Abstract
Karst aquifers represent essential water resources in many parts of the world, such as the Mediterranean basin. However, due to the complex karstification processes, these aquifers are heterogeneous at many scales and vulnerable. The dolomitic site of the "GEK" observatory, on the Durzon basin in the Larzac, makes it possible to study the potential of gravimetry and ambient seismic noise, for example for hydrological modelling in karst environments. In the observatory, this superconducting gravimeter dedicated to hydrology has been measuring gravity variations continuously and with very high accuracy since 2011.This Larzac observation site, managed by the Observatoire des sciences de l'Univers Oreme, is part of Résif, a national research infrastructure dedicated to the observation and understanding of the structure and dynamics of the Internal Earth. Résif is based on high-tech observation networks, composed of seismological, geodetic and gravimetric instruments deployed in a dense manner throughout France. These data make it possible to study with high spatial and temporal resolution the deformation of the ground, surface and deep structures, seismicity on a local and global scale and natural hazards, and more particularly seismic hazards, on French territory. Résif is integrated into European (EPOS - European Plate Observing System) and global systems of instruments for imaging the Earth's interior as a whole and studying many natural phenomena.