Controls on Spatial and Temporal Patterns of Slope Deformation in an Alpine Valley

A comprehensive surface displacement monitoring system installed in the recently deglaciated bedrock slopes of Aletsch Valley shows systematic reversible motions at annual scale. We explore potential drivers for this deformation signal and demonstrate that main driver is pore pressure changes groundwater fractured granitic mountain slopes. The spatial pattern these deformations similar magnitudes orientations adjacent points, leading to hypothesis annually caused by slope-scale elevation rock mass properties. Conversely, we show ground reaction infiltration from snowmelt summer rainstorms can be highly heterogeneous local scale, brittle-ductile fault zones are key features pressure-related deformations. also observe irreversible long-term trends (over 6.5 years data set) valley composed a larger uplift than observed our reference GNSS station Rhone valley, horizontal displacements towards valley. These observations attributed respectively elastic rebound response current glacier downwasting Great Glacier gravitational slope enabled cyclic fatigue