Skip to Main content Skip to Navigation
Journal articles

Sources of secondary microseisms in the Indian Ocean

Abstract : Ocean waves activity is a major source of microvibrations that travel through the solid Earth, known as microseismic noise and recorded worldwide by broadband seismometers. Analysis of microseismic noise in continuous seismic records can be used to investigate noise sources in the oceans such as storms, and their variations in space and time, making possible the regional and global-scale monitoring of the wave climate. In order to complete the knowledge of the Atlantic and Pacific oceans microseismic noise sources, we analyse 1 yr of continuous data recorded by permanent seismic stations located in the Indian Ocean basin. We primarily focus on secondary microseisms (SM) that are dominated by Rayleigh waves between 6 and 11 s of period. Continuous polarization analyses in this frequency band at 15 individual seismic stations allow us to quantify the number of polarized signal corresponding to Rayleigh waves, and to retrieve their backazimuths (BAZ) in the time–frequency domain. We observe clear seasonal variations in the number of polarized signals and in their frequencies, but not in their BAZ that consistently point towards the Southern part of the basin throughout the year. This property is very peculiar to the Indian Ocean that is closed on its Northern side, and therefore not affected by large ocean storms during Northern Hemisphere winters. We show that the noise amplitude seasonal variations and the backazimuth directions are consistent with the source areas computed from ocean wave models.
Document type :
Journal articles
Complete list of metadatas

Cited literature [48 references]  Display  Hide  Download

https://hal.univ-reunion.fr/hal-01236096
Contributor : Guilhem Barruol <>
Submitted on : Tuesday, December 1, 2015 - 11:38:45 AM
Last modification on : Friday, March 27, 2020 - 2:14:11 AM
Long-term archiving on: : Wednesday, March 2, 2016 - 12:12:15 PM

File

Davy_sources_SM_Indian_ocean_G...
Publisher files allowed on an open archive

Identifiers

Citation

Céline Davy, Eléonore Stutzmann, Guilhem Barruol, Fabrice R. Fontaine, Martin Schimmel. Sources of secondary microseisms in the Indian Ocean. Geophysical Journal International, Oxford University Press (OUP), 2015, 202 (2), pp.1180-1189. ⟨10.1093/gji/ggv221⟩. ⟨hal-01236096⟩

Share

Metrics

Record views

520

Files downloads

977