We present a semi-analytical solution for 2D forward modelling of viscoelastic relaxation in a spherical earth model with a nested axisymmetric craton. The present semi-analytical approach provides a model response against which more general numerical algorithms can be validated. Numerically, we model the impact of a high-viscosity craton located below the lithosphere in Fennoscandia on surface vertical and horizontal displacements. In agreement with previous results, we show that a high-viscosity region in the upper mantle can influence surface vertical displacements by the order of 10 percent in magnitude. This effect is much greater for surface horizontal displacements and may change completely the pattern of surface movements.