WATER LEVEL MONITORING IN A WELL: IMPLICATIONS FOR ELASTIC CONSTANTS OF THE AQUIFER

Abstract

Water-level fluctuations in wells open to artesian aquifers record pressure head disturbances caused by dilatation of the aquifer and reflect tide, barometric, and tectonic effects. Monitoring of atmospheric pressure and water level in a deep well 300 km far from the Russian Pacific coast (Bychikha site, near Khabarovsk) was used to study the response of the well-aquifer system to periodic loading. The monitoring data were processed to obtain the elastic constants and porosity of the aquifer using analysis of several static models. The experiment confirmed the possibility to monitor these parameters to an accuracy of 1 % and to separate the tectonic component of the pressure head. Anomalous water level changes were analyzed in relation to earthquake nucleation.