Ice Flow in the North East Greenland Ice Stream

• Main Authors: Ian Joughin, Mark Fahnestock, Jonathan L. Bamber, Doug Macayeal
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: June 4; 1999 3; 34; Greenland; East Greenland; Ice Sheet
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.570.928; http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/17537/1/99-0996.pdf

We have measured ice flow and detailed topography in northeastern Greenland using satellite-based Synthetic Aperture Radar ( S A R) interferometry. The object of this study is the large ice stream that drains this quadrant of the ice sheet. A single S A R interferogram allows the measure-ment of one component of motion over a several-day long interval. We have used a set of such measurements, from several look directions, to produce a mosaic of ice flow velocity. The result-ing flow field is tied to an estimated balance velocity distribution in slow moving areas, and assumes flow to be locally surface parallel. In spite of these assumptions, the velocity field is the most detailed, consistent data set available over a flow feature of this size. It compares with GPS control points at the 5 m/yr level. In the process of mapping ice flow velocity, an enhanced eleva-tion model of the ice stream was produced. The elevation model is based on a blend of interfero-metrically-derived short wavelength topography and radar-altimetry based longer wavelength topography. This enhanced model has improved information on local surface slope, which was useful for estimating the horizontal components of the velocity field.