Geoid heights due to a crustal low viscosity zone in glacial isostatic adjustment modeling: A sensitivity analysis for GOCE

Abstract

Seismic observations and the occurrence of postseismic deformation in several continental regions indicate the presence of one or more layers with relative low (1018 1019 Pas) viscosity in the Earth's crust. This study simulates the effect of thickness, viscosity and depth of such a low viscosity zone (LVZ) on geoid heights that are the result of glacial isostatic adjustment to Pleistocene ice loads. It is found that an LVZ introduces variations in geoid heights up to 1 meter with spactial scales larger than a few hundred kilometers underneath and just outside former glaciated areas. The response to changes in the properties of the LVZ is shown to be wavelength-dependent. The LVZ induced geoid signal is within the accuracy of the upcoming GOCE satellite mission, which means that in principle it should be possible to detect the presence of a supposed LVZ with GOCE data. Copyright 2004 by the American Geophysical Union.