Inversion of Site Velocity Structure Based on Near-field Seismic Records at Single Station
The P-wave seismogram method offers a fast and convenient approach to investigating the velocity structure at seismic stations using near-field strong aftershock records,thus maximizing the utility of these data.This method was thoroughly derived,and its inversion objective function was analyzed.Through numerical simulations of theoretical seismograms from multiple near-field sites,the impact of site characteristic parameters and seismic source duration on the delay between the PS-wave and P-wave was examined.The applicability of the seismic records was also assessed.To improve the single-station seismogram method,the amplitude ratio between the initial vertical and radial components at the first arrival of the P-wave was incorporated as an additional inversion objective function.The improved method was then applied to invert the S-wave velocity structure at the Wudu station using mainshock and aftershock records from the Wenchuan earthquake.Comparisons with the surface wave method and the borehole method demonstrate that the enhanced single-station seismogram method improved search capability,as well as inversion efficiency and accuracy.
万方数据
维普
