VSP Data over a Salt Diapir

To test the idea of migrating the PS transmitted waves I generated synthetic data for a salt diapir model with a homogeneous background velocity (Figure ). The traces in Figure  were generated with UTAM's psvr4.f forward modeling code which uses a finite differencing scheme to solve the 2D elastic wave equation. I placed a source far below the surface (520 m) to avoid attenuation due to the absorbing boundary condition of the forward modeling code. The background velocity is modeled at 3000 m/s and the salt is modeled ant 5000 m/s. A P/S velocity ratio of 2.2 is assumed to be constant and equal for both the background and salt media. Figure , Figure , and Figure show three snapshots of the wavefronts to illustrate the presence and strength of the PS transmitted wave. These snapshots are taken at 0.4, 0.7 and 0.8 seconds respectively.