Investigations of the configuration, physical properties, and dynamics of the portion of the West Antarctic inland ice sheet that flows in to the floating Ross Ice Shelf will be continued. Two seasons of field work (1987-88 and 1988-89) will be followed by one year of data analysis (1989-90). The emphasis of this work will be to study further the characteristics and distribution of the active subglacial till layer found under one section of ice stream B, to compare and contrast ice streams B and C and the intervening ridge with respect to their basal characteristics, internal physical constitutions, and surface configurations, and to conduct a reconnaissance survey of ice streams D and E. Measurement methods will include airborne radar, seismic shooting, and recording of microearthquakes. Supplementary investigations will include ground-based radar studies of crevasse depths, basal reflection strengths and depolarization phenomena, and electrical resistivity profiles. Gravity measurements, determinations of ice-movement rates, and core sampling for calculation of surface net balance rates will be carried out in cooperation with other ongoing research.
