Gravitational mass movements frequently occur in combination with other natural hazards, such as earthquakes and floods leading to severe losses of life and infrastructure worldwide. Objective and dynamic landslide hazard assessment requires profound knowledge about spatiotemporal occurrence of landslides. We use time series of optical satellite remote sensing data for automated detection of slope failures in order to reconstruct backdated landslide activity and to monitor ongoing process activity. High-resolution SAR data are used in combination with optical images for the detection of slope deformations which are related to the activation of mass movements.