Glaciological Observations on the Ross Ice Shelf Near Scott Base, Antarctica

Abstract

Abstract On the Ross Ice Shelf near Scott Base the annual surface snow accumulation is about 18 g.cm. −2 . The increase of firn density with depth is greater than normal, due to horizontal compaction. Where the bottom of the ice shelf has a density less than 0.8 g.cm. −3 the shelf becomes brine-soaked by vertical infiltration. The bottom of the shelf is melting, at about 44 g.cm. −2 yr. −1 where the bottom is impermeable ice and 73 g.cm. −2 yr. −1 where the bottom is permeable firn. Surface velocities at 40 points within 30 km. of Scott Base vary between 4 and 840 m.yr. −1 . From the pattern of velocities, ice thicknesses and surface features, a transition zone is delineated, separating the Ross Ice Shelf from the “McMurdo Ice Shelf”.