26 August 2016
Two further videos of the Kleine Gaisl rockfall in Italy
Posted by Dave Petley
Two further videos of the Kleine Gaisl rockfall in Italy
Two further videos have now been posted to Youtube showing the Kleine Gaisl rockfall in the Dolomites of northern Italy a week ago. These seems to capture rather larger collapse events than the one that I posted a couple of days ago:
Pinopoli Clementi has posted this video, which seems to capture a big collapse involving some large boulders:
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And the same person has posted another video, taken from a different angle, that seems to show a different collapse event:
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Perhaps the most impressive thing here is way that comparatively small initial failures trigger larger events downslope, creating very large landslides. These two images, just a few seconds apart, capture this beautifully. Here is a collapse of a rock section from the upper slope:
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And a few seconds later the much larger rockfall that it initiated:
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One of the great challenges for landslide hazard assessment is being able to account for this effect, which can dramatically change the volume of the event, and thus the destructive potential and runout distance.
Thanks to Jim Falls, who highlighted these videos to me via a comment on my earlier post.
When some of the flying boulders come into view through the clouds of dust, we see flashes of white. Is this dolomite (or calcite) being pulverized from boulders striking each other (or the mountainside), being soft mineral(s)? I’m presuming the falling rocks are mostly dolomite and limestone. Does chert or other hard rock types make up much of the mass that we see falling?