The influence of continental shelf bathymetry on Antarctic Ice Sheet response to climate forcing

Published: Oct 1, 2016 by The PISM Authors

Depth of water on the Antarctic continental shelf is one key factor determining the maximum possible contribution of ice shelf processes (calving and sub-shelf melting/freezing) to ice-sheet mass balance. This paper uses PISM to investigate how shelf-depth changes through geologic time might have affected Antarctic Ice Sheet (AIS) dynamics. Over-deepened, shallow, and intermediate versions of BEDMAP2 bathymetry were combined with unmodified land elevations. For climate forcing similiar to the last glacial cycle, a polar AIS surrounded by shallow and intermediate bathymetries experiences rapid grounding-line advance early during the transition from interglacial to glacial conditions. The corresponding increase in mass is primarily a result of lower calving fluxes from smaller-area ice shelves. In contrast, the currently over-deepened bathymetry in the same forcing generates the expected gradual advance of grounding lines.