STUDY ON THE CHARACTERISTICS OF GEOTHERMAL PRECURSORY ANOMALY BEFORE SIGNAL EARTHQUAKE IN NORTH CHINA AREA AND ITS SIGNIFICANCE IN PREDICTION

Signal earthquake is a kind of generalized foreshock.Geothermal precursory anomaly before signal earthquake is similar to the anomalies before main earthquake.Signal earthquake and the major earthquake seem to be controlled by the same tectonic system.It is significant to earthquake prediction to study the geothermal precursory anomaly before signal and major earthquake as well as their relation with focal mechanism.