Terrestrial Radar Interferometry (TRI) August 24, 2017 We use the UW GAMMA GPRI system to study mm-scale surface displacements of mountain glaciers and other dynamic landforms. GAMMA GPRI during July 2012 survey of Emmons Glacier, Mt. Rainier GAMMA GPRI during November 2012 survey of Nisqually Glacier, Mt. Rainier Sample GPRI images (radar coordinates) and corresponding interferogram for Nisqually Glacier, Mt. Rainier. Note fringes over Lower Nisqually due to glacier surface displacement. Seasonal surface-parallel velocity and velocity change for Nisqually Glacier, Mt. Rainier. From Allstadt et al. (2015), see publications hazards Related Natural Hazards