Fundamental study for estimating azimuthal shear wave anisotropy by applying VSM in marine airgun survey

Abstract

In this study we utilize the virtual source method to overcome existing problems surrounding marine shear wave survey. We improve the virtual source method (VSM) to enable to generate shear wave signal even in marine survey by using airgun records and a single ocean bottom seismometer (OBS). To evaluate this method, we conduct numerical experiments by using 3D finite difference simulation including an azimuthal anisotropic layer. We generate virtual 4C data by using our VSM and estimate azimuthal direction in subsurface of the model by applying the Alford rotation to these virtual 4C data with reasonable accuracy.