THE ANALYSIS RESULTS OF WATER-WELL EARTH TIDES AND THEIR APPLICATIONS TO EARTHQUAKE PREDICTION
Liu Lanbo Zheng Xiangyuan (Center for Analysts and Prediction, State Seismological Bureau)
The time domain and frequency domain have been analysed for the two-year data of water-level and barometrical observations in the same wells of Gaocun, Tianjin; Fanxian County, Henan Province; and Wali, Beijing. The amplitude ratio and the time lag of the well earth tides versus the tidal theoretical value of dilatation of the earth, as well as the barometric efficiency B of the well-aquifer system have been given. The analysis results have demonstrated that the sensitivity of Gaocun well corresponds to 0.25 nanostrain per millimeter and the wells seem to have approached the level of the advanced Sacks-Evertson volumetric strainmeter. The aquifer bulk modulus Ba, the average porosity n and the aquifer vertical compression modulus Ev can be obtained from further analysis results.The analysis results of the three wells have also reflected the variation of the earth Love number with the tidal frequency, caused by the dynamic effect of the liquid earth core. Such analysis results published both nationally and internationally are rare.