Thermoelastic stresses and strains in a gravitating earth

Summary The stress and strain fields in various earth models are studied under the assumption of an elastic mantle and the existence of thermal stresses which are proportional to the difference between the initial and present temperatures. The thermoelastic equilibrium equation for a 49-layered earth with spherical symmetry is integrated and programmed for various combinations of velocities, densities and temperatures. Results show that the strains in the upper mantle depend to a great extent on the thermal model. Central radial strain ranges from 5.2 to 7.3 per cent and the central pressure ranges between 3.1 and 3.7×10¹² dynes/cm² for all models. It is established that the thermal history of the earth could not have changedBullen's pressures by more than 0.4×10¹² dynes/cm².Contribution No. 1095, Division of Geological Sciences, California Institute of Technology, Pasadena, California.