用超限率分析法提取钻孔倾斜地震前兆异常信号

选取钻孔倾斜观测资料,结合运用高通滤波与超限率方法,最大限度地提取波动、阶跃、突跳等高频信号,并定量描述这些信号的特征,检验此类信号与地震的关系。为确认信号的可靠性,排除气压、水位及仪器等因素影响。结果显示,中强地震前高频信号的数量和强度出现显著增大现象,多集中在3个月内,属短期异常,发震时间多为异常过程中或异常结束后3个月内。

Extracting Precursory Anomaly of the Borehole Tiltmeter by Means of Overrun Rate Analysis

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.