Proxy Heat Flux and Magnetisation Model from Satellite Magnetic Data

摘要

From the Curie isotherm depths derived from the aeromagnetic data, the geothermal heat flux was calculated utilizing the 1D heat conduction, steady state thermal model for the continental crust. Available values of the surface heat-production and thermal conductivity for the various tectonic blocks of India are incorporated for computing the heat flux. The calculated heat flux for several areas matches reasonably well with the surface heat flow measurements. As the aeromagnetic data coverage over India is limited, the heat flux for the Indian region is calculated using magnetic crustal thickness derived from MF5 lithospheric model of CHAMP satellite data utilizing an iterative forward modelling approach assuming a constant susceptibility contrast for the ocean and continents. Higher heat flux are observed over the mobile belts and rift zones while lower heat flux are observed over the cratons. Further, a Vertical Integrated Susceptibility (VIS) model incorporating both Curie depths from the aeromagnetic data together with realistic susceptibility values is used to better reproduce the observed satellite data. With the upcoming multi satellite high-resolution SWARM data the lithospheric models would be superior; and these maps could be effectively used to reconstruct the thermal regime of the continents.