The researchers modeled how these winds could have accumulated snow above the tent and how long it would have taken to reach a critical load that would cause the top slab to slide from the weaker layer below, now that the cut down. “That’s how the load increased,” Gaume says. “Because there was no other way, there was no snow that night.” Some time after midnight, enough weight had accumulated over the weak layer that suddenly collapsed and sent the slab into the tent. It would have been a relatively small avalanche (perhaps 16 feet by 16 feet) that the researchers simulated inspired by Disney’s 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 on 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 get stuck in one are likely to drown in just one. But in this case, none of the nine victims drowned and some suffered severe chest and head trauma.
This is also explained by the dynamics of the avalanche of slabs and downwinds. Although it was not snowing at the time of the incident, the katabatic winds would have produced a much more dangerous type of deposit over the tent. “The wind eroded and carried the snow, which was made up of very small crystals,” Gaume says. “And then, when it is deposited, [the crystals] they are very compacted. “This could have created a dense slab of snow that weighed perhaps 25 kilos per cubic foot. And even more unfortunate for our adventurers, they had laid the skis as ground for their tent, creating a substrate. hard for the snow to crush them.
Gaume and Puzrin went even further by shaping the appearance of this trauma. To calibrate their simulation, they used data from old automotive crash tests done on human corpses, rather than mannequins. (To be fair, it was the 1970s, which was a … different time.) They then modeled the release of simulated snow blocks of different sizes into a digital model of a human body, and compared it to the results of the shock tests. “What we saw is that it would not be fatal, but would create moderate to severe injuries,” Gaume says. (Below you can see the damage a piece of snow a meter in diameter could do).
As the snow deposited by the wind would have been very dense, even a small avalanche could have caused serious injuries to the tent campers.
Video: Guame et al.From this, they concluded that the mountaineers survived the initial crushing of the snow and left the tent, although some were seriously injured. But if they had escaped a relatively small avalanche, why would they flee more than half a mile away, instead of staying to dig up supplies, especially boots? Investigators found that the group had hidden another supply in the forest, so they may have gone towards them in panic. “You start cutting the tent inside to get out,” Gaume says. “You see there was an avalanche, and then you might be afraid of one second allau. So they may have decided that the best option would probably be to go into the woods, make a fire and try to find the supply. “