On the use of the volumetric thermal expansion coefficient in models of ocean floor topography

Abstract

The use of the volumetric thermal expansion coefficient, instead of the linear coefficient, in successful models of ocean floor topography implies that the elastic rigidity of the lithosphere relaxes, enabling isostasy to be achieved. However, the presence of a thin elastic lid in the lithosphere, inferred from gravity investigations, implies some rigidity at the top of the lithospheric column and suggests that the volumetric thermal expansion coefficient derived from rheologically uniform models of the topography is about 15% too small.