Abstract
This picture shows the survey work of a trench dug across the Rouvière fault (Cevennes fault cluster), along the section that broke during the Teil earthquake of 11-11-2019. This earthquake, unprecedented in several respects, raises many questions, particularly in terms of seismic hazard. For example: Had the Rouvière fault already broken in the past? Could other faults, especially in this northeastern region of the Cevennes network, also produce this type of event? To answer these questions, research is being conducted as part of the FREMTEIL project "Faults, ruptures and strong movements in the Teil region: what consequences for the seismic hazard on the north-eastern Cevennes cluster?". It started at the beginning of 2021 for three years within the framework of the CNRS-INSU Tellus program. It finances paleoseismological, seismological and rheological research (study of the mechanical properties of the rupture zone) and takes place within the framework of the Active Faults France (FACT) axis of the Résif Seismicity Transverse Action.Résif is 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.