Static Deformation Due to Shear and Tensile Faults in a Layered Half-Space

Based on the generalized reflection and transmission coefficient matrix method, formulations for surface static displacements in a layered half-space are extended to include tensile and inflation point sources from a point pure shear dislocation source. Equations for calculating internal displacement fields from these sources are also derived. The validity of the formula and precision of the new method are illustrated by comparing the consistency of our results and the analytical solutions given by Okadaʹs (1985, 1992) code in a homogenous half-space and Wang et al.ʹs (2003) numerical solutions in a multilayered half-space. We also study the effect of a layered half-space on the surface displacement created by various finite faults. Several typical velocity structures in reality are selected. For strike-slip, reverse dip-slip, and tensile finite-fault models, the focal depth is very sensitive to the presence of the layered model. The slip displacement is more sensitive to the layered model in the case of the normal dip-slip sources. More numerical tests show that the sensitive slip is mainly due to the ultralow-velocity topsoil. For inflations, the source depth and volume change also altered due to the layered model.