I am a fan of the strange and unusual, so when our Editor-in-Chief Rory Carroll spotted this fascinating story in National Geographic about the Dyatlov Pass incident, he immediately sent it to me. He was right to do so, as this is one of my favorite mysteries and it seems it may have actually finally been solved using, of all things, digitally animated snow from a Disney movie and some old General Motors crash testing data.
If you’ve never heard of the Dyatlov Pass incident, here’s a succinct rundown from National Geographic:
In what has become known as the Dyatlov Pass incident, ten members of the Urals Polytechnic Institute in Yekaterinburg—nine students and one sports instructor who fought in World War II—headed into the frigid wilderness on a skiing and mountaineering expedition on January 23, 1959.
One student with joint pain turned back, but the rest, led by 23-year-old engineering student Igor Dyatlov, continued on. According to camera film and personal diaries later found on the scene by investigators, the team made camp on February 1, pitching a large tent on the snowy slopes of Kholat Saykhl, whose name can be interpreted as “Dead Mountain” in the language of the region’s Indigenous Mansi people.
The nine—seven men and two women—were never heard from again.
Weeks later the broken campsite, with the tent clearly cut open from the inside, and the body of one of the nine hikers was found. As the snow thawed, more and more of the carnage was revealed as bodies were found littered down the mountainside, some had their heads and chests caved in, others had their eyes or tongues missing. It was found most died of hypothermia, though some had succumbed to their injuries. Some bodies were missing clothes, while others were found with layers upon layers of clothing. Even stranger, radioactivity was detected on the bodies.
The Soviet government did what the Soviet government is best known for and quietly covered up the incident, leaving people to speculate: Could it have been some sort of nuclear accident or weapons test? Was it an attack from disgruntled locals? Or maybe a Yeti was to blame? I’ve even read a theory that infrasound could have been created when the wind hit the mountain just so, forcing the experienced mountaineers’ inner ear to vibrate in such a way as to induce extreme panic.
The most obvious answer, an avalanche, was immediately discounted by many, as the experienced mountaineers had cut in their camp on a gentle slope and there had been no snow that night. The victims’ injuries were also inconsistent with the vast majority of avalanche victims, who mainly die via affixation.
However in 2019 due to renewed interest, Russian authorities reexamined the Dyatlov Pass incident and came to the conclusion that the hikers were killed by an avalanche. That report didn’t include a whole lot of science or transparency either, so Alexander Puzrin, a geotechnical engineer at ETH Zürich, and Johan Gaume, head of the Snow Avalanche Simulation Laboratory at EPFL, took up the investigation to see if it was possible after all.
First, the pair looked at the slope of Kholat Saykhl. Snowfall and the shape of the landscape played a trick on the mountaineers, causing the slope to look less steep than it actually was. The slope was actually just steep enough to be at risk for an avalanche. When they cut into the snow to set up camp, they destabilized the snow above them. And while it wasn’t snowing that night, there were high winds that night that could have cause a build-up of snow massive enough to trigger a very small, localized avalanche.
But what about the injuries? That’s where the ’70s GM crash testing comes in:
The researchers’ computer simulations show the avalanche on Kholat Saykhl wouldn’t have been huge, perhaps involving a block of icy matter a mere 16 feet long—about the size of an SUV. The small size explains why no evidence for an avalanche was found during the initial investigation; it would have infilled the cut-out campsite before being quickly buried by fresh snowfall. But how could such a small collapse have caused such traumatic injuries?
“We discovered that, in the 70s, General Motors (GM) took 100 cadavers and broke their ribs,” says Puzrin, “hitting them with different weights at different velocities” to see what would happen during a car crash. The data was ultimately used to calibrate the safety of seat belts.
Some of the cadavers used in the GM tests were braced with rigid supports while others weren’t, a variable which ended up being serendipitous for Puzrin and Gaume. Back on the slopes of Kholat Saykhl, the team members had placed their bedding atop their skis. This meant that the avalanche, which hit them as they slept, struck an unusually rigid target—and that the GM cadaver experiments from the 1970s could be used to calibrate their impact models with remarkable precision.
The researchers’ computer models demonstrated that a 16-foot-long block of hefty snow could, in this unique situation, handily break the ribs and skulls of people sleeping on a rigid bed. These injuries would have been severe, but not fatal—at least not immediately—says Puzrin.
Jordy Hendrikx, the director of the Snow and Avalanche Lab at Montana State University, who was not involved in the current research, has long suspected an avalanche would be the most plausible villain for the Dyatlov Pass incident, but it wasn’t obvious that Kholat Saykhl was avalanche terrain. He says the team’s simulations have now recreated the deadly night with a newfound fidelity.
“[T]he way they’ve shown that empirically in their equations seems perfectly robust,” Hendrikx says. “It’s exciting how new science developments in the avalanche world can shed new light on these historic puzzles.
Indeed, dead bodies are still used in crash testing to this day, and the bodies found on Kholat Saykhl certainly sound like they were hit by something SUV-sized.
But it wasn’t just old crash testing data that helped the researchers out. Gaume was so struck by the snow animation in the Disney film Frozen he went to Hollywood and adjusted the animator’s code to allow him to simulate what lots and lots of snow does to a human body.
Putting all of these elements together led researchers to one conclusion: a freak, highly-localized avalanche of icy sheets of snow. Now, this theory doesn’t explain everything; though the radioactivity found could have been from the thorium present in camping lanterns, and the undressed bodies could have been caused by “paradoxical undressing” a phenomenon where hypothermia victims suddenly feel hot and tear off their clothes, even as they freeze to death. We’ll never know for sure, but this research does come close to closing a mystery that has endured for over 60 years.
I don’t know though, I think the smart money is still on the radioactive Yeti.