HR: 0830h
AN: S11F-0358    [PDF]
TI: Quasi-Cylindrical FDM: an Ultra-Fast 2.5D Waveform Modeling Method for Explosion Seismic Experiments
AU: * Takenaka, H
EM: takenaka@geo.kyushu-u.ac.jp
AF: Dept. of Earth Planet. Sci., Kyushu Univ., Hakozaki 6-10-1, Fukuoka, 812-8581 Japan
AU: Tanaka, H
EM: hiroki.ta-na@docomo.ne.jp
AF: Sakata Weather Station, JMA, Kamegasaki 1-4-14, Sakata, 998-0842 Japan
AU: Okamoto, T
EM: taro@geo.titech.ac.jp
AF: Dept. of Earth Planet. Sci., Tokyo Inst. Tech., Ookayama 2-12-1, Meguro, Tokyo, 152-8551 Japan
AU: Kennett, B L
EM: brian@rses.anu.edu.au
AF: RSES, Australian National Univ., Mills Road, Canberra, ACT 0200 Australia
AB: We propose a new efficient method for modeling 2.5D wavefields of explosion seismic surveys. The most common form of seismic exploration remains a nearly linear survey with data acquisition lines including the source and receivers. The interpretation of amplitude and waveform information for such linear acquisition requires consideration of 3D seismic wavefields. In many scenarios the structure is approximately 2D, but still modeling is needed for point sources. Recently 2.5D modeling methods have been developed for the simulation of 3D seismic wavefields in media varying in two dimensions, which require a storage only slightly larger than those of the corresponding 2D calculations. However, they require long computation times comparable to that of the corresponding 3D calculations, which is a major obstacle in routinely applying these conventional 2.5D methods to seismic surveys. To overcome this computation time problem, we have considered a new approach for modeling 2.5D seismic wavefields using a quasi-cylindrical representation, and implemented this approach using a velocity-stress finite-difference method (FDM). Our method requires similar computation time and storage as for 2D calculations, so that, with moderate computational resources, we may apply the method to routine analysis of seismic surveys where a number of trials of waveform modeling are inevitable. In this presentation we show some numerical examples to demonstrate the validity and feasibility of our method, with a simulation of a realistic large-scale onshore-offshore seismic experiment.
DE: 0902 Computational methods, seismic
DE: 3230 Numerical solutions
DE: 7203 Body wave propagation
DE: 7205 Continental crust (1242)
DE: 7260 Theory and modeling
SC: Seismology [S]
MN: 2003 Fall Meeting