3D hybrid ray-FD and DWN-FD seismic modeling for simple models containing complex local structures.

Autor: Opršal, Ivo
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Jazyk: angličtina
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Druh dokumentu: Non-fiction
ISSN: 0039-3169
Abstrakt: Abstract: a1_Hybrid approaches find broad applications wherever all-in-one modelling of source, path, and site effects is too expensive. Our new 3D hybrid approach allows to compute the seismic wavefield in elastic isotropic models containing a complex local structure embedded in a large, but considerably simpler, regional structure. The hybrid modelling is realized in two successive steps. In the 1st step, the ray or discrete wave number (DWN) method is used to compute the seismic wavefield due to the source and simple regional structure. The complex local structure is not present. Thus, the excitation contains the source and regional path effects. The time history of this wavefield (excitation), recorded at the points of so called excitation box, is stored on a disk. The excitation box envelopes a small portion of a computational domain. The 2nd step of the hybrid method, now containing the complex local structure, is computed by finite differences (FD) inside the excitation box and its close vicinity. The excitation from the 1st step is now used to inject the 1st step wavefield into the 2nd step computation. After that, the hybrid combination of the 1st and 2nd steps contains the source, regional path, and local structure effects at reasonably lower computational costs than in case of all-in-one modelling.
Databáze: Katalog Knihovny AV ČR
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