Gravitational viscoelastic relaxation of eccentrically nested spheres

We present a semi-analytical solution to the 2-D forward modelling of visco elastic relaxation in a heterogeneous model consisting of eccentrically nes ted spheres. Several numerical methods for 2-D and 3-D viscoelastic relaxat ion modelling have been applied recently, including finite-element and spec tral-finite-difference schemes. The present semi-analytical approach provid es a model response against which more general numerical algorithms can be validated. The eccentrically nested sphere solution has been tested by comp aring it with the analytical solutions for viscoelastic relaxation in a hom ogeneous sphere and in two concentrically nested spheres, and good agreemen t was obtained.