Geoidal Topography: Origin and Time Consistency

Abstract

The geoid topography is a direct measure of the irregular density distribution within the Earth. Hence, the geoid is an important tool in deciphering the internal structures and conditions. Deformations of the geoid — i.e. the mean sea level — with time, therefore, give evidence of density changes within the Earth. Past sea level changes that can be shown not to originate from tectonic processes, changes in the oceans’ water volume, changes in the oceans’ basin volumes or local dynamic sea level effects are found to represent paleo-geoid changes (Mörner, 1976, 1981a, 1983a). Such paleogeoid changes have now been identified for time units ranging from a few years to several million years (Mörner, op. cit.). This gives evidence of rapid processes within the Earth changing the density distribution; i.e. it gives evidence of a high-dynamic Earth.