29 August 2015

A large rockfall on the Tour Ronde, Mont Blanc

Posted by Dave Petley

Tour Ronde, Mont Blanc

The Tour Ronde is a massif the Mont Blanc region of the Alps, on the border between France and Italy.  On Thursday the southeast face of this mountain suffered a significant landslide.  Planet Mountain has a nice piece providing an account of the landslide:

Gianluca Marra, a Mountain Guide from Courmayeur … told planetmountain.com that “a first rockfall took place at around 8:30, a second one just over an hour later” adding that “the rockfall occurred on a section of the SE Face, on the spur a bit to the right of the Normal Route up Tour Ronde.”

Luckily, no-one was killed or injured in the Tour Ronde rockfall, but it was captured on video by Gianluca Marra, and it is now on Youtube.  Two rockfalls occurred, about an hour apart.  This is the second event:

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The capture of both the rockfall component of this landslide (including the detachment of a series of large boulders) and the runout component (and in particular the slow bulldozing effect at the end of the movement phase, as was also observed in the Mount Dixon landslide in New Zealand) is particularly helpful.  Once again the way in which the rockfall component resembles a fluid flow is notable.  This is particularly evident in this remarkable photograph of the first collapse, also from Planet Mountain:

Tour Ronde

Gianluca Marra via Planet Mountain

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Finally, Planet Mountain also has a high resolution photograph of the aftermath of the Tour Ronde rockfalls after the second collapse, also taken by Gianluca Marra:

Tour Ronde

Gianluca Marra via Planet Mountain

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