| Summary: | The crustal rocks in the earth are mostly anisotropic medium. However, they
are usually assumed to be isotropic because isotropy modelling is much simpler
than anisotropy. There are different characters on every direction of seismic wave
propagation in anisotropic medium. On the other hand, anisotropy modelling
requires more parameter and more complicated calculation than isotropy.
Nevertheless, anisotropy modelling is needed to produce more realistic seismic
data. A computer program of seismic wave propagation in 2D anisotropic medium
was carried out using staggered-grid fourth order finite difference method by
MATLAB. This program was verified by comparing the seismogram with the
analytical result. Then this program was applied in two models of coal bed, which
are faulted and shallow-deep coal beds. Both of the models were built to be
anisotropic and isotropic medium. Anisotropic coal bed indicated that there are
differences between arrival times of seismic wave in both medium. This condition
could influence processing and interpretation of seismic data result. Anisotropic
medium produced higher AVO and wave dispersion effect than isotropic medium.
Keywords: anisotropy, isotropy, finite difference, seismic wave
|
|---|