Eigenvibrations of the Earth Excited by Finite Dislocations-I1 Spheroidal Oscillations

The expansion of the normal mode Green’s dyad for a radially hetero-geneous, self-gravitating, elastic sphere is obtained in terms of vector spherical harmonics. The Volterra relation is employed to compute the relative amplitudes of the spheroidal oscillations of the sphere excited by a tangential or a tensile dislocation of arbitrary size and orientation. Explicit expressions for the strains, stresses and tilts at the free surface of the sphere are derived in a form suitable for numerical calculations. The problem of a dislocation source in a vertically heterogeneous elastic half-space is also discussed. 1