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So I stumbled onto this GIF:

enter image description here

It appears that this avalanche was caused by the deep trail cut into the snow. You can see ski tracks on the slope, it looks like it's been climbed and skied a number of times, so it appears the slope was initially stable, but then this long deep trail gets cut into the side of it and all of a sudden the slab lets loose and slides. You can see in the video that the trail acts as a transform fault.

I know slopes can become more unstable later in the day after they've been in the sun for a while, so that may have also contributed to this slide, but I still think it's the deep cut trail that caused this slope to fail.

It makes me wonder if the avalanche would have triggered had they gone up a different way (switch backs, not following the same trail, etc.), or while wearing snowshoes/skins.

What's the safety way to climb up a steep slope in deep snow?

ShemSeger
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  • @WedaPashi - I'd say not duplicate, that question is about route finding and avoiding falls. This is about not triggering or being caught in an avalanche. – Pepi Nov 23 '15 at 05:45
  • @Pepi: I tend to agree. Retracted the close vote. Harmless to have it here. – WedaPashi Nov 23 '15 at 08:56
  • Related? http://outdoors.stackexchange.com/q/5030/2303 – WedaPashi Nov 23 '15 at 08:56
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    Did the guy survive – ab2 Nov 23 '15 at 10:08
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    Where's the rest of that clip? It stops just as it gets really interesting where the snow and the skier are being funneled thru a constriction. – Olin Lathrop Nov 23 '15 at 21:18
  • @OlinLathrop: Ironman comes, lifts the guy, flies and takes the guy to the top again. – WedaPashi Nov 24 '15 at 06:47
  • That's a slab release, you've got a layer of snow sitting on top of a weaker layer that gets released in a cohesive manner. The trench doesn't cause it's release, the skier does, but you can see it spans the width of the slope and goes above the trench. – furtive Nov 25 '15 at 05:12
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    @Olin Lathrop This is Julien Lopez getting caught during the 2015 Freeride World Tour in Austria. The "trail" is actually the path he rolled down after his fall. The guy had an airbag, he survived – alpadev Jan 26 '18 at 08:50
  • @OlinLathrop I had to find the clip too (yes, Julien Lopez survived): https://youtu.be/3Bx_T4PJ4Vg?t=108 – Aske B. Dec 14 '22 at 07:17

1 Answers1

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Short answer: stay near the edges of a big concave slope, near trees or rocks that could stabilized the snow pack, or at least on a convex ridge where the snow should be less deep.

Long answer: the trail that fractured is probably incidental. The sunlight was probably compacting & lubricating the snow all day, and if that guy hadn't triggered the avalanche, the next skier would have or it would have gone later by itself.

That being said, the guy in is hanging out in a bad place, as avalanches from above are more likely to funnel into his location. He's not there intentionally, he's trying to recover his ski.

I'll say that going straight up the middle of slope is bad for these reasons:

  1. a path through a concave area is more likely to be hit by avalanches triggered elsewhere
  2. skiing across the trail may have contributed to his fall
  3. walking up a nice slope like that wastes good powder, angering the snow gods
Pepi
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  • +1 for the last point. And angering the snow gods makes them punish the responsible person with various pests – one of them are avalanches ;-) . – Benedikt Bauer Nov 23 '15 at 09:47
  • I am looking closely at that "trail". I don't think it's a trail at all, but rather just the path he slid or rolled down when he fell. At the beginning of the clip, it looks like the "trail" ends just below him. – Escoce Nov 23 '15 at 15:30