A point dislocation in a layered, transversely isotropic and self-gravitating Earth – Part III: internal deformation

Abstract

SUMMARYIn this paper, we derive analytical solutions for the dislocation Love numbers (DLNs) and the corresponding Green's functions (GFs) within a layered, spherical, transversely isotropic and self-gravitating Earth. These solutions are based on the spherical system of vector functions (or the vector spherical harmonics) and the dual variable and position matrix method. The GFs for displacements, strains, potential and its derivatives are formulated in terms of the DLNs and the vector spherical harmonics. The vertical displacement due to a vertical strike-slip dislocation and the potential change (nΦ) due to a vertical dip-slip dislocation are found to be special, with an order O(1/n) on the source level and O(n) elsewhere. Numerical results are presented to illustrate how the internal fields depend on the particular type of dislocation. It is further shown that the effect of Earth anisotropy on the strain field can be significant, about 10 per cent in a layered PREM model and 30 per cent in a homogeneous earth model.