Detection of microseismic compressional (P) body waves aided by numerical modeling of oceanic noise sources - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Journal of Geophysical Research : Solid Earth Année : 2013

Detection of microseismic compressional (P) body waves aided by numerical modeling of oceanic noise sources

Résumé

Among the different types of waves embedded in seismic noise, body waves present appealing properties but are still challenging to extract. Here we first validate recent improvements in numerical modeling of microseismic compressional (P) body waves and then show how this tool allows fast detection and location of their sources. We compute sources at 0.2 Hz within typical P teleseismic distances (30-90°) from the Southern California Seismic Network and analyze the most significant discrete sources. The locations and relative strengths of the computed sources are validated by the good agreement with beam-forming analysis. These 54 noise sources exhibit a highly heterogeneous distribution, and cluster along the usual storm tracks in the Pacific and Atlantic oceans. They are mostly induced in the open ocean, at or near water depths of 2800 and 5600 km, most likely within storms or where ocean waves propagating as swell meet another swell or wind sea. We then emphasize two particularly strong storms to describe how they generate noise sources in their wake. We also use these two specific noise bursts to illustrate the differences between microseismic body and surface waves in terms of source distribution and resulting recordable ground motion. The different patterns between body and surface waves result from distinctive amplification of ocean wave-induced pressure perturbation and different seismic attenuation. Our study demonstrates the potential of numerical modeling to provide fast and accurate constraints on where and when to expect microseismic body waves, with implications for seismic imaging and climate studies.
Fichier principal
Vignette du fichier
JGR Solid Earth - 2013 - Obrebski - Detection of microseismic compressional P body waves aided by numerical modeling of.pdf (4.78 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

insu-03581775 , version 1 (21-02-2022)

Licence

Copyright (Tous droits réservés)

Identifiants

Citer

Mathias Obrebski, Fabrice Ardhuin, Eleonore Stutzmann, Martin Schimmel. Detection of microseismic compressional (P) body waves aided by numerical modeling of oceanic noise sources. Journal of Geophysical Research : Solid Earth, 2013, 118, pp.4312-4324. ⟨10.1002/jgrb.50233⟩. ⟨insu-03581775⟩
15 Consultations
19 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More