Geographia Polonica (2008) vol. 81, iss. 1, pp. 19-28 | Full text
The occurrence of permafrost in the Italian Alps is an important predisposing factorfor landslides. Debris flows are frequent on slopes overlying permafrost and are likely the resultof active-layer supersaturation. The role of permafrost degradation in triggering landslides fromhard rock slopes as a response to climatic warming has been pointed out only recently. Geotechnicalinvestigations demonstrate that ice-filled fractured rock slopes at temperatures between–2° and 0° C are less stable than when in an unfrozen state. The Val Pola rockslide, whose accumulationmass included ice-cemented blocks, could be explained therefore as the result of strengthreduction along pre-existing potential sliding surfaces, filled with warming ground-ice.
Mauro Guglielmin, Department of Structural and Functional Biology, Insubria University via J H. Dunant, 3-21100 Varese, Italy