Recent snowfalls of 10-20 cm above 2500 m have made for some great ski conditions in the last few days in the Northern French Alps. While current avalanche activity has been limited to a few areas mainly above 2500 m, e.g. Mont Blanc (the Vallée Blanche and above Courmayeur), the biggest dangers for off-piste skiers at the moment have to do with off-piste skiing and touring on glaciers.
The snow bridges, that have formed over glacial crevasses as a result of these recent snowfalls, are mostly very thin at this time of year. As defined by Wikipedia a snow bridge is “an arc across a crevasse, a crack in rock, a creek, or some other opening in terrain. It is typically formed at first by snow drifting, which first creates a sort of cornice, and then may gradually grow to reach the other side of the opening forming a ‘bridge'”.
The main thing to remember is that, unless you are very experienced at glacier travel, most snow bridges look the same from above. So you can’t tell whether the thickness of a snow bridge over a crevasse is 10 cm or 3-4 m thick. One snow bridge may hold your weight – the other one won’t. Guessing which one is like playing Russian roulette. Furthermore, skiing off-piste on glaciers is very tricky, and potentially very dangerous at this time of year because the process of snow bridge forming/filling in of the crevasses has only just started. So it’s a mine field of potentially deadly falls.
Luckily for the snowboarder who fell 10 metres into a crevasse into Tignes’ ‘Grande Motte’ glacier on Saturday, he lived. Many people have died from such a fall. Here’s a link to the story by the Dauphiné Libéré.
If you want to venture into the powder in glaciated terrain, the best thing would be to hire one of the very experienced UIAGM / IFMGA mountain guides. They’re based throughout the Alps and have extensive training in glacier travel and crevasse rescue. Where this particular crevasse fall took place, you can find them at for example, the Bureau des guides de Tignes , Val d’Isère… etc. You can learn a lot from them on this fascinating subject and have fun at the same time.
At Henry’s Avalanche Talk we’re passionate about all things Off-Piste: avalanche-related and otherwise. For further info and articles on Off-Piste, having fun and staying safe here’s a link to our Henry’s Avalanche Tour of Events (mostly virtual) kicking off soon! https://henrysavalanchetalk.com/uk-events/the-off-piste-awareness-tour-2020/
Learn how to be safe AND have a lot more fun Off-Piste because “Safety is Freedom”!
There’s a long list of evidence that shows how applying simple frameworks, checklists and memory aids reduce risk in ‘high consequence, low feedback’ risk contexts prevalent in: aviation, military, finance, health care, avalanche terrain etc.
See our HAT quick reference ‘Safety is Freedom Framework’ for accident reduction in avalanche terrain. The Framework is aimed at all levels of off-piste and touring: for beginners: a point of departure; for experts: a guide for further learning; for pros: it’s a great framework for client training and quick memory aid.
The Framework is best if accompanied by training such as HAT events and on-snow courses, but it’s also a useful companion for all training as it focuses on the basic key points that all avalanche training courses address – it helps you to keep focused on the essential accident reduction points.