The effect of solid tide in geopotential field of an elastic and inelastic earth

Abstract

In this paper the influence of solid tide on the Earth gravity field is considered. In this consideration the Earth can be regarded as either an elastic or inelastic body. Each one of these elastic and inelastic bodies has two main tidal components, frequency dependent and frequency independent components. In this article how to compute the effect of these components in the Earth's gravity field is presented. In this investigation, an attempt is made to find out whether the Earth should be regarded as an elastic or inelastic body in practical applications. Computations show equivalent effects on the gravity field due to the elastic and inelastic Earth model. The effect of the frequency dependent component of solid tide due to the elastic and inelastic Earth is much smaller than the frequency independent components. It depends on time and tidal constituents and it should be considered in precise applications. Comparisons between the solid tides due to the elastic and inelastic Earth model show that the inelastic Earth is contracted at poles about 3 mm and expanded at equator about 2.5 mm more than the elastic case.