Modelling the permafrost distribution in steep rock walls in Norway

In many cold mountain areas, permafrost is a key factor for the stability of rock walls. This study provides a regional assessment of potential permafrost occurrence in steep rock walls in Norway. We present a map of steep rock walls with possible permafrost occurrence for Norway. This map is created from interpolated and gridded surface air temperature data and a terrain analysis based on a 10 m digital elevation model (DEM). The results are evaluated against field observations, a rock glacier inventory and local rock-wall temperature measurements. We show that permafrost in steep rock walls is found in around 9% of all the steep rock walls in Norway. Most frequently these are found in central southern Norway and in the Lyngen-Kafjord area in northern Norway. The study discusses the spatial distribution pattern of permafrost rock walls, and shows that in northern Norway mapped rock-slope failures are in close association with permafrost rock walls.