Single Pass Computation of First Seismic Wave Travel Time in Three Dimensional Heterogeneous Media With General Anisotropy

Abstract

We present a numerical method for computing the first arrival travel-times of seismic waves in media defined by a general Hooke tensor, in contrast with previous methods which are limited to a specific subclass of anisotropic media, such as “tilted transversally isotropic” (TTI) media or “tilted orthorhombic” (TOR) media in Waheed et al. (G 80: 49-58, 2015), Bouteiller et al. (GJlI 212: 1498-1522, 2017). Our method proceeds in a single pass over the discretized domain, similar to the fast marching method, whereas existing methods for these types of anisotropy require multiple iterations, similar to the fast sweeping method. We introduce a new source factorization model, making it possible to achieve third-order accuracy in smooth media. We also validate our solver by comparing it with the solution of the elastic wave equation in a 3D medium with general anisotropy.