Inversion of GPS data for slip rates and locking depths of the Haiyuan fault
Cui Duxin Wang Qingling Hu Yaxuan Wang Wenping Zhu Guizhi(Second Crust Monitoring Center of China Earthquake Administration, Xian 710054, China)
We have inverted Haiyuan faults slipping rates and locking depths by use of Fourier solution of 3-D body force model based on Crustal Movement Observation Network of China and other of GPS profiles data. Genetic algorithm has been used to simulate the GPS velocity field iteratively. The final RMS of fitting residual is 1.1 mm/a. The result reveals that the left lateral slip rate of Maomao Shan fault is 3.5 mm/a and its locking depth is 22 km. For Laohushan fault the slip rate is 6.5 mm/a and locking depth is 10.3 km. The slip rates in western, middle and eastern segment of the Haiyuan fault are 4.0 mm/a, 5.6 mm/a and 5.5 mm/a, respectively, and the locking depths in corresponding segments are 8.4 km, 3.6 km and 4.3 km, respectively. The slip rate of Maomao Shan fault is low, while its locking depth is large, being favorite for strain energy accumulation on this fault.