UC Berkeley

Documentation and analysis of groundwater responses to induced earthquakes are important to better understand their influence on shallow groundwater systems and hydrogeological properties and processes. Here we show that induced seismicity in Oklahoma can cause changes of groundwater level over distances >150 km from the epicenter. We test existing models for the cause of the observed responses and find that the model most consistent with observations is enhanced crustal permeability produced by seismic waves, changing aquifer recharge. Simulation suggests that the sources of this recharge are close to the responding wells and have lateral dimensions of ∼100 m. Continuous monitoring of pressure and temperature in wells, installing clustered wells to monitor multiple water levels near injection sites, and isotopic and chemical analysis of groundwater near injection sites are required to better understand and quantify the recharging sources.