Abstract This paper uses the observation data for the past eight years recorded by fixed and mobile stations of the Xinjiang seismic network in the south Tianshan area. We carry out local earthquake travel time tomography technology to obtain the three-dimensional crustal velocity structure, and use the three-dimensional velocity structure to relocate local earthquake events. After relocation, the root mean square of the travel time residual decreases from 1.29 s to 0.64 s, and the uncertainty of the source location is about 0.1 km. The three-dimensional velocity structure shows that the velocity structure in the region has obvious lateral and vertical inhomogeneities. At 5 km, it is a high-speed anomaly north of the Artux anticline and the Keping fault, a low-speed anomaly in the south. The velocity ratio is dominated by high values on the whole. At the depths of 15 km and 20 km, the P-wave velocity in the study area is dominated by high-speed anomalies. At the depth of 25-30 km, the P-wave high-speed anomalies in the area turn into obvious near north-east with low-speed anomalies, the velocity ratio is also dominated by the low value anomalies in the NNE direction. The seismic activity in the area has a strong correspondence with the crustal velocity structure. The source is mainly concentrated in the high speed region at the junction of high and low P wave velocity. The velocity ratio also tends to the side of the high velocity ratio. There is a low-speed band under the focal area, which provides a strong environmental foundation for the accumulation and release of strain energy.
ZHANG Zhibin,ZHAO Xiaocheng. Three-Dimensional Crustal Velocity Structure in the South Tianshan Mountains, Xinjiang :Results from Local Earthquake Tomography[J]. jgg, 2021, 41(3): 243-248.
ZHANG Zhibin,ZHAO Xiaocheng. Three-Dimensional Crustal Velocity Structure in the South Tianshan Mountains, Xinjiang :Results from Local Earthquake Tomography[J]. jgg, 2021, 41(3): 243-248.
