Borehole drilling to the bed of ice stream B, Antarctica

The great ice streams flowing through and out of the west antarctic ice sheet move at speeds of hundreds of meters per year, while the ice sheet itself moves only a few tens of meters per year (Whillans, Bolzan, and Shabtaie 1987). What gives rise to the dramatic increase in the speed of the ice streams over the neighboring ice sheet? Our goal is to understand the basic physical mechanism that controls the rapid motion, both because it is an interesting glaciological phenomenon in its own right and because it may have important consequences for worldwide climatic change. A realistic understanding of the interaction of climatic and sea-level change with the west antarctic ice sheet will have to take into account the dynamics of this large ice mass, particularly the rapid motion of its ice streams.