The researchers modeled how such winds could have accumulated snow above the tent and how much critical load would have had to be reached that would cause the top plate to slip from the weaker layer below, now that its structural integrity has was compromised to cut. “That’s how the load increased,” says Gaume. “Because there was no other way – there was no snow that night.” At one point after midnight, enough weight had been built over the thin layer that it suddenly collapsed, sending the board into the tent. It would have been a relatively small avalanche – maybe 16 feet by 16 feet – that the researchers simulated with inspiration from the Disney snow model. It would have been enough to fill the hole the campers had dug in the snow, but not enough for the rescue team to find clear signs of an avalanche 26 days later.
Here we see the disturbance caused not by an imaginary snowman, but by the combination of the cut above the tent and the snow deposited by the wind.
Video: Guame et al.An avalanche does not have to be large, however, to cause serious damage to the human body. Usually, hikers who are trapped in one are likely to suffocate. But in this case, none of the nine victims died of suffocation, and some had severe chest and head injuries.
And this can be explained by the dynamics of the plate avalanche and downwinds. Although it was not snowing at the time of the incident, the katabatic winds would have produced a much more dangerous deposit above the tent. “The wind eroded and carried the snow, which was made up of very small crystals,” says Gaume. “And when he submits, [the crystals] are very compacted. “This could have created a dense plate of snow that probably weighed 25 pounds per cubic foot. Even more unhappy for our adventurers, they had laid their skis on the floor for their tent, creating a hard substrate for the snow to crush.
Gaume and Puzrin went even further, modeling what this trauma might have looked like. To calibrate their simulation, they used data from old accident tests in the automotive industry made using human corpses, rather than mannequins. (To be fair, it was the 1970s, which was a … different time.) Then they modeled the release of simulated snow blocks of different sizes on a digital model of the human body and compared it to the results of impact tests. “What I saw was that it wouldn’t be fatal, but it would create moderate to severe injuries,” says Gaume. (Below you can see the damage that a one-meter piece of snow could do.)
As the snow from the wind would have been very dense, even a small avalanche could have caused serious injuries to the campers in the tent.
Video: Guame et al.From this, they came to the conclusion that the climbers survived the initial snowfall, cutting their way out of the tent, although some of them were seriously injured. But if he escaped a relatively small avalanche, why would he run more than half a mile away, instead of clinging to his supplies, especially his boots? Investigators found that the group had actually hidden another set of supplies in the woods, so they probably panicked at them. “You start cutting the tent inside to get out,” says Gaume. “You see, there was an avalanche, and then you might be afraid of it second avalanche. And so you may have decided that the best option would probably be to go into the woods, make a fire, and try to find the supply. ”