Effects of generally anisotropic crustal rocks on fault-induced displacement and strain fields

Abstract

We present a new solution for the elastic displacement and strain fields on or near Earth's surface due to rectangular faults in an anisotropic half-space, expressed as a summation of (A) the solution in an infinite space which is singular, and (B) the complementary part which is regular and well-behaved. These two solutions are expressed in terms of the mathematically elegant and computationally powerful Stroh formalism and can be applied to the generally anisotropic rock half-space or a transversely isotropic rock mass with any oriented plane of isotropy. For any flat fault of polygonal shape, one needs only to carry out a simple line integral from 0 to π in order to express the fault-induced response. Numerical examples are presented to demonstrate the significant effect of the rock anisotropy and layer orientation on the fault-induced displacement and strain fields in anisotropic rocks. Potential applications are wide ranging, from faults in sedimentary strata to strongly deformed metamorphic rocks with steeply dipping foliation.