Accumulation of Stress and Strain due to an Infinite Strike-Slip Fault in an Elastic Layer Overlying a Viscoelastic Half Space of Standard Linear Solid (SLS)

Viscoelastic behaviour of materials at the lithosphere-asthenosphere boundary is observed in this paper. The observed post-seismic and aseismic deformation help us to understand the rheological properties of the mantle and asthenosphere. A quasi-static model having homogeneous, isotropic, elastic material overlying viscoelastic material of a standard linear solid (SLS) is considered. A long strike-slip fault of finite width inclined to the free surface due to a sudden movement has been studied in this work. Analytical solutions for displacement, stresses and strains are obtained before and after fault movement using a technique involving the use of Green's functions and integral transforms, assuming that tectonic forces maintain a shear strain far away from the fault. The effect of aseismic fault movement across it is found to depend on distance, dimension, relative position and other characteristics of the fault. Also, the effect of different inclinations, elastic layer thickness and slip magnitude have been studied. The study of such earthquake fault dynamical model helps us to understand the mechanism of the lithosphere-asthenosphere boundary.