3-D frequency-domain seismic wave modelling in heterogeneous, anisotropic media using a Gaussian quadrature grid approach

dc.contributor.authorZhou, B.
dc.contributor.authorGreenhalgh, S.
dc.date.issued2011
dc.description.abstractWe present an extension of the 3-D spectral element method (SEM), called the Gaussian quadrature grid (GQG) approach, to simulate in the frequency-domain seismic waves in 3-D heterogeneous anisotropic media involving a complex free-surface topography and/or sub-surface geometry. It differs from the conventional SEM in two ways. The first is the replacement of the hexahedral element mesh with 3-D Gaussian quadrature abscissae to directly sample the physical properties or model parameters. This gives a point-gridded model which more exactly and easily matches the free-surface topography and/or any sub-surface interfaces. It does not require that the topography be highly smooth, a condition required in the curved finite difference method and the spectral method. The second is the derivation of a complex-valued elastic tensor expression for the perfectly matched layer (PML) model parameters for a general anisotropic medium, whose imaginary parts are determined by the PML formulation rather than having to choose a specific class of viscoelastic material. Furthermore, the new formulation is much simpler than the time-domain-oriented PML implementation. The specified imaginary parts of the density and elastic moduli are valid for arbitrary anisotropic media. We give two numerical solutions in full-space homogeneous, isotropic and anisotropic media, respectively, and compare them with the analytical solutions, as well as show the excellent effectiveness of the PML model parameters. In addition, we perform numerical simulations for 3-D seismic waves in a heterogeneous, anisotropic model incorporating a free-surface ridge topography and validate the results against the 2.5-D modelling solution, and demonstrate the capability of the approach to handle realistic situations.
dc.description.statementofresponsibilityBing Zhou and S. A. Greenhalgh
dc.identifier.citationGeophysical Journal International, 2011; 184(1):507-526
dc.identifier.doi10.1111/j.1365-246X.2010.04859.x
dc.identifier.issn0956-540X
dc.identifier.issn1365-246X
dc.identifier.urihttp://hdl.handle.net/2440/68315
dc.language.isoen
dc.publisherBlackwell Publishing Ltd
dc.relation.grantARC
dc.rights© 2010 The Authors. Geophysical Journal International © 2010 RAS
dc.source.urihttps://doi.org/10.1111/j.1365-246x.2010.04859.x
dc.subjectNumerical solutions
dc.subjectbody waves
dc.subjectseismic anisotropy
dc.subjectseismic tomography
dc.subjectcomputational seismology
dc.subjectwave propagation
dc.title3-D frequency-domain seismic wave modelling in heterogeneous, anisotropic media using a Gaussian quadrature grid approach
dc.typeJournal article
pubs.publication-statusPublished

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