A STUDY OF EFFECTS OF THE EARTHS RADIAL ANISOTROPY ON THE TIDAL STRESS-FIELD

Anisotropy of the upper mantle is given by Montagner and Anderson in E arth model ACY400. This is used to construct a radially inhomogeneous multilayered sphere Earth model in the present paper. The anisotropy i s treated as radial and the effects of this on the global stress and d isplacement fields are investigated. As a first step the analytical so lutions to a homogeneous and radially anisotropic shell subjected to b ody forces are derived. The analytical solutions to the whole multilay ered sphere are then obtained in terms of the propagator matrix method . The model sphere is divided into 53 layers, in which 18 layers are a nisotropic, and the global stress and displacement fields due to the t idal attractions are then computed. The results are compared with thos e: of the case without anisotropy. It is found from the comparison tha t whether considering the anisotropy given by ACY400 or not, the tidal stress field is very little affected. Finally, a theoretical investig ation is also made on how the thickness of anisotropic layer and the m agnitude of anisotropy would affect the tidal displacement and stress fields.