A first-order qP-wave propagator in 2D VTI media

He Liu, Kristopher A. H. Innanen

In a vertical transversely isotropic (VTI) medium, quasi-P (qP) and quasi-SV (qSV) waves are intrinsically coupled as described in elastic wave equations. Therefore, when we perform elastic reverse time migration and imaging processes to qP-waves, qSV-wave energy will introduce crosstalk noise to the imaging results. Many authors have proposed to separate qP-waves from elastic waves for better imaging results. As an alternative way, some authors have proposed to directly simulate qP-waves with modified elastic wave equations. In this study, we develop a first-order wave propagator of pseudo-pure-qP-wave in 2D heterogeneous VTI media using staggered-grid scheme. We have performed this algorithm to simulate P-waves propagating in an isotropic medium, VTI media with weak/strong anisotropy and a two-layer VTI model, the synthetic results validate the feasibility of this algorithm. Also, we adopt the first-order Hybrid-PML in the simulation, which helps the simulation efficiency due to its better performance for anisotropic media.