Articles | Volume 14
https://doi.org/10.5194/adgeo-14-211-2008
https://doi.org/10.5194/adgeo-14-211-2008
10 Apr 2008
10 Apr 2008

Catastrophic glacial multi-phase mass movements: a special type of glacial hazard

D. A. Petrakov, S. S. Chernomorets, S. G. Evans, and O. V. Tutubalina

Abstract. Many glacier-related hazards are well typified and studied, but some events stand out from conventional classifications. The Kolka-Karmadon catastrophic event on 20 September 2002 in North Ossetia, North Caucasus, Russia is used as an example of a complex glacier failure exhibiting characteristics such as high mobility, long runout, ultrarapid movement and multiphase behaviour. We consider terminology protocol for glacier hazard classification and then, using the Kolka-Karmadon event and several other examples from around the world, we propose a new term for this family of events. Catastrophic glacier multi-phase mass movement (CGMM) is described and further illustrated by eight major events from Russia, Georgia, Peru, Chile, and Canada. CGMM have a combination of specific features: extraordinary velocities and long-distance runout despite low path angle; progressive fluidisation along travel path; superelevation and run-up of the moving mass, air blast wave in the avalanche flow phase; entrainment of available materials in its path, and the repeated nature of the event. CGMM events may affect areas remote from glaciers which were previously considered as safe.

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