Cook-glacier-Ocean system, sea Level and Antarctic Past Stability

The objective of COLLAPS is to investigate current and past oceanic conditions and ice-sheet dynamics in the Cook-Ninnis sector (Wilkes Land Subglacial Basin, WSB), which remains poorly constrained and largely unexplored. The Cook glacier drains most of the WSB, about 3-4 m sea level equivalent. Although observations show that most of West Antarctica ice shelves are thinning due to ocean warming, we know little about the vulnerability of East Antarctica. Totten glacier is one of the most vulnerable sector so far, but some paleo-records suggest that the grounding line retreated significantly during the Mid-Pliocene Warm Period (3.3 Ma) in particular in the WSB. Large knowledge gaps about the bathymetry and subglacial topography in the Cook-Ninnis sector, and about oceanic conditions hamper a broader understanding of Antarctic vulnerability past, on-going and project climatic changes. To fill part of those gaps, COLLAPS proposes to collect geophysical-geological but also oceanographic data, with mutidisciplinary and novel approach, to retrieve the high-resolution morphology of a shelf valley-cut across the continental shelf edge, in front of the Cook glacier. A second objectives is to collect a new set of oceanographic measurements across the continental margin and to localise possible intrusions of warm waters and downslope flow of dense shelf waters. As a third objective, COLLAPS will reconstruct LGM and Cenozoic paleodepth morphology and depositional processes of continental margin by means of a marine seismic survey. Correlation with IODP exp. 318 stratigraphy will support the reconstructions. COLLAPS involves a highly qualified team, with complementary skills to st udy both the local geological and oceanographic conditions and their connections to global climate dynamics. Early career scientists will be involved in a multidisciplinary and international team. COLLAPS is part of a larger multidisciplinary scientific consortium to design a new ERC-SYNERGY proposal.