Derrick Hasterok1, Matthew Gard1, Samuel Jennings1
1University Of Adelaide, Adelaide, Australia
Fifty years ago isostatic subsidence was proposed as a method to investigate the thermal state of the oceanic lithosphere. But it has always been more difficult to use isostatic methods on the continents due to significantly larger variations in composition, crustal thickness, and thermal properties (i.e., thermal conductivity and heat production). The development of continent-wide seismic models of velocities and crustal thickness in recent years combined with laboratory-constrained models of physical properties as a function of composition allow for sufficiently accurate estimates of compositional buoyancy to reveal the thermal contribution to elevation. As a result isostatic methods applied to North America and Australia have shown great potential for improving estimates of the thermal state, particularly if heat production and/or sublithospheric heat flux can be constrained independently. In this study, we will discuss the potential—and pitfalls—for applying thermal isostatic methods to predict the thermal state beneath the Antarctica ice sheet. We will review previous constraints on the thermal state of the Antarctic lithosphere, and how these can be used with new estimates of crustal heat production and thermal conductivity to conduct thermal isostatic analysis.