Monitoring the Aleutian Volcanic Arc from Space

InSAR (Interferometric Synthetic Aperture Radar) is a technique for mapping subtle ground deformation using radar images from Earth-orbiting satellites. With its global coverage and all-weather imaging capability, InSAR has become an increasingly important technique for studying volcanoes in remote regions such as the Aleutian Islands. For a new book, InSAR Imaging of Aleutian Volcanoes - Monitoring a Volcanic Arc from Space, USGS scientists processed nearly 12,000 SAR images to produce about 25,000 interferograms for 52 Aleutian volcanoes that have been active during historical time. During the 20-year study period, InSAR detected some form of deformation at more than 80% of the 44 volcanoes with adequate InSAR coverage. The spatial distribution of deformation data from InSAR, combined with other monitoring data and eruption information, helps scientists to link changes on the surface to processes occurring beneath the volcano.