Comparison analysis on macro-anomalies before MS7.3 Yutian earthquakes in Xinjiang

There were two MS7.3 earthquakes occurred in Yutian, Xinjiang,Chinaon 21 March, 2008 and 12 February, 2014, respectively. Seismic geologi-cal surveys were carried out after both earthquakes. The surveying results show that the seismic macro-anomalies are quite different in behavior from each other, although the epicenters of the two earthquakes are only 110 km in distance. The present paper analyzed the possible reasons for macro-anomalies of the two Yutian earthquakes in behavior from the aspect of seismogenic faults, focal depth, focal mechanism and the spatio-temporal distribution of the earthquakes. The seismic characteristics in spatial distribution, physical behavior and temporal regularity in Xinjiang region are concluded. In addition, some instructive suggestions were mentioned out for macroscopic observation of earthquake inChina, combined with the progress of biological precursors of earthquakes attained inKazakhstan.