DELOUIS , Bertrand

A propos des vibrations du sol dues à un séisme Un séisme est dû à une rupture des roches en profondeur qui occasionne un déplacement rapide des deux compartiments d'une faille. C'est un phénomène bref (quelques secondes pour les séismes faibles à modérés à quelques minutes pour les séismes majeurs) qui génère des vibrations appelées ondes...

The FMNEAR method (for determination of Focal Mechanism using NEAR‐source records) has already proved its efficiency for continental earthquakes recorded by a large number of well‐distributed stations. Installed in January 2015, it has been running in real time in Chile, in the specific tectonic conditions of the active convergent margin of the...

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Le CEA a une mission d'alerte séisme en France métropolitaine qui consiste à prévenir rapidement les autorités françaises de l'occurrence d'un séisme.La méthode GRiD MT se base sur un unique algorithme automatique d'inversion du tenseur des moments sur grille qui permet simultanément la détection, la localisation et la caractérisation rapides...

Abstract The Loreto earthquake of 26 May 2019 occurred below the extreme northeast part of Peru at a depth of 140 km within the subducting Nazca plate at a distance of 700 km from the trench Peru–Chile. The orientation of the seismic source was obtained from waveform inversion in the near field using velocity and strong-motion data. The rupture...

The earthquake of magnitude ML(RENASS)=4.8 and ML(CEA-LDG) 5.2 occurred on 21 June 2019 at 6 h 50 min UT 8. h 50 min in local time). The moment magnitude (Mw) is calculated between 3.9 and 4.0. The mechanism at the focus is essentially stalling. Waveform inversion indicates a preferential depth between 5 and 7 km. The epicentre is located 6 km...

Abstract As tsunamis propagate across open oceans, they remain largely unseen due to the lack of adequate sensors. To address this fundamental limitation of existing tsunami warnings, we investigate Global Navigation Satellite Systems (GNSS) data to monitor the ionosphere Total Electron Content (TEC) for Traveling Ionospheric Disturbances...

document d'information sur le risque sismique sur la Côte d'Azur et les Alpes du Sud pour le grand public

Fin 2019, un tremblement de terre d'une ampleur exceptionnelle pour la région se déclenche en Ardèche. S'il n'y a pas de victimes, les destructions du village du Teil sont importantes. Les particularités de l'événement et la présence d'une grande carrière de ciment, à l'aplomb de la faille qui a rompu, interrogent les scientifiques. Serait-il...

document d'information sur le risque sismique sur la Côte d'Azur et les Alpes du Sud pour le grand public

International audience

The February 10, 2024 (Universal Time) earthquake is located in Haute-Saône, east of Vesoul. The local magnitude of the main earthquake, calculated by BCSF-Rénass and CEA-DASE, is 3.6 MLV and 3.8 ML respectively. The moment magnitude (Mw) calculated by Géoazur is 2.9. The depth of the focus varies between 10 and 19 km, depending on the...

The May 29, 2023 earthquake is located in Switzerland, close to the border with France (1 km), west-southwest of Porrentruy. It follows a series of earthquakes of equivalent magnitude already recorded in this area since December 2021. The local magnitude of the main earthquake calculated by the various national organizations (BCSF-Rénass,...

International audience

The SW Alps are an active orogen undergoing intra-mountainous extension and peripheral compression. We discuss the significance of syn-orogenic extension based on a comparison of paleo-stress derived from faultslip data inversion reflecting the long-term (b12 Ma) evolution of SW Alps and the present-day stress state obtained by the inversion of...

International audience

International audience

The Rhône River Valley in France, a densely populated area with many industrial facilities including several nuclear power plants, was shaken on November 11th 2019, by the Mw 4.9 Le Teil earthquake. Here, we report field, seismological and interferometric syntheticaperture radar observations indicating that the earthquake occurred at a very...