Emerging applications of interferometric synthetic aperture radar (InSAR) in geomorphology and hydrology

Interferometric synthetic aperture radar (InSAR) is a powerful geodetic tool used to construct digital elevation models of the earth's topography and to image centimeter-scale displacements associated with crustal deformation and the flow of ice sheets- The past decade has seen significant improvements in our understanding of earthquakes, volcanoes, and glaciers as a direct result of this technology. Geomorphology and hydrology can also benefit from InSAR. A small but growing body of work shows that it is possible to interferometrically measure centimeter-scale motions associated with unstable slopes, land subsidence, fluctuating soil moisture and water levels, and deforming river-ice cover. Maps of interferometric correlation provide information about the structure of snow and reveal areas disturbed by erosion, sedimentation, flooding, snowfall, and aufeis growth. At present, such techniques are underdeveloped and largely overlooked by the geographic and radar communities. This article reviews these emerging geomorphic and hydrologic applications of InSAR and presents a first demonstration of motion detection for river ice.