Localized basal freezing within George VI Ice Shelf, Antarctica

Abstract

Hobbs Pool is an area of thin ice shelf situated within George VI Ice Shelf, Antarctica. Thicker ice shelf surrounding Hobbs Pool isolates the upper 155m of the water column from water lying at the same depth elsewhere under the ice shelf. Summer melt-water lakes drain through crevasses at Hobbs Pool forming a 155m thick layer of low-salinity water close to its freezing point. Colder and more saline water in the lower part of this layer leads to in-situ freezing of fresher water lying above it. Below 155m depth, the water temperature and salinity are linearly realted by basal melting which is observed elsewhere under the ice shelf. The surface ice shows areas of deformation and deposits of subglacial rock debris which may result from upward particle paths in the area. -from Authors