DEM. tide and velocity over Sulzberger ice shelf, West Antarctica

Arctic and Antarctic ice sheets preserve more than 77% of the global fresh water and Could raise global sea level by several meters if completely melted. Ocean tides near and under ice shelves shifts the grounding line position siginficantly and are one of current limitations to study glacier dynamics and mass balance. The Sulzberger ice shelf is all area of ice mass flux change in West Antarctica and has not yet been well studied. In this study, we use repeat-pass synthetic aperture radar (SAR) interferometry data from file ERS-1 and ERS-2 tandem missions for generation of a high-resolution (60-m) Digital Elevation Model (DEM) including tidal deformation detection and ice stream velocity of the Sulzberger Ice Shelf. Other satellite data such as laser altimeter measurements with fine foot-prints (70-m) from NASA's ICESat are used for validation and analyses. The resulting DEM has all accuracy of -0.57 +/- 5.88 in and is demonstrated to be useful for grounding line detection and ice mass balance Studies. The deformation observed by InSAR is found to be primarily due to ocean tides and atmospheric pressure. The 2-D ice stream Velocities computated agree qualitatively with previous methods oil part of the Ice Shelf from passive microwave remote-sensing data (i.e.. LANDSAT).