THE CHARACTER OF GROUND TILT ANOMALIES IN HUAILAI SEISMOSTATION BEFORE ZHANGBEI M6.2 EARTHQUAKE

the calibration of the SQ-70 Horizontal Pendulum Tiltmeter had dropped before Zhangbei M6.2 earthquake in Jan. 10, 1998, and it recovered after the event.Based on the analysis to the confidence of the data the character of anomalies is discussed.The main character of ground tilt anomalies is the offset of the curve recorded with light, and the frequency of offset has closed relation with seismogenic faulting.In the paper, the character of ground tilt anomalies in Huailai Seismostation before Zhangbei earthquake is discussed, in order to find an effective way of earthquake prediction with ground tilt data.