Abstract

The present study is an investigation of the thermal history of the earth using heat transfer modeling. Assuming that the earth was a hot ball at a homogeneous temperature upon its formation, the model makes the following two predictions about conditions 4.5 Ga later (the earth's approximate present age): (i) there will be a geothermal gradient within a range of 1.5-5.0 C per 100 meters in the first km of the earth crust; and (ii) the earth's crust will be about 45 km thick, which is in agreement with average continental crust thickness. The fact that oceanic crust is much thinner (around 5-10 km thick) is explained by convective heat transfer and plate tectonics. The strong agreement between the predicted thicknesses of earth's crust with the average actual continental crust thickness helps confirm the accuracy of the current inner core model of the earth indicating a solid inner core made of iron based on seismological studies.

Keywords: Thermal history; Homogenous temperature; Earth crust; Core; Geothermal gradient