Continent-Wide, Interferometric SAR Phase, Mapping of Antarctic Ice Velocity

Abstract

Surface ice velocity is a fundamental characteristic of glaciers and ice sheets that quantifies the transport of ice. Changes in ice dynamics have a major impact on ice sheet mass balance and its contribution to sea level rise. Prior comprehensive mappings employed speckle and feature tracking techniques, optimized for fast-flow areas, with precision of 2-5 m/year, hence limiting our ability to describe ice flow in the slow interior. We present a vector map of ice velocity using the interferometric phase from multiple satellite synthetic aperture radars resulting in 10 times higher precision in speed (20 cm/year) and direction (5°) over 80% of Antarctica. Precision mapping over areas of slow motion ('1 m/year) improves from 20 to 93%, which helps better constrain drainage boundaries, improve mass balance assessment, evaluate regional atmospheric climate models, reconstruct ice thickness, and inform ice sheet numerical models.