From pole to equator to pole, heat from the Earth's interior interacts with surface processes. Large-scale crustal structure, sub-glacial melt distribution, palaeoclimate records, oceanic thermal state, oceanic abyssal circulation and potential field geophysics are just some of the science areas that can benefit from its study. Surface geothermal heat flux provides valuable constraints not only on the thermal structure of the lithosphere and density of radioactive elements in the continental crust but also on the present-day state of the Earth's mantle. The study of geothermal heat flux also has socio-economical applications, in particular the problem of extraction of geothermal energy from the crust.

Major uncertainties in surface geothermal heat flux exist (ice-covered regions, deep parts of the ocean) so it is very important to know geothermal heat flux distribution in these regions (it may control subglacial melting, basal sliding, or oceanic circulation). Uncertainties in surface geothermal heat flux distribution, which is strongly inhomogeneous all over the globe, arise from a large number of factors: mantle plumes, upwellings and downwellings in the mantle, plate tectonics, inhomogeneous thickness of the crust including local topographic effects on the continents in the areas of deep valleys and high mountains, lateral variations in thermal structure of the crust, its geological composition and concentration of radioactive elements in its continental part. We can't disconnect the crust from the mantle because geothermal heat flux is the product of both.

This session includes contributions on all aspects of crustal heatflow and geothermal gradient - measured, modelled and applied.

Invited speaker: Dr Michael Purucker, NASA, Geodynamics Lab