Norway's Operational Avalanche Activity Monitoring System Using Sentinel-1

Knowledge of the spatial and temporal occurrence of avalanche activity is critical for avalanche forecasting and hazard mapping. We present an automatic avalanche monitoring system for Norway. Our system enables us to monitor the release of large avalanches daily. The system monitors the forecasting regions of the Norwegian Avalanche Warning Service continuously throughout the winter. We apply our detection algorithm to an RGB composite of two successive Sentienl-1 images from the same orbit. Detections from several orbits are combined to improve the estimate of the avalanche release time. Our probability of detection depends on the avalanche type and size and is 57% combined.