Effect of Shear Stress on Shear Wave Splitting: A Laboratory Analysis

Seismic behavior of shear waves passing through an anisotropic media and related velocity changes and variations are new challenges for geo-researchers. Shear wave splitting which is the main known result of passing the shear waves through an anisotropic media can provide very useful information about the characteristic of the anisotropic medium. In this study, the effects of shear stress on shear wave splitting and characteristic of split components like amplitude and frequency spectrum have been compared on a sample from an oil field in South-West Iran. The results of this ultrasonic test on a carbonate sample show that the amplitude of perpendicular component (Normal to the shear stress direction) will increase when we increase the amount of shear stresses. This may be used to detect the orientation of the anisotropies and/or on the other hand with enough information about the anisotropies some characteristic of stress field may be estimated.