Antarctic geothermal heat flux: past, present and future perspectives

• Main Authors: Ferraccioli, F, Pappa, F, Dziadek, R, Gohl, K, Wiens, D, Shen, W, Macelloni, G, Fullea, J, Burton-Johnson, A, Halpin, J, Bredow, E, Verdoya, M, Armadillo, E, Matsuoka, K, Mather, B, Hasterok, D, Greene, C
• Format: Conference Object
• Language: English
• Published: . 2019
• Subjects: Earth Sciences; Geology; Tectonics; Antarctic; Byrd; Marie Byrd Land; Antarc*; ice core; Ice Sheet
• Online Access: https://www.isaes2019.org:12090/home/; http://ecite.utas.edu.au/136136

Geothermal Heat Flux (GHF) measurements and estimates of GHF via geophysical and thermalmodelling are required to better predict past, present and future Antarctic ice sheet behaviour,including its dynamic responses to ocean and climate warming. In addition to its relevance formodelling subglacial hydrology and ice sheet dynamics, including e.g. the onset and maintenance ofenhanced glacial flow, GHF serves as a boundary condition for paleotopography and paleoclimatestudies (in particular for deep ice core drilling site selection), and is also important as both anindicator and an influence on the tectono-thermal evolution of the lithosphere. Despite its pivotal importance, there is still a paucity of direct Antarctic GHF measurements.Consequently, geophysical estimates derived from seismology, satellite-magnetic and aeromagneticdata, and sparse MT, provide in many regions the only available constraints on the potential degreeof spatial variability in GHF for much of the continent. In spite of some commonality, there are majordifferences in the currently available geophysical estimates of GHF, and this adds uncertainty tocoupled ice sheet and Solid Earth studies (including GIA), as well as hampering our understanding ofthe Antarctic lithosphere and its tectono-thermal evolution. For example, some models predict highGHF in the interior of the West Antarctic Rift System (WARS), beneath parts of the West Antarctic IceSheet, while others favour instead higher GHF beneath the Marie Byrd Land dome (where a potentialhot spot is located) and along the western edge of the WARS and beneath some parts of theTransantarctic Mountains front (where lithosphere delamination may also have occurred). Reconciling these differences is imperative if we are to understand the tectono-thermal processes thataffected the WARS and ultimately its current state, and subsequently assess its influence on severalhighly dynamic and potentially unstable sectors of the WAIS, including in particular the AmundsenSea Embayment. Equally important, is getting a better handle on the regional and more local-scalevariability with respect to the generally lower background values of the composite East Antarcticcraton. This includes assessing intra-crustal GHF variations linked to its different cratons and orogenicbelts and their overlying basins (e.g. Wilkes, Aurora, Recovery and Pensacola-Pole basins) that haverecently received heightened international attention because of their influence on the stability of theEast Antarctic Ice Sheet.