East Antarctic ice sheet and ocean interactions during past warmer than present climates

Antarctica´s contribution to sea-level rise is the single greatest uncertainty in global climate predictions for the coming decades and centuries. One of the critical knowledge gaps to understand and quantify mass loss from Antarctica in a warmer world is the heat exchange across Antarctica’s continental shelves, governed by the interplay of Southern Ocean water masses and the ice sheet. The ICEAN project will fill this void by providing high resolution, multi-disciplinary proxy data on water masses, ocean temperatures and ice sheet position for a carefully chosen shelf to open ocean transect of geological archives across the Prydz Bay margin (East Antarctica), which record past warm conditions during the Middle Pliocene Warm Period (MPWP) interglacials between 3.1 and 3-0 Ma, relevant to near future temperature ranges (2-3oC higher global temperatures) under the Intergovernmental Panel on Climate Change (IPCC) intermediate greenhouse gas emission (GHG) scenarios. This project aims to test three hypotheses for the MPWP interglacials between 3.1 and 3.0 Ma: Hypothesis 1: East Antarctic ice sheet (EAIS) retreated across Prydz Bay continental shelf. Hypothesis 2: Reduction of formation and export of Antarctic Bottom Water (AABW) from Prydz Bay drove enhanced Circumpolar Deep Water (CDW) intrusions onto the continental shelf. Hypothesis 3: Poleward position of the Ant-arctic Circumpolar Current (ACC) driven by poleward westerly wind migrations facilitated enhanced intrusion of CDW onto the continental shelf.