Dyatlov Case is a big thing in Russia,
because it has not been resolved, and there are a lot of conspiracy theories
surrounding it, which people naturally like.
On January 1959, a group of 10 experienced mountaineers from the Ural Polytechnic Institute
set off on an expedition to the Otorten Mountain, in the former Soviet Union.
At the outset, one member of the team decided to turn back because of severe joint pain.
He never saw his friends again.
On February 26, just one month after the expedition began,
a rescue team found the group's tent cut open from the inside.
All nine mountaineers were found dead within 1300 meters from the tent,
in a macabre scene that led to a controversial three-month investigation.
The authorities finally concluded that a compelling natural force
had caused the death of the mountaineers.
60 years later, the incident is now part of Russian lore
and continues to capture imagination, as countless theories are spawned due to lack of evidence.
Johan Gaume and Alexander Puzrin,
professors from EPFL and ETH Zürich in Switzerland, are changing this.
And recently provided scientific evidence
suggesting that a delayed snow slab avalanche may have urged the nine hikers
to exit the tent in the middle of an extremely cold night, which ultimately led to their death.
A small slab avalanche released right above the tent and surprised them while they were sleeping.
Some of them got injured, and they had to cut the tent from the inside to escape
and without appropriate clothes, it was impossible for them
to survive with these extreme weather conditions
especially because they didn't want to leave their injured friends behind.
Even today, it's widely believed that avalanches only happen on slopes above 30 degrees.
Yet the campsite was on a slope that was less than 30 degrees.
How could an avalanche happen?
Could one be responsible for the crushed ribs and broken skulls succumbed by some of the victims?
The local topography played a special role in the Dyatlov Case.
There was a larger shoulder followed by the slope, with smaller steps.
Because of the smaller steps, the local inclination of the weak layer was steeper.
And because of the shoulder, the strong catabatic winds which were blowing that night
deposited the snow just above the tent, loading the slab and causing the avalanche.
We're doing here a proof of concept for the Dyatlov Case.
This is a snow fracture experiment.
We have a nice and strong slab, and at the bottom, we have a very weak base made of depth hoar.
And what i will do is initiate a crack in the weak layer
until the crack propagates, and the slab slides down the slope.
This avalanche releases very big blocks.
And you can imagine that if you receive such big blocks on your ribs,
it can really lead to serious injuries.
The slab avalanche did not happen immediately after the cut.
There was a significant delay.
The Dyatlov group cut the slope and installed the tent.
And meanwhile outside, strong catabatic winds were transporting snow
which accumulated, due to the special topography, just above the tent
loading the slab until eventually the weak layer below the slab loses its strength,
and the slab released.
The models that we developed in this paper can be used in the future
for forensic investigations related to avalanche impact on structures or on human bodies.
I believe that our research contributed to
demonstrate the plausibility of the avalanche hypothesis,
and based on solid physical models.
And on top of that, on a personal level, this is very likely the most exciting research
that I've been doing in the past years,
and it allowed me to start a beautiful collaboration
and to start a very nice friendship with Alexander Puzrin.
The mountain pass nearby the incident has since been called the Dyatlov pass,
named after Igor Diatlov, the 23 year old student who led the ill-fated expedition.