Abstract：By combining the use of high-pass filter and overrun rate analysis, high-frequency signals such as fluctuations, steps and jumps can be maximally extracted based on borehole tiltmeter observations. We can quantitatively characterize these signals and test the relationships of the signals and earthquakes. To confirm the reliability of the signals ,we must exclude the factors of pressure, water and equipment. The results show that the number and intensity of high-frequency signals significantly appears with the increasing phenomenon. The abnormal duration is mostly within three months, and belongs to short-term abnormal duration. Earthquakes occurred after the anomaly ended or three months after the end of abnormal duration.
GAO Lijuan,ANWAR Shamsiya,XING Ximin et al. Extracting Precursory Anomaly of the Borehole Tiltmeter by Means of Overrun Rate Analysis[J]. jgg, 2015, 35(4): 707-710.
