Possible Continuous Vertical Water Leakage of Deep Aquifer: Records from a Deep Well in Tianjin Province, North China

Figure 3

The phase responses over time (from January 1st, 1981, to May 9th, 2020) for well Gaocun at the M₂ wave (red dots) and O₁ wave (black dots) frequencies. The horizontal dashed line represents the 0° phase shifts, from which we can see the obviously separated M₂ and O₁ phase shifts. The vertical dashed lines represent the start time of the 2008 Wenchuan and the 2011 Tohoku huge earthquakes, which had not caused obvious influence on the phase shifts or the amplitude ratios. We calculated the errors based on the data from Jan. 1st, 1981, to Dec. 31st, 1990 (which is relatively stable and continuous), and obtained the error of the phase shifts of the M₂ wave with 4.08°, while O₁ wave with 4.32°, and obtained the error of the amplitude ratios of the M₂ wave with 65400.07 (m/strain), while O₁ wave with 75700.15 (m/strain).