Determination of parameters of viscoelastic anisotropy from ray velocity and ray attenuation: Theory and numerical modeling

0448564 - GFÚ 2016 RIV US eng J - Journal Article
Vavryčuk, Václav
Determination of parameters of viscoelastic anisotropy from ray velocity and ray attenuation: Theory and numerical modeling.
Geophysics. Roč. 80, č. 3 (2015), C59-C71. ISSN 0016-8033. E-ISSN 1942-2156
R&D Projects: GA ČR(CZ) GAP210/12/1491
Institutional support: RVO:67985530
Keywords : transversely isotropic media * elastic anisotropy * wave propagation
Subject RIV: DC - Siesmology, Volcanology, Earth Structure
Impact factor: 2.017, year: 2015

We have developed and numerically tested a method for determining parameters of homogeneous viscoelastic anisotropy from measurements of wavefields generated by point sources. The method is based on complex algebra and consists of several steps. First, a complex energy velocity surface is constructed from the directionally dependent velocity and attenuation measured along a set of ray directions. Second, a complex slowness surface is computed using the relation of polar reciprocity between the energy velocity and slowness vectors. The energy velocity vectors are homogeneous, but the corresponding slowness vectors are inhomogeneous. Finally, the complex phase velocity surface is calculated and inverted using the Christoffel equation. The inversion is nonlinear and can be performed in iterations. Numerical tests for the P-wave in transversely isotropic media showed that the method performed well for a wide range of models covering strong as well as weak velocity anisotropy and various levels of attenuation.
Permanent Link: http://hdl.handle.net/11104/0250227