Abstract Using 1 190 local earthquake events recorded by 182 permanent stations from October 2008 to December 2017, we apply the double-difference tomography method to relocate seismic events and invert 3-D seismic velocity structure of Yishu fault zone and adjacent areas. The tomography results show that the P-wave velocity structure of Yishu fault zone has significant inhomogeneity and obvious segmentation features. The upper and middle crust of Tancheng and Juxian has low velocity anomalies. The velocity of Jiaonan block is generally lower than Luxi block. The upper and middle crust of the Taishan area in Luxi block basically shows high-velocity structures. In terms of seismicity, most earthquakes occur in low-velocity structures or transition zones between high-speed zones and low-speed zones with a depth of 5 to 20 km. The brittle rock is easy to rupture under the effect of upper mantle heat upwelling, which causes the deep stress to be transmitted to the crust, and then leads to the shallow earthquakes.
LIU Chengyu,ZHANG Zhengshuai,LI Guoyi. Crustal Structure beneath the Yishu Fault Zone and Adjacent Areas Revealed by Double-Difference Tomography[J]. jgg, 2022, 42(2): 176-181.
LIU Chengyu,ZHANG Zhengshuai,LI Guoyi. Crustal Structure beneath the Yishu Fault Zone and Adjacent Areas Revealed by Double-Difference Tomography[J]. jgg, 2022, 42(2): 176-181.