Selective erosion beneath the Antarctic Peninsula Ice Sheet during LGM retreat

Published: May 1, 2015 by The PISM Authors

Erosion potential shown in color.

This paper uses PISM to investigate how the last glacial maximum Antarctic Peninsula Ice Sheet might have modified its bed both at maximum extent and during progressive grounding line retreat. The work exploits high-resolution whole-Antarctic modelling by the same author (Golledge et al 2013, Golledge et al 2014). PISM results are post-processed to compute an erosion potential which is proportional to the product of modeled basal shear stress and sliding velocity. The results show that peak subglacial erosion rates are preferentially located in areas of convergent flow and where horizontal strain rates are highest, leading to deepening of subglacial basins in such locations. Because the ice sheet selectively erodes its bed beneath outlets, over successive glacial cycles erosional deepening may accelerate the retreat of the ice sheet margin during periods of rising sea level.