Abstract:
In this paper, the shear wave splitting parameters of 23 seismic stations in Weiyuan area, Sichuan are obtained using the shear wave splitting analysis method, base on the local earthquake waveform data recorded by the temporary seismic stations from November 2019 to May 2020 in the study area. The results show that the polarization directions of fast shear wave at most stations in Weiyuan area are northwest, which is consistent with the direction of regional principal compressive stress. And the polarization directions of a few stations are northeast, which may be affected by the local tectonic environment. Near Weiyuan anticline with obvious differences in crustal velocity, there are six stations with two dominant polarization directions of fast wave, indicating that the polarization direction of fast wave in this area is influenced by the combined effects of regional stress field and local tectonic environment. The average delay time of slow wave in Weiyuan area is 4.43 ms/km. And the delay time of slow wave in the south of Weiyuan anticline is generally greater than that in the north, suggesting that the anisotropy intensity in the south of Weiyuan area is stronger than that in the north.