1. The Second Monitoring and Application Center, China Earthquake Administration , Xi’an 710054 , China
2. Institute of Disaster Prevention , Yanjiao 065201 , China
3. School of Earth Sciences and Resources, Chang’an University , Xi’an 710064 , China
4. Institute of Earthquake Forecasting, China Earthquake Administration , Beijing 100036 , China
5. School of Urban Construction, Xi’an Siyuan University , Xi’an 710038 , China