Saturday 16 April 2016

Avalanche! By Paul BATAILLE

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Last winter, there were several avalanches in the Alps. Five soldiers of the “Légion étrangère” lost their lives in a big one... The danger of avalanches, however, is not in fact as great as we might imagine (the media tend to dramatize). In 2012, 17% of mountain deaths (36 people) were due to snowslide (compared to 82 who died because of hiking accidents). However, avalanches obviously still are a major danger for mountain climbers.

Avalanche meteorologists study snow and the causes of avalanches, and thus contribute to making mountaineering safer. There are three mains types of avalanches.

The first is “powder snow avalanches”. They occur during and just after snow fall. They are very fast (about 120km/h) and made of non-cohesive snow, creating a spectacular powder cloud. But those avalanches are not so dangerous because they happen during bad weather conditions, thus few people are usually out in the mountains when they happen.

The second type of snowslide, and the most dangerous, is “slab avalanches” made of compact snow. During snowfall, wind creates slabs which appear steady, but actually are not. Even a little pressure can make them come down. They can happen after just a dozen people pass over the slab, or, in a lot of cases, after another snow fall. They’re very unpredictable.

The third type of avalanche is “spring avalanches”. As the name indicates, they happen during spring when snow is melting. Because of rain, snow becomes more liquid and there is water flow.

To avoid getting trapped in an avalanche, you need to find out about the possible risks before leaving. And you must always carry an AVD (Avalanche Victim Detector), plus a  snow shovel and a probe, whatever the conditions are.

Links:

http://www.ac-grenoble.fr/eps/wp-content/uploads/2015/03/Rapport-recherche-accidentologie.pdf

Paul BATAILLE wants to become a professional mountain guide.

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