Aerogeophysical views of a major vulnerable marine-based sector of the East Antarctic Ice Sheet: the Wilkes Subglacial Basin

The Wilkes Subglacial Basin (WSB) continues to attract significant international attention as a potential area of substantial East Antarctic Ice Sheet (EAIS) retreat. Determining whether this sector of East Antarctica was indeed a major contributor to past global sea level rise and whether it will be again in the future beyond 2100, remains a key priority for new interdisciplinary research.Aerogeophysical exploration has unveiled that the bedrock dips inland and is grounded up to 2.1 km below sea level (bsl) within its remarkably deep sub-basins and remains at a depth 500 km inland of the present-day grounding zone.Despite a growing body of knowledge, geological, geomorphological, and oceanographic evidence for the location, amount and rate of EAIS ice sheet retreat within the WSB remains incomplete and in parts controversial, and numerical model predictions for retreat during past warmer periods (e.g. the mid-Pliocene, mid-Miocene and even more recent Quaternary times) also differ significantly.Here we review some of the results from different existing aerogeophysical campaigns and data compilations in the WSB to discuss the importance of also considering the heterogeneity in basal boundary conditions affecting and modulating EAIS behaviour, such as bed topography, geology, subglacial hydrology and geothermal heat flux, and also present several interpretations for past changes, including their associated uncertainties, unresolved issues and outstanding questions.We conclude by presenting our case for major new international aerogephysical exploration efforts such as in our newly proposed ICEOLIA ERC initiative to:1) provide key missing bathymetric and geological data coverage over the much less well surveyed continental shelf and ice shelf cavities, which is critical to study ice sheet-ocean interactions and to link marine geological/geophysical and drilling observations with the dynamics of the EAIS;2) glean an improved understanding of past processes and tipping points and finally3) help investigate 4D (i.e. both space and time dependent) Solid Earth influences on past, present and future ice sheet behaviour in this key sector of East Antarctica.