The FremTeil project comes to an end: review meeting in Viviers with local residents

On September 26 and 27, 2024, the FremTeil project leaders organized a project review meeting in Viviers, to mark the end of the project. It brought together around twenty participants from the various laboratories at the Hostellerie Charles de Foucault in Viviers. The last half-day was devoted to didactic presentations designed to present the results of the research to local residents (in particular, to the local residents in whose homes the research was carried out and to the “Collectif pour les sinistrés du séisme du 11/11/2019”), as well as to representatives of the town halls of the villages located in the epicentral zone (Le Teil, Saint-Thomé) and to a few journalists. A first meeting, with over 35 participants, was organized in January 2023.

In the wake of the Le Teil earthquake (November 11, 2019, Mw 4.9), a number of scientific studies have been undertaken to clarify the characteristics and origin of this emblematic earthquake, which occurred on an ancient fault zone (the Cevennes fault system) located in an intraplate domain characterized by a very low rate of deformation, and the implications in terms of hazard in a region (the Rhône valley) where vulnerability is high.

Much of this work was carried out 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 (CFS)?” led by Jean-François Ritz (Montpellier) and supported by CNRS Terre & Univers from 2021 to 2023. Several academic laboratories were involved (including Géosciences Montpellier, ISTerre in Grenoble, Géoazur in Sophia-Antipolis and the Centre de recherche et d’enseignement des géosciences de l’environnement – Cegege, in Aix-en-Provence) as well as several institutes (IRSN, EDF, CEA, Cerema).

The FremTeil project set out to answer a number of questions: Had the Rouvière fault, responsible for the Le Teil earthquake, already ruptured in the past? Could other CFS faults, notably at the northeastern termination of the bundle, also produce this type of event? Could the triggering of the Le Teil earthquake be linked to human activity in the vicinity of the fault (rock extraction at the Lafarge quarry at the top of the fault)? What control do seismic rupture and site effects have over damage distribution and spatial variation in seismic movement?

Research is continuing, and the FremTeil “community” plans to continue collaborating to answer the questions that remain (seismology, strong movements, paleoseismology: not all CFS faults have been resolved). The first objective is to find new funding (e.g. an ANR project within the PEPR Irima framework, ….).

To know more

• Read the full minutes of the review meeting (french)
• First meeting
• List of participants at the September review meeting: Géosciences Montpellier : J-F Ritz, C. Thomasset, N. Cathelin; Isterre, Grenoble :C. Cornou, M. Causse; Géoazur : J-P. Ampuero, C. Larroque, M. Maxime Godano ; Géoressources Nancy : A. Gébelin ; IRSN : S.Baize, H. Jomard, C. Gélis, S. Hok, A. Laurendeau, H.Su ; EDF :K. Manchuel ; CEREMA : D. Mercera ; GIPSA-Lab: D.Georges, G. Besançon