ANALYSIS ON THE SHORT-TERM ANOMALIES OF EARTHQUAKE IN NORTH CHINA AND THE EXTRACTION OF THEIR PRECURSORY INFORMATION

Based on some previous study, a large number of precursory data observed in North China (34°~42°N, 108°~124°E) since 1980 were systematically analyzed. According to the ability reflecting earthquakes, 114 items of the data are confirmed as main precursory data in North China. On the basis of above, the main characteristics of short-term precursory anomalies in North China as well as their recognition are studied, and the method to extract precursory information from short-term anomaly in North China area is presented. The application shows that this method not only can unify the dimensions of various short-term precursory anomalies, but also can reflect their short-term variation objectively.