The velocity field and flow regime of David Glacier and Drygalski Ice Tongue, Antarctica
Abstract:We analyze spatial and temporal variability of the surface velocity field of David Glacier and its floating seaward extension Drygalski Ice Tongue. We obtain velocity measurements by combinations of automated feature tracking, interferometry and speckle tracking using 1997 Antarctic Mapping Mission-1 and 2000 Modified Antarctic Mapping Mission RADARSAT-1 data. We compare short-term velocities, three-year averaged velocities, and earlier studies to investigate whether any significant changes have occurred. Drygalski Ice Tongue advanced 2200 m over the three-year time interval, increasing its area by almost 45 km2 (an area three times that size calved off in early 2005). Our comparison suggests that the velocity field remained relatively constant from about 1991 to 2000. The yearly advance rate is similar to the long-term rate derived from a 1960 map and earlier studies, suggesting long-term steady flow. The new velocity estimates are used in combination with isostatically derived ice thickness from Ice, Cloud, and land Elevation Satellite (ICESat) data to determine basal melt.
Document Type: Research Article
Affiliations: 1: Faculte des Sciences, de la Technologie et de la Communication Universite du Luxembourg, Luxembourg, Luxembourg 2: Byrd Polar Research Center, The Ohio State University, Columbus, OH, USA 3: Jet Propulsion Laboratory, Pasadena, CA, USA 4: Neva Ridge Technologies, Boulder, CO, USA
Publication date: 2009-09-01