The Motion Field of Northern Larsen Ice Shelf Derived from Satellite Imagery
The motion field of the northern Larsen Ice Shelf, Antarctic Peninsula, was analyzed, based on Landsat data from 1986 to 1989, ERS-SAR data from1992 to 1997, and comparative field measurements along three transects. During this period the northern sections of the ice shelf showed steadyretreat, which culminated in the disintegration of the two ice shelf sections north of the Seal Nunataks in January 1995. Velocities of these two sectionswere derived by cross-correlation, using SAR images of one-year time intervals and Landsat images of one- to three-year intervals. A slight increaseof velocity was observed, as crevasses and rifts opened before the final disintegration. In addition, an interferometric motion analysis was carried outfor the ice shelf around and south of Seal Nunataks based on an image pair from the ERS-1/ERS-2 Tandem Mission in 1995. This analysis reveals acomplex pattern of tidal flexure in the grounding zones, as well as rifting and shear zones on the ice shelf. In addition, the motion of the main inputglaciers was derived.