Abstract
The particularity of the Larzac Observatory, created in 2011, is the instrumental and thematic association between geophysical methods and the environmental processes of this karstic system. The site is equipped with all the instruments necessary for hydro-meteorological monitoring (flow tower, weather stations, several wells allowing conductivity and flow measurements of underground flows). A fleet of surface and underground rain gauges completes the instrumentation. The photo shows the GNSS reference station HOLA that has been measuring deformations since 2013, in addition to existing long baseline inclinometry measurements. This station is part of the permanent GNSS network of the French seismological and geodetic network 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. The data collected 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 events, on French territory. Résif is part of the European (Epos - European Plate Observing System) and global systems of instruments used to image the Earth's interior as a whole and to study many natural phenomena.