1 He Y M, Wen L X, Zheng T Y. Geographic boundary and shear wave velocity structure of the “Pacific anomaly” near the core-mantle boundary beneath western Pacific. Earth Planet Sci Lett, 2006, 244: 302-314？？
[2]
2 Ni S D, Helmberger D V, Tromp J. Three-dimensional structure of the African superplume from waveform modeling. Geophys J Int, 2005, 161, doi: 10.1111/j.1365-246X.2005.02508.x
[3]
22 Kosloff D, Reshef M, Loewenthal D. Elastic wave calculation by the Fourier method. Bull Seismol Soc Amer, 1984, 74: 875-891
[4]
23 Fornberg B. The pseudospectral method: Accurate representation of interfaces for elastic wave calculations. Geophysics, 1988, 53: 625-637？？
[5]
24 Herrmann R B. SH-wave generation by dislocation source—A numerical study. Bull Seismol Soc Amer, 1979, 69: 1-15
[6]
25 Cerjan C, Kosloff D, Kosloff R, et al. A nonreflecting boundary condition for discrete acoustic and elastic wave equations. Geophysics, 1985, 50: 705-708？？
[7]
26 Daudt C R, Braile L W, Nowack R L, et al. A comparison of finite-difference and Fourier method calculations of synthetic seismograms. Bull Seismol Soc Amer, 1989, 79: 1210-1230
[8]
3 Wang Y, Wen L X, Weidner D, et al. SH velocity and compositional models near the 660-km discontinuity beneath South America and northeast Asia. J Geophys Res, 2006, 111: B07305, doi: 10.1029/2005JB003849.
[9]
4 Wang T, Chen L. Distinct velocity variations around the base of the upper mantle beneath northeast Asia. Phys Earth Planet Inter, 2009, 172, doi: 10.1016/j.pepi.2008.09.021
6 Cummins P R, Takeuchi N, Geller R J. Computation of complete synthetic seismograms for laterally heterogeneous models using the Direct Solution Method. Geophys J Int, 1997, 130: 1-16？？
[12]
7 Takeuchi N, Geller R J, Cummins P R. Complete synthetic seismograms for 3-D heterogeneous Earth models computed using modified DSM operators and their applicability to inversion for Earth structure. Phys Earth Planet Inter, 2000, 119: 25-36？？
[13]
8 Komatitsch D, Tromp J. Spectral-element simulations of global seismic wave propagation—I. Validation. Geophys J Int, 2002, 149: 390-412？？
[14]
9 Komatitsch D, Tromp J. Spectral-element simulations of global seismic wave propagation—II. Three-dimensional models, oceans, rotation and self-gravitation. Geophys J Int, 2002, 150: 303-318？？
11 Igel H, Weber M. SH-wave propagation in the whole mantle using high-order finite differences. Geophys Res Lett, 1995, 22: 731-734？？
[17]
12 Igel H, Weber M. P-SV wave propagation in the Earth''s mantle using finite differences: Application to heterogeneous lowermost mantlestructure. Geophys Res Lett, 1996, 23: 415-418？？
[18]
13 Igel H, Gudmundsson O. Frequency-dependent effects on travel times and waveforms of long-period S and SS waves. Phys Earth Planet Inter, 1997, 104: 229-246？？
[19]
14 Nissen-Meyer T, Fournier A, Dahlen F A. A 2-D spectral-element method for computing spherical-earth seismograms—I. Moment-tensor source. Geophys J Int, 2007, 168: 1067-1093？？
[20]
15 Thorne M S, Lay T, Garnero E J, et al. Seismic imaging of the laterally varying D″ region beneath the Cocos Plate. Geophys J Int, 2007, 170: 635-648, doi: 10.1111/j.1365-246X.2006.03279.x？？
[21]
16 Jahnke G, Thorne M S, Cochard A, et al. Global SH-wave propagation using a parallel axisymmetric spherical finite-difference scheme: Application to whole mantle scattering. Geophys J Int, 2008, 173: 815-826, doi: 10.1111/j.1365-246X.2008.03744.x？？
[22]
17 Toyokuni G, Takenaka H, Wang Y, et al. Quasispherical approach for seismic wave modeling in a 2D slice of a global Earth model with lateral heterogeneity. Geophys Res Lett, 2005, 32, doi: 10.1029/2004GL022180
[23]
18 Toyokuni G, Takenaka H. FDM computation of seismic wavefield for an axisymmetric earth with a moment tensor point source. Earth Planets Space, 2006, 58: e29-e32
[24]
19 Fornberg B. The pseudospectral method: Comparisons with finite-differences for the elastic wave equations. Geophysics, 1987, 52: 483-501？？
[25]
20 Furumura T, Kennett B L N, Furumura M. Seismic wavefield calculation for laterally heterogeneous whole earth models using the pseudospectral method. Geophys J Int, 1998, 135: 845-860？？
[26]
21 Wang Y B, Takenaka H, Furumura T. Modelling seismic wave propagation in a two-dimensional cylindrical whole-earth model using the pseudospectral method. Geophys J Int, 2001, 145: 689-708？？
[27]
27 Graves R W. Simulating seismic wave propagation in 3D elastic media using staggered-grid finite differences. Bull Seismol Soc Amer, 1996, 86: 1091-1106
[28]
28 Dziewonski A M, Anderson D L. Preliminary reference earth model. Phys Earth Planet Inter, 1981, 25: 297-356？？
[29]
29 Helmberger D V, Vidale J E. Modeling strong motions produced by earthquakes with two-dimensional numerical codes. Bull Seismol Soc Amer, 1988, 78: 109-121
