The elastic residual field of a very long strike-slip fault in the presence of a discontinuity

On the basis of dislocation theory, formulas for the elastic residual field of a long strike-slip fault in a half-space with a vertical and horizontal discontinuity are given. The obtained results are applied to the 1966 Parkfield-Cholame earthquake. There is good agreement between the calculated residual stress field and the distribution of aftershocks. The influence of an underlying layer on the residual-surface displacements and strains of a long, vertical strike-slip fault located in the surface layer was found. Both displacements and strains diminish faster as a function of distance from a fault in the presence of a more rigid underlying layer. The computed results show that the dislocation model of a fault in a homogeneous half-space can be inadequate in many cases.