A Method for Calibrating Australian Temperature-Depth Models

Abstract

The Australian geothermal industry is moving rapidly, and in that process requires a lot from geophysics to aid in characterising regional prospectivity for exploitable heat resources. Various groups are using hybrid methods to estimate ‘Curie point’ temperatures at depth, or alternatively, the temperature at 5 kilometres below the surface. Deep drilling observations and airborne magnetic compilations are the key components, together with a basement geology interpretation. Several generations of this work are already published with more to come. A method to test these maps and also help characterise uncertainty is proposed based upon a deep 3D continental model scale, extending to the lithosphere. Variable surface temperature and heat flow grids, based upon remote sensing are used, together with a simple lithosphere boundary condition. The heat diffusion is then employed to test the temperature-depth maps. Progress on applying this method to Australia is reported.