PEMODELAN NUMERIK PERAMBATAN GELOMBANG SEISMIK DALAM MEDIUM ANISOTROP MENGGUNAKAN METODE FINITE DIFFERENCE STUDI KASUS : LAPISAN BATUBARA TERSESARKAN DAN DANGKAL-DALAM

• Main Authors: , AGUSTINA ARIYANTI, , Drs. Waluyo, M.Sc., Ph.D.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2014
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/128927/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=69302

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