Sensitivity of seismic-noise based methods to controlled water content changes : insight from laboratory measurements
Abstract
In recent years, seismic-noise based methods have shown great potential for the monitoring of various processes occurring in the Earth's crust. Among them, the fine detection of hydrological variations at different scales is a major issue in the context of water resources management (Gaubert-Bastide et al. 2022). In order to better understand the sensitivity of continuous seismic wavefields to water content variations affecting both saturated and unsaturated zones, we have set up a dynamic and meter-scale laboratory experiment. This sandbox experiment reproduces field surveys based on the recording and processing of seismic background noise (hundred to kiloHertz range) in the context of hydrological variations. These multiple measurements, which benefit from independent measurements of pressure and water saturation at different depths, allow us to refine the sensitivity of the seismic wavefield to variations in water content and hysteretic behavior related to different phases of imbibition/drainage.