The effects of the atmospheric pressure changes on seismic signals or how to improve the quality of a station

• Published in: Bulletin of the Seismological Society of America
• Main Authors: Beauduin, R., Lognonné, Philippe, Montagner, J., Cacho, S., Karczewski, J., Morand, M.
• Other Authors: Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPG Paris)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1996
• Subjects: [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; Macquarie Island
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03940053; https://doi.org/10.1785/BSSA0860061760

Seismic investigations are mainly limited by seismic noise. Two microbarometers have been installed in the seismic vault of two different GEOSCOPE stations, one at SSB and the other at TAM. All vertical components and most of the horizontal components show a significant correlation with pressure. In order to correct the seismic signals from the atmospheric pressure noise, a transfer function between the pressure data and the seismic data is inverted. Results show that, after correction, the noise levels reached on the horizontal components are similar between the two stations, and the vertical components display noise levels below the low-noise model as defined by Peterson (1993). This technique reduces part of the noise and allows detection of small earthquakes and a better extraction of normal modes. The analysis of the lowest normal modes of the Earth excited by the MS = 8.2 Macquarie Island earthquake is given to illustrate the perspectives of the method.