This is a handful of photo’s from a quick overnight trip L’Hospice du Grand-Saint-Bernard on snowshoes with three great guys from the USA. I’d picked the last couple of days to make the trip since the weather looked the best of the week. It was sunny and dry, at the top if was around -6°C in the shade but really warm in the sun.
The snow is good enough for snowshoeing but there’s not a lot of depth and the stability is best described as precarious. We found a few delicately balanced wind slabs and were able to get them to fail with the classic “whoomphing” noise as a buried weak layer collapses and expels air. We were able to do this with the additional weight of a single snowshoer.
I should quickly point out this isn’t something you should be trying! At least not unless you’re really sure what you’re doing, I was picking flat areas well away from slopes and outside the runoff from any potential slide we might trigger remotely. There’s an educational purpose to this, I can talk about the theory of these type of failures all day but if we can find a safe area with a suitable slab then it makes a powerful demonstration of an effect that, on steeper ground, is very often the precursor of a lethal avalanche. It’s also a neat demonstration of the risk level for that day. That was CONSIDERABLE which in simple terms means that an avalanche can be triggered with low additional loads like our single snowshoer.
For completeness, I’ll mention that the regional avalanche forecast mentioned the possibility of remote triggering. This basically refers to the fragile, precarious nature of the (current) snowpack where a failure, like our test slab, can propagate and cause slopes above us to fail. That’s obviously a danger to anyone travelling in the winter environment but it’s particularly worrying for snowshoers. That’s because our main tactic to avoid avalanche risk is that we stay off steep ground, our next tactic is to stay outside where the snow might run out.
I didn’t explicitly dig any pits to look at the snow pack but we’d been burying and recovering avalanche transceivers at the start of the day and found a hard slab on the surface lying on loose unstructured snow, in short an extremely dangerous situation.
