Abstract: | Using the double-difference earthquake location algorithm,the deterministic method (PTD method) and the CAP seismic moment tensor inversion method,the paper selects the primary waveform data of 78 earthquakes recorded by the "China Earthquake Science Array Probe Project in the Northern Part of North South Seismic Belt ",the "China Earthquake Scientific Exploration Array Data Center"of Institute of Geophysics,China Earthquake Administration,and the Inner Mongolia Digital Seismic Network to calculate the focal depths of the mainshock and the seismic sequence of the M_S5.8 Alxa Left Banner earthquake in Inner Mongolia. The results show that the focal depth of the main shock is 20. 6 km,determined by the double-difference earthquake location method,18. 1 km by the PTD method,and 19. 2 km by the CAP method. The focal depth of the earthquake sequence calculated by the double-difference location method is larger. The deterministic method (PTD method) and double-difference location method are the methods that fit the tectonic characteristics of the seismic source area,and the CAP method is suitable for larger earthquakes. |