Geomorphic impacts of large and rapid mass movements: a review

Studies on large and rapid mass movements have become a challenging issue in relation to paraglacial and morpho-tectonic evolution of mountain slopes. Rockfalls, rockslides and rock avalanches will be considered here on the basis of selected sites in the French and Swiss Alps and in the Himalayas. The main topics developed relate firstly to the modes of emplacement of, and the internal structures observed in, the body of the runout deposits and the influence of the surface (bedrock, superficial deposits, glacier, lake) over which the propagation takes place. The impacts of these rockslope failures on geomorphic systems (damming effects, storage, control on sediment fluxes) are then considered. Finally, the possible influence of climate change on high-alpine rockwalls, and potential threat to adjacent inhabited areas, are presented.