La désagrégation des roches et les chutes de pierres en milieu de montagne polaire (Longyearbyen, Spitsberg) (Rock weathering and rock falls in polar mountain environment)

Abstract

Abstract. - The slopes around Longyearbyen are undergoing mass movements that can lead to natural disasters. A sandstone and shale rockwall is monitored in order to better understand the relationship between rock temperature, rock moisture content, weathering and rock fall occurrence in high latitude environments. Temperature and moisture conditions prone to cause frost damage are met only rarely. No evidence of a frequent occurrence of thermal shocks was found. Cryogenic weathering is thought to act on this rockwall by wedging. Rock fall activity is evaluated using sediment traps and monitoring the decay of painted squares. The largest rock fall events happened when conditions were favourable for cryogenic weathering.