Generation of 6-C synthetic seismograms in stratified vertically transversely isotropic media using a generalized reflection and transmission coefficient method. Issue 3 (3rd February 2021)

• Record Type: Journal Article
• Authors: Tang, Le; Fang, Xinding
• Is Part Of: Geophysical journal international. Volume 225:Issue 3(2021)
• Page Start: 1554
• Page End: 1585
• Publication Date: 2021-02-03
• Subjects: Computational seismology -- Rotational seismology -- Seismic anisotropy; Geophysics -- Periodicals; 550
• DOI: 10.1093/gji/ggab044
• Languages: English
• ISSNs: 0956-540X

Abstract

SUMMARY: We develop a generalized reflection and transmission coefficient method (GRTM) for generating six-component (6-C) synthetic seismograms in horizontally layered vertically transversely isotropic (VTI) media. Compared with the traditional seismic modelling approaches that only consider translational motion, our method can simultaneously produce three-component translational and three-component rotational data excited by a point vector force or a moment tensor source in a layered half-space. Horizontally layered models are widely used in near surface applications as the properties of near surface formations generally show small lateral variations and change mainly along the depth direction. The use of the VTI constitutive relation can make our method applicable to more general situations because it takes into account the characteristics of sedimentary formations. We compare our method with a finite-difference method (FDM) for a variety of velocity models and acquisition geometries. The numerical results demonstrate that accurate 6-C synthetic seismograms can be calculated using our method. The computational efficiency of our method for 6-C seismic modelling is much higher than the finite-difference method, because it can reduce a 3-D modelling problem to 2.5-D by eliminating the azimuthal dimension. Also, our method does not require to perform additional spatial interpolations to obtain the rotational components. These advantages make our method suitable to serve as a forward modelling tool for rotational seismology.