Guang‐Jie Wang

Multi-component wavefield simulation in viscous extensively dilatancy anisotropic media

Abstract A finite difference method for the simulation of multi-component wavefield in viscous extensively dilatancy anisotropic (EDA) media is presented. Transformation of the stress and strain relation from frequency domain to time domain reveals that the viscous effect in EDA media is embedded into the terms of the third derivatives of the strain with respect to time. Numerical examples for viscous EDA media with dry and saturated cracks are calculated, respectively. In the calculation of the wavefields, the absorbing boundary conditions are used to suppress the artificial boundary reflection, the grid dispersion is suppressed by flux corrective transformation (FCT) technique. Snapshots and seismic records show that the existence of cracks and the material contents in the cracks exhibits significant influences on the wave propagation, especially on the radiation pattern and attenuated factor.

The 3-D structure of shear wave in South China and the southward extension of Tanlu fault

By processing the CSND Rayleigh wave data with the matched filter FTAN technique, Rayleigh wave dispersion for southeast China is obtained. The 4∘ × 4∘S wave dispersion of the pure path is calculated using random inversion scheme, and 3-D S wave velocity structure is set up. Incorporating the above-mentioned results with wide angle seismic sounding data, we studied structure framework and the extending of faults in this area, which demonstrates that the depth of Moho in South China varies from 30 to 40 km, shallower from west to east. The depth of Moho varies from 25 to 28 km for the offshore. The depth of the asthenosphere in upper mantle varies from 60 to 100 km. The depth difference of layers at the two sides of Tanlu fault is more than 10 km at the south part of the Yangtze River, and the fault extends downward more than 170 km. The fault exceeds the main land at Hainan Island and slips into the southern China Sea. Both Tanlu fault and the huge bend of gravity gradient anomaly are influenced by deep latent tectonics.