Friday, 13 July 2012
The past 24 hours have been tense in Chamonix. Just after 5am yesterday an avalanche swept down the upper slopes of Mt Maudit, killing at least nine people and injuring numerous others.
There has been much speculation in the world press as to what caused the accident, but most is just that - we might never know exactly what happened.
The climbers had left the Refuge Cosmiques that morning after having the early breakfast and were making their way up Mt Blanc via the Trois Monts Route. This route takes you over the shoulders of Mt Blanc du Tacul and Mt Maudit before finally arriving on the summit of Mt Blanc. While the slopes of Mt Blanc du Tacul and Mt Maudit are renowned for avalanche risk, there has been hardly a drop of snow in Chamonix for the past week and there was little reason to be concerned about the risk of avalanche.
Throughout the day rescue teams from the PGHM flew back and forth to the mountain. They worked tirelessly locating victims and evacuating them. Other Guides and climbers who were on the mountain also gave assistance, including British doctors who were clients on guided expeditions. They are all to be commended for their efforts.
Having seen a photograph of the accident site there is clear evidence of multiple slides across the slope, and deep unstable layers within the snowpack. These are likely to have been caused by recent strong winds moving surface snow around the top of the mountain. For such an unstable build-up of snow to have occurred without fresh snow is highly unusual, and all those involved were very unlucky. Some have indicated that there may have been a serac collapse that triggered the avalanche - at this stage it is simply too hard to say.
Among the victims was British Mountain Guide Roger Payne. Roger was an incredibly experienced Guide who recently finished a term as the President of the British Mountain Guides Association. Roger had been guiding in the Alps for decades, and had climbed around the world including a lot of first ascents in the Indian Himalaya. Roger will be sorely missed by all who knew him and our thoughts are with his wife Julie-Ann.
There seems to be a general misunderstanding in the Press as to what causes an avalanche so I'm going to attempt to explain it simply. There are 3 key factors:
1. You need a slope steep enough, with the optimum angle being 30-45 degrees (Mt Maudit fulfills this criteria).
2. You need an unstable snowpack - This is often caused by fresh snow and wind forming a slab, or by rapid warming. There had been hardly any fresh snow this past week on Mt Maudit, and the temperature was actually slightly below the seasonal average. However there had been strong wind, and it seems that this may have transported snow from around the mountain onto the slope resulting in a dangerous area of windslab.
3. You need a trigger. This can be natural such as the weight of fresh snow, or a serac collapse. However it can also be the weight of a person acting on the slope.
Mountain accidents are common in Chamonix, with thousands of people enjoying the mountains every day. However, accidents of this scale are rare. The close-knit community of Chamonix will be hurting for some time after such a tragedy.
Photo Credit: The photo is courtesy of Klemen Gricar, a Mountain Guide working for Mountain Tracks Guiding who ate breakfast at the second sitting at the Refuge Cosmiques and was one of the first Mountain Guides on the scene after the accident. Klemen assisted the rescue teams before descending the mountain with his clients.