Evidence for changes in the dynamics of Earth crust tilts caused by the large dam construction and reservoir filling at the Enguri dam international test area (Georgia)

Abstract

This study is focused on the analysis of the dynamics of Earth crust tilting at the Enguri Dam International Test Area (EDITA). We aimed to perform a qualitative and quantitative evaluation of the dynamical properties of Earth tilt time series in the context of the development of a real-time telemetric monitoring system at the Enguri test area. The set of Earth tilt hourly time-series data, recorded during the construction of the Enguri power station and subsequent fill of reservoir (1971–1983), has been analyzed. Modern methods of linear and nonlinear time-series analysis have been used. It has been observed that Earth tilt sequences clearly reveal properties of low-dimensional dynamics. Quantitative changes in the dynamics of tilt generation connected with different stages of anthropogenic influence, such as the construction of the Enguri high dam and reservoir fill, have also been detected. It was shown that these changes are transient, since the character of Earth tilt dynamics has been restored at the end of observation.