claim to have solved the mystery definitively. They advance here a plausible explanation based on concrete models. “Obviously, some gray areas will always remain“, Recognizes Johan Gaume.
However, certain elements surrounding their death continue to raise questions, such as the fact that several individuals were undressed (the paradoxical undressing could be an explanation). Several bodies were also radioactive. Here, the presence of thorium in camping lanterns could be a lead. As for the missing eyes and tongue, the scavenger trail is preferred.