ARCHEOSISMOTEIL

The Archeosismoteil project is at the intersection of seismology and archaeology: archaeoseismology. The project is addressing one of the main themes of the Academy: to better “identify and evaluate natural hazards and their impact on the environment, cities and societies” by making cities and human settlements inclusive, safe, resilient and sustainable.

The project is part of a larger research initiative focusing on geology and seismology in the Cevennes region, the project: Faults, Ruptures and Earthquakes and strong Motion in the region of Le Teil, a village in Ardèche, France, located near the La Rouvière fault. This INSU-CNRS project, which started in 2021 and has been running for three years, aims to study the rheology and seismic hazard of the La Rouvière fault. The sudden activity of this fault is responsible for the magnitude 4.9 earthquake that struck this region on November 11, 2019. The project covers several scientific fields: geology, geomorphology, paleoseismology and archaeoseismology. Financed by the Academy, its aim is to make an inventory of historical earthquakes and monitor the seismic resilience of medieval buildings in the region of Le Teil. The study has been planned in three phases:

• An inventory of historical earthquakes in the region and the buildings still standing as witnesses to these events.
• An on-site study around the buildings to characterize the dynamic response of the structures.

Modeling of ground motions and their consequences on old buildings.
Among the historical buildings identified, five were studied: the chapel of St Jean Baptiste de Rac, the chapel of St Blaise de Montboucher sur Jabron, the old village of Allan, the Château de St Thomé and the château de Rochemaure. The study of these historical structures provides details of their seismic behavior: amplifications, vibration frequencies, cracking zones, etc. The information gathered with the help of an M2 intern, once modeled, will be synthesized in a database and used for the preservation of historical monuments. The development of a database of the vibration modes and frequencies of monuments in the region will make it possible to anticipate their reactions and their seismic vulnerability. The Fremteil project is coming to an end and the consortium of laboratories involved is preparing to report on the progress made and their recommendations before outlining the next steps of their studies.