Footage uploaded on Instagram by Harry Shimmin, one of the people on the trekking tour, showed snow starting to break down a mountain in the distance, before sweeping towards them and forcing the group to take cover as the snow went over the top of them.
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“I left it to the last second to move, and yes I know it would have been safer moving to the shelter right away. I’m very aware that I took a big risk. I felt in control, but regardless, when the snow started coming over and it got dark/harder to breathe, I was bricking it and I thought I might die.”
Flow velocities of snow avalanches vary between 50 and 200 km/h for large dry snow avalanches, whereas wet avalanches are considerably denser and slower (20–100 km/h, McClung and Schaerer, 2006). If the avalanche path is steep, dry snow avalanches may generate a powder cloud.
The guy with the camera would then have been somewhere between 1.9-2.4km away from the top of the glacier, given the entire fall took approx. 48 seconds to reach his location.
By the time it reached the valley, it’s quite likely the snow was mixed with quite a few rocks as well. Super dangerous.
Here is the original reddit post by the guy who shot the video