Detection and discrimination of low magnitude seismic events : Application to the Armorican Massif

Céline Hourcade (1) , Mickaël Bonnin (1, 2) , Éric Beucler (1, 2)

1 LPG - Laboratoire de Planétologie et Géodynamique [UMR 6112]
2 OSUNA - Observatoire des Sciences de l'Univers Nantes Atlantiques

The instrumental seismicity of the Armoricain Massif is often described as diffuse with low-moderate magnitude earthquakes. To study the seismicity of a stable continental region, the detection of seismic events is an essential step. The unprecedent amount of stations in the region, in the last 3 years, opens the possibility to detect low magnitude seismic events and to better characterize the seismicity of the region. The understanding of the low magnitude seismicity can be greatly influenced by the method used to detect natural events.The implementation of tools allowing a more accurate detection of earthquakes is thus essential. To achieve this objective, we have developed a detection method using a template matching approach for event detection and artificial intelligence tools to classify the detected signals and identify the arrival times of seismic waves. This method allows to extract, from the raw continuous seismic signal, a catalog of natural and anthropogenic seismic events including low amplitude earthquakes never detected before. Between January 1st and May 1st, 2021, we detected about twice as many events compared to the national institutions.

Mots clés: RESIF; Seismology; France; Epos-France

Mots clés: Epos-France; RESIF; Sismologie; France

Domaines: Géophysique [physics.geo-ph]

Céline Hourcade, Mickaël Bonnin, Éric Beucler. Detection and discrimination of low magnitude seismic events : Application to the Armorican Massif. 5èmes Rencontres Scientifiques et Techniques Résif, Nov 2021, Obernai (67210), France. ⟨hal-03442165⟩