Abstract:We focus on the southeastern margin of Qinghai-Tibet plateau, which presents weak distribution characteristics and spatial characteristics of seismicity, and put forward the crust-mantle coupling model of strong earthquake gestation. Using data collected from the China National Digital Seismic Network in Yunnan and Sichuan Regional Digital Seismic Network, and setting in the southeastern margin of Qinghai-Tibet plateau seismic stations teleseismic records by SKS waveform data, through the upper mantle anisotropy results for the shear wave splitting data, we describe the southeastern margin of Qinghai-Tibet plateau in the upper mantle anisotropy images. Then, we carry out correlation processing and analysis respectively with the velocity field data observed by GPS in this area, the data of regional tectonic stress field,and the medium density data at a depth of 13 km. The proposed model is verified to a certain extent. Analysis results show that through the research on the coupling characteristics of the deformation field and stress field, and the anisotropy of fast wave polarization direction with the direction of GPS crustal movement velocity field changes, the maximum stress direction and level of the overall correlation is larger, the mutual effects among various spheres of crust-mantle and asthenosphere shown on the flow of seismic anisotropy are closely related to the stress transfer mechanism. At the same time, we can also get the key role of weak zone(low speed and high conductor) in the study of coupled crust-mantle motion through correlation analysis.
HOU Qiang,YAO Yafeng,OU Minglin et al. Crust-Mantle Coupling Model for Seismogenism in the Southeastern Margin of Qinghai-Tibet Plateau[J]. jgg, 2019, 39(12): 1211-1222.