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Titel |
The December 2008 Crammont rock avalanche, Mont Blanc massif area, Italy |
VerfasserIn |
P. Deline, W. Alberto, M. Broccolato, O. Hungr, J. Noetzli, L. Ravanel, A. Tamburini |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 11, no. 12 ; Nr. 11, no. 12 (2011-12-15), S.3307-3318 |
Datensatznummer |
250009834
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Publikation (Nr.) |
copernicus.org/nhess-11-3307-2011.pdf |
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Zusammenfassung |
We describe a 0.5 Mm3 rock avalanche that occurred in 2008 in the
western Alps and discuss possible roles of controlling factors in the
context of current climate change. The source is located between 2410 m and
2653 m a.s.l. on Mont Crammont and is controlled by a densely fractured rock
structure. The main part of the collapsed rock mass deposited at the foot of the rock wall.
A smaller part travelled much farther, reaching horizontal
and vertical travel distances of 3050 m and 1560 m, respectively. The mobility of the rock mass was enhanced
by channelization and snow. The rock-avalanche volume was calculated by
comparison of pre- and post-event DTMs, and geomechanical characterization
of the detachment zone was extracted from LiDAR point cloud processing. Back
analysis of the rock-avalanche runout suggests a two stage event.
There was no previous rock avalanche activity from the Mont Crammont ridge
during the Holocene. The 2008 rock avalanche may have resulted from
permafrost degradation in the steep rock wall, as suggested by seepage water
in the scar after the collapse in spite of negative air temperatures, and
modelling of rock temperatures that indicate warm permafrost (T > −2 °C). |
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