Observations of the sub-glacial hydrology of the Malaspina Glacier, using spaceborne InSAR

Two-pass Interferometric SAR (InSAR) using 1- and 3-day pairs of ERS-1 and -2 SAR data has been applied to the observation of ice subsidence and rebound, interpreted as resulting from the influx and drainage of water through sub-glacial and/or englacial cavities. The Malaspina (Alaska), the largest piedmont glacier in the world, is characterised by slow or stagnant horizontal ice flow, allowing phase changes due to vertical ice movement to dominate. InSAR analysis has been augmented using Digital Surface Models (DSM) from the Shuttle Radar Topography Mission (SRTM) and interpretations of sub-glacial drainage patterns are presented.