Optical long range instruments for high resolution monitoring of geohazard in harsh environment

Pascal Bernard (1) , Guy Plantier (2, 3) , Philippe Ménard (2) , Mathieu Feuilloy (2, 3) , Romain Feron (2, 3) , Damien Guitton (2) , Guillaume Savaton (2) , Sébastien Deroussi (1) , Yann Hello (4) , Alexandre Nercessian (1) , Roberto Moretti (1) , Frédérick Boudin (5) , Arnaud Lemarchand (1) , Jean-Philippe Métaxian (1) , Roberto Longo (2, 3) , Maurizio Ripepe (6) , Thierry Pommeau (2) , Eléonore Stutzmann (1) , Alister Trabattoni (2) , Félix Léger (1)

1 IPGP (UMR_7154) - Institut de Physique du Globe de Paris
2 GSII - ESEO-GSII
3 LAUM - Laboratoire d'Acoustique de l'Université du Mans
4 GEOAZUR 7329 - Géoazur
5 ENS-PSL - École normale supérieure - Paris
6 UniFI - Università degli Studi di Firenze = University of Florence = Université de Florence

In many areas with high telluric hazard, our understanding of the seismogenic and mechanical processes is limited by the difficulty or impossibility to deploy arrays of high performance seismometers or of other geophsyical sensors, due to high cost and/or difficulty of the installation and maintenance. This led us to develope several optical instruments: the idea was to separate, by a long optical fiber, the robust mechanical part of the sensor from the opto-electronic part, which interrogates the sensor and measures its internal deformation with Fabry-Perot (FP) interferometry. Our IPGP-ESEO team has thus constructed innovative optical seismometers and strainmeters, complemented by borehole and long base optical tiltmeters from Geoscience Montpellier and ENS. Here we present the ESEO-IPGP instruments, and their successful installation in the field: one seismometer at the top of La Soufrière volcano (1.5 km long fiber), 10/2019 (ANR HIPERSIS ); one ocean-bottom seismometer offshore Les Saintes, 06/2021 (FIBROSAINTES, Interreg Caraïbe PREST) (5 km long fiber buried by a plow GEOAZUR); and one strainmeter on the Stromboli volcano (09/2021).

Mots clés: RESIF; Seismology; Epos-France

Mots clés: Epos-France; RESIF; Sismologie

Domaines: Géophysique [physics.geo-ph]

Pascal Bernard, Guy Plantier, Philippe Ménard, Mathieu Feuilloy, Romain Feron, et al.. Optical long range instruments for high resolution monitoring of geohazard in harsh environment. 5èmes Rencontres Scientifiques et Techniques Résif, Nov 2021, Obernai (67210), France. ⟨hal-03482639⟩