Theory has suggested that the West Antarctic Ice Sheet may be inherently unstable. Recent observations lend weight to this hypothesis. We reassess the potential contribution to eustatic and regional sea level from a rapid collapse of the ice sheet and find that previous assessments have substantially overestimated its likely primary contribution. We obtain a value for the global, eustatic sea-level rise contribution of about 3.3 meters, with important regional variations. The maximum increase is concentrated along the Pacific and Atlantic seaboard of the United States, where the value is about 25% greater than the global mean, even for the case of a partial collapse.
In the figure, Antarctic surface topography (gray shading) and bed topography (brown) define the region of interest. For clarity, the ice shelves in West Antarctica are not shown. Areas more than 200 meters below sea level in East Antarctica are indicated by blue shading. Notations are: AP, Antarctic Peninsula; EMIC, Ellsworth Mountain Ice Cap; ECR, Executive Committee Range; MBLIC, Marie Byrd Land Ice Cap; WM, Whitmoor Mountains; TR, Thiel Range; Ba, Bailey Glacier; SL, Slessor Ice Stream; Fo, Foundation Ice Stream; Re, Recovery Glacier; To, Totten Glacier; Au, Aurora Basin; Me, Mertz Glacier; Ni, Ninnis Glacier; WSB, Wilkes Subglacial Basin; FR, Flood Range; a.s.l., above sea level.
Citation: Bamber, J., Riva, R., Vermeersen, B., and LeBrocq, A., Reassessment of the Potential Sea-Level Rise from a Collapse of the West Antarctic Ice Sheet, Science 324 (5929), 901. [DOI: 10.1126/science.1169335]