Taking these two earthquakes as the samples, the precursory differences between grouped strong earthquakes and the single strong earthquake are studied.

Based on the synthetic math expression of earthquake precursory anomaly information variable in this paper,we acquired the S-values according to the information with precursory anomaly provided by 11 seismic stations and non-precursory anomaly by 7 seismic stations before Xiuyan 5.

Based on the mechanism to induce groundwater anomaly,the interferences of precursory anomaly and its recognition are discussed,and the view of "rain and groundwater interference"is questioned.

Before the two events,a lot of precursory anomalies of subsurface fluid appeared in north Tianshan mountations area,but there is clearly difference in the anomalies before the two events.

Discussion on precursory abnormity of water chymistry mechanism in Wutazui spring;

There appeared orderly precursory abnormity of underground fluid in the northern Tienshan mountain before the earthquake,and most of them is mid-short term abnormity,concentrating on around Urumqi,which is 265 km or so from the epicenter.

The Research of Precursor Anomaly Characteristic of Ground Resistivity Anisotropy and Its Physical Mechanism in Earthquake;

Based on the method of anomaly recognition and mark system for the precursor subject, the characteristics of precursor anomaly of the ground fluid have been identified and studied during the Heze M59 earthquake in 1983 and the features of stages, layer and synchronism of precursor anomaly of ground fluid were analyzed.

Therefore,we consider that using wavelet transform method to extract seismic precursor anomaly is efficient.