The occurrence of permafrost in the Italian Alps is an important predisposing factor for landslides. Debris flows are frequent on slopes overlying permafrost and are likely the result of active-layer supersaturation. The role of permafrost degradation in triggering landslides from hard rock slopes as a response to climatic warming has been pointed out only recently. Geotechnical investigations demonstrate that ice-filled fractured rock slopes at temperatures between -2 degrees and 0 degrees C are less stable than when in an unfrozen state. The Val Pola rockslide, whose accumulation mass included ice-cemented blocks, could be explained therefore as the result of strength reduction along pre-existing potential sliding surfaces, filled with warming ground-ice.
