Understanding and modeling seismic wave propagation is important in regional and
exploration seismology. Ray tracing is a powerful and popular method for this purpose.
Wavefront construction (WFC) method handles wavefronts instead of individual
rays, thereby controlling proper ray density on the wavefront. By adaptively controlling
rays over a wavefront, it efficiently models wave propagation. Algorithms for a
quasi-P wave wavefront construction method and a new coordinate system used to
generate wavefront construction mesh are proposed and tested for numerical properties
and modeling capabilities. Traveltimes, amplitudes, and other parameters, which
can be used for seismic imaging such as migrations and synthetic seismograms, are
computed from the wavefront construction method. Modeling with wavefront construction
code is applied to anisotropic media as well as isotropic media. Synthetic
seismograms are computed using the wavefront construction method as a new way
of generating synthetics. To incorporate layered velocity models, the model based
interpolation (MBI) ray tracing method, which is designed to take advantage of the
wavefront construction method as well as conventional ray tracing methods, is proposed
and experimental codes are developed for it. Many wavefront construction
codes are limited to smoothed velocity models for handling complicated problems
in layered velocity models and the conventional ray tracing methods suffer from the
inability to control ray density during wave propagation. By interpolating the wavefront
near model boundaries, it is possible to handle the layered velocity model as well
as overcome ray density control problems in conventional methods. The test results
revealed this new method can be an effective modeling tool for accurate and effective
computing.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/3771 |
| Date | 16 August 2006 |
| Creators | Lee, Kyoung-Jin |
| Contributors | Gibson, Richard L. Jr. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 18138293 bytes, electronic, application/pdf, born digital |
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