Rapid response to the Mw 4.9 earthquake of November 11, 2019 in Le Teil, Lower Rhône Valley, France
Authors: Cornou Cécile , Ampuero Jean-Paul , aubert Coralie , Audin Laurence , Baize Stéphane , Billant Jérémy , Brenguier Florent , Causse Mathieu , Chlieh Mohamed , Combey Andy , de Michele Marcello , Delouis Bertrand , Deschamps Anne , Ferry Matthieu , Foumelis Michael , Froment Bérénice , Gélis Céline , Grandin Raphaël , grasso jean-robert , Hannouz Estelle , Hok Sébastien , Jung Axel , Jolivet Romain , Langlais Mickaël , Langlaude Philippe , Larroque Christophe , Leloup Philippe Hervé , Manchuel Kevin , Marconato Léo , Maron Christophe , Mathot Emmanuel , Maufroy Emeline , Mercerat Diego , Métois Marianne , Neyman Emmanuelle , Pondaven Ildut , Provost Ludmila , Régnier Julie , Ritz Jean-François , Rivet Diane , Schlupp Antoine , Sladen Anthony , Voisin Christophe , Walpersdorf Andrea , Wolynieck David , Allemand Pascal , Beck Elise , Bertrand Etienne , Bertrand Véronique , Briole Pierre , Brunel Didier , Cavalié Olivier , Chèze Jérôme , Courboulex Françoise , Douste-Bacqué Isabelle , Dretzen Rémi , Giampietro Tiziano , Godano Maxime , Grandjean Philippe , Grunberg Marc , Guérin Gauthier , Guillot Stéphane , Haber Elias el , Hernandez Alain , Jomard Hervé , Lasserre Cécile , Liang Chao , Lior Itzhak , Martin Xavier , Mata Daniel , Ménager Marine , Mercier Antoine , Mordret Aurélien , Oral Elif , Paul Anne , Peix Fabrice , Péquégnat Catherine , Pernoud Michel , Satriano Claudio , Sassi Rihab , Schaming Marc , Sellier Valérie , Sira Christophe , Socquet Anne , Sue Christian , Trilla Aurélie , Vallée Martin , van den Ende Martijn , Vernant Philippe , Vial Benjamin , Weng Huihui 
Published: September 2020

On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower Rhône Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude,  and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations),  geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional Cévenne fault system in a context of present-day compressional tectonics.