title: Prompt gravity signal induced by the 2011 Tohoku-Oki earthquake.
abstract: Transient gravity changes are expected to occur at all distances during an earthquake rupture, even before the arrival of seismic waves. Here we report on the search of such a prompt gravity signal in data recorded by a superconducting gravimeter and broadband seismometers during the 2011 Mw 9.0 Tohoku-Oki earthquake. During the earthquake rupture, a signal exceeding the background noise is observed with a statistical significance higher than 99% and an amplitude of a fraction of μGal, consistent in sign and order of magnitude with theoretical predictions from a first-order model. While prompt gravity signal detection with state-of-the-art gravimeters and seismometers is challenged by background seismic noise, its robust detection with gravity gradiometers under development could open new directions in earthquake seismology, and overcome fundamental limitations of current earthquake early-warning systems imposed by the propagation speed of seismic waves.
authors.affiliation: Laboratoire de Sismologie, Institut de Physique du Globe, UMR/CNRS 7154, 1 rue Jussieu, 75238 Paris, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Montagner
authors.affiliation: Laboratoire de Sismologie, Institut de Physique du Globe, UMR/CNRS 7154, 1 rue Jussieu, 75238 Paris, France.
authors.forename: Kévin
authors.initials: K
authors.lastname: Juhel
authors.affiliation: APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, 10 Rue Alice Domon et Léonie Duquet, F-75205 Paris Cedex 13, France.
authors.forename: Matteo
authors.initials: M
authors.lastname: Barsuglia
authors.affiliation: Seismological Laboratory, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, USA.
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Ampuero
authors.affiliation: APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, 10 Rue Alice Domon et Léonie Duquet, F-75205 Paris Cedex 13, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Chassande-Mottin
authors.affiliation: National Institute for Nuclear Physics, Sezione Firenze, Via G Sansone 1, Sesto Fiorentino, 50019 and Università degli Studi di Urbino "Carlo Bo", I-61029 Urbino, Italy.
authors.forename: Jan
authors.initials: J
authors.lastname: Harms
authors.affiliation: Department of Physics, 2001 Museum Road, University of Florida, Gainesville, Florida 32611-8440, USA.
authors.forename: Bernard
authors.identifier: 0000-0002-8501-8669
authors.initials: B
authors.lastname: Whiting
authors.affiliation: Laboratoire de Sismologie, Institut de Physique du Globe, UMR/CNRS 7154, 1 rue Jussieu, 75238 Paris, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Bernard
authors.affiliation: Laboratoire de Sismologie, Institut de Physique du Globe, UMR/CNRS 7154, 1 rue Jussieu, 75238 Paris, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Clévédé
authors.affiliation: Laboratoire de Sismologie, Institut de Physique du Globe, UMR/CNRS 7154, 1 rue Jussieu, 75238 Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lognonné