HR: 1340h
AN: S13D-1078 [Abstracts]
TI: Quasi-Spherical Approach: A Fast Method for Modeling of Seismic Wave Propagation in a 2D Slice of a
Global Earth Model With Lateral Heterogeneity
AU: * Toyokuni, G
EM: toyokuni@geo.kyushu-u.ac.jp
AF: Department of Earth and Planetary Sciences, Kyushu University, 6-10-1 Hakozaki, Fukuoka, 812-8581
Japan
AU: Takenaka, H
EM: takenaka@geo.kyushu-u.ac.jp
AF: Department of Earth and Planetary Sciences, Kyushu University, 6-10-1 Hakozaki, Fukuoka, 812-8581
Japan
AU: Wang, Y
EM: ybwang@pku.edu.cn
AF: Department of Geophysics, Peking University, Haidian District, Beijing, 100871
China
AU: Kennett, B L
EM: brian@rses.anu.edu.au
AF: Research School of Earth Sciences, Australian National University, Mills Road, Canberra, ACT 0200
Australia
AB:
We propose a new method for calculation of seismic wavefield
propagating in a global earth model includes lateral heterogeneity. In
the field of global waveform modeling, 2D or axisymmetric modeling has
been used because full 3D modeling is too intensive for real application.
Considering 2D modeling cannot correctly model 3D geometrical spreading
effects, axisymmetric modeling is the most appropriate method for
global seismology. However, axisymmetric modeling couldn't treat
unaxisymmetrical structure with respect to the source axis.
Furthermore the scattered and reflected waves from the symmetric
continuation of the structure can be returned to the target zone as
artificial numerical noise.
In order to overcome these problems, we here propose
an ultra efficient approach for modeling 3D elastic wavefield. We
solve the elastodynamic equation for spherical coordinates not in
the conventional spherical domain:
$(0
DE: 7200 SEISMOLOGY
SC: Seismology [S]
MN: 2004 AGU Fall Meeting