The journal Comptes Rendus Géoscience has just published an article presenting the exceptional mobilization of the Résif community following the earthquake of November 11, 2019 on the town of Le Teil and which continues to this day.
On November 11, 2019 at 11:53 am the RESIF seismological stations recorded an earthquake of a magnitude greater than 5 near Montélimar. An analyst of the EOST in Strasbourg localizes the earthquake manually less than an hour later. He confirms a magnitude of 5.2 Mlv. The characteristics of the earthquake immediately appear remarkable: high magnitude and very shallow depth (2 to 3 km). This information is confirmed at the same time by the relocation work carried out at ISTerre (Grenoble) and Geoazur (Nice), where the mechanism at the focus is validated from RESIF seismological data, confirming the probable NE-SW direction of the fault.
On the same day, the national post-seismic cell was activated and, from that moment on, many instruments and scientific teams were mobilized to follow the evolution of the crisis and determine its characteristics with the highest possible accuracy (magnitude, location, depth, type of associated fault movement, ground movements…). Another surprising characteristic of this earthquake is quickly observed: it is followed by very few aftershocks. Apart from an aftershock of magnitude 1.5 three minutes after the main shock, the first aftershock (2.2 MLv) felt took place on November 13.
In the 7 days following the main shock, 47 seismological stations will be deployed in the epicentral zone to improve the localization of the aftershocks of the Teil, to follow the temporal and spatial evolution of the microseisms close to the fault plane and the temporal evolution of the seismic response of 3 damaged historic buildings, and to study the presumed effects of the site and their influence in the distribution of seismic damage.
This seismological data set, supplemented by data from different institutions, was integrated into a homogeneous archive and distributed by the Resif data center. This dataset, as well as observations of surface evidence of rupture, geological, geodetic and satellite data, are currently being studied by scientists trying to elucidate the causes and mechanism of rupture of this earthquake. These data will also contribute to the seismic hazard assessment for earthquakes along the major regional fault system of the Cévennes
 Northeast – Southwest
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On November 11, 2019 at 10:52 a.m. an earthquake of magnitude 5.2 MLv occurs near Montélimar. Within the framework of this theme “Active Faults” of the axis “Seismotectonics and Seismic Hazard of Metropolitan France” of the transverse action reactive seismicity, a team composed of eight scientists from four structures (Geosciences Montpellier, IRSN, Geoazur, ISTerre) arrives in the area on November 13. They focus their exploration on the trace identified the day before by radar interferometry. Here we see the scanner and the break in the background © Jean-François Ritz, Geosciences Montpellier. To know more about it.
A member of the Macro-seismic intervention group in the village of Le Teil during the mission related to the 5.2 Mlv earthquake near Montélimar on November 11, 2019 © Marc Schaming, Ecole et observatoire des sciences de la Terre. To know more about it.