Geological History Constraints on the Magnitude of Grounding-Line Retreat in the Thwaites Glacier System

Principal investigator

We propose to obtain geological evidence from the Thwaites-Pine Island glacier system that will show whether glaciers were less extensive than they are at present, and, if so, when. Our goals are to: (i) determine whether previous grounding-line retreat-advance cycles, as suggested by existing geological evidence, occurred in the late Holocene; (ii) establish under what climate and sea-level boundary conditions they took place; and (iii) investigate whether this sector of the ice sheet collapsed during previous warm Pleistocene interglacial periods. Determining the conditions under which the Thwaites and Pine Island Glacier grounding lines have retreated and re-advanced in the past is critically relevant to determining whether or not present-day grounding-line retreat is irreversible.