GNGTS 2021 - Atti del 39° Convegno Nazionale

131 GNGTS 2021 S essione 1.3 INVESTIGATING ANTARCTIC GEOTHERMAL HEAT FLUX HETEROGENEITY WITH MULTIPLE GEOPHYSICAL APPROACHES: THE WILKES SUBGLACIAL BASIN CASE STUDY F. Ferraccioli 1,2 , M. Lowe 2,3 , J. Ebbing 4 , B. Mather 5 , J. Fullea 6 , C. Green 7 1 Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy 2 NERC/British Antarctic Survey, Cambridge, United Kingdom 3 University of Edinburgh, Edinburgh, United Kingdom 4 Christian-Albrechts-University, Kiel, Germany 5 University of Sydney, Sydney Informatics Hub, Sydney, Australia 6 Universidad Complutense de Madrid, Spain 7 University of Leeds, School of Earth and Environment, Leeds, United Kingdom Introduction Geothermal Heat Flux (GHF) is a critical basal boundary condition that needs to be better constrained in order to derive more robust models of Antarctic ice sheet stability, including its responses to future ocean and climate warming. In addition to its key relevance for subglacial hydrology, glaciology and also paleoclimate research, GHF is important as both a tracer and a key influence on the tectono-thermal evolution of the Antarctic continent. Despite its importance, there are relatively few direct Antarctic GHF measurements due to the remoteness of Antarctica and its thick ice sheet cover. Geophysical estimates derived from seismology, satellite-magnetic and aeromagnetic data, and sparse MT, provide in many regions the only views on the spatial heterogeneity in Antarctic GHF. There are however significant dif- ferences in geophysical estimates of GHF derived from these different geophysical methods, and this adds uncertainty to current coupled ice sheet and Solid Earth models. Additionally, most existing geophysical studies have focussed on continental-scale GHF. These results are generally too coarse in terms of spatial resolution in particular for launching more detailed next generation studies of the influence of GHF on subglacial hydrology and ice sheet dynamics. 4D Antarctica- new effort to connect bedrock, crust, lithosphere and GHF research The international Antarctic geosciences community has recently re-iterated the key impor- tance of improving the current level of knowledge of GHF heterogeneity via more joined up and better integrated geophysical and geological investigations. As part of these ongoing international community efforts, here we present the status of a new ESA project- 4D Antarctica that over the next few years aims to help connect international An- tarctic bedrock, crust and lithosphere studies with GHF investigations, with the overarching aim of assessing its influence on subglacial hydrology. To achieve this, 4D Antarctica aims in particular to perform new analyses of recent satellite-based and airborne geophysical datasets comple- mented with independent seismological and geological constraints (where available) to derive new crust, lithosphere and thermal models for five case study areas. The five key study areas selected within 4D Antarctica include the Amundsen Sea Embayment in West Antarctica and the Wilkes Subglacial Basin, the Recovery and Pensacola-Pole Basins and the Gamburtsev Sublgacial Mountains/East Antarctic Rift System in East Antarctica. In this pre- sentation, we focus on our first results from the Wilkes Subgacial Basin study area.