The effect of local wind on seismic noise near 1 Hz at the MELT site and in Iceland

Almenn færsla
dc.contributorHáskóli Íslandsen_US
dc.contributorUniversity of Icelanden_US
dc.contributor.authorWilcock, William S. D.
dc.contributor.authorWebb, Spahr C.
dc.contributor.authorBjarnason, Ingi Þorleifur
dc.contributor.departmentRaunvísindastofnun (HÍ)en_US
dc.contributor.departmentScience Institute (UI)en_US
dc.contributor.schoolVerkfræði- og náttúruvísindasvið (HÍ)en_US
dc.contributor.schoolSchool of Engineering and Natural Sciences (UI)en_US
dc.date.accessioned2018-02-14T11:32:03Z
dc.date.available2018-02-14T11:32:03Z
dc.date.issued1999
dc.description.abstractThe mantle electromagnetic and tomography (MELT) experiment on the east Pacific rise near 17°S was the first large teleseismic experiment on a midocean ridge. During the six-month deployment, no compressional arrivals were well recorded above 0.5 Hz. In comparison, the ICEMELT experiment in Iceland recorded compressional arrivals at 1-2 Hz from about 2 earthquakes per month. We compare noise spectra from the two experiments and show that this difference in detection is at least in part a result of noise. Near 1 Hz, seismic noise in the oceans is produced locally by wind-generated waves. At both experiment sites, 1-Hz noise levels are well correlated with local sea-surface-wind speeds derived from satellite observations. For a given wind speed, 1-Hz noise levels are about 10-20 dB lower in Iceland. At the MELT site, cross-correlations of wind speed with the logarithm of noise in a narrow-frequency band yield correlation coefficients exceeding 0.7 at frequencies between 0.4 Hz and 2 Hz. Noise levels at 1 Hz increase with wind by 1.3-1.4 dB per m/sec for wind speeds less than 10 m/sec. For the ICEMELT experiment, high correlation coefficients extend to markedly higher frequencies for coastal stations, and there is a 10-dB drop in 1-Hz noise levels 100-km inland. Noise levels increase by about 0.8 dB per m/sec. The strong correlation between wind speed and l-Hz seismic noise provides justification for using satellite wind speed data to search for locations on the global spreading system where there is a better probability of recording high-frequency arrivals. The calmest sites are found on the northern east Pacific rise, near the equator in all oceans, and near 34 ° N and 22 ° S on the mid- Atlantic ridge.en_US
dc.description.sponsorshipThis study was supported by the National Science Foundation under grant OCE-9414299.en_US
dc.description.versionPeer Revieweden_US
dc.format.extent1543-1557en_US
dc.identifier.citationWilliam S. D. Wilcock, Spahr C. Webb, Ingi Þorleifur Bjarnason. (1999). The effect of local wind on seismic noise near 1 Hz at the MELT site and in Iceland. Bulletin of the Seismological Society of America, 89(6), 1543-1557.en_US
dc.identifier.journalBulletin of the Seismological Society of Americaen_US
dc.identifier.urihttps://hdl.handle.net/20.500.11815/572
dc.language.isoenen_US
dc.publisherThe Seismological Society of Americaen_US
dc.relation.ispartofseriesBulletin of the Seismological Society of America;89(6)
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectJarðmöttullen_US
dc.subjectJarðeðlisfræðien_US
dc.subjectSneiðmyndatökuren_US
dc.subjectJarðskjálftaren_US
dc.subjectJarðskjálftamælingaren_US
dc.titleThe effect of local wind on seismic noise near 1 Hz at the MELT site and in Icelanden_US
dc.typeinfo:eu-repo/semantics/articleen_US

Skrár

Original bundle

Niðurstöður 1 - 1 af 1
Thumbnail Image
Nafn:
wilcock_etal_seismic_noise_open_bssa1999.pdf
Stærð:
1.83 MB
Snið:
Adobe Portable Document Format
Description:
Publisher´s version (útgefin grein)
Hlaða niður

Undirflokkur

Greinar- HÍ

Öll gögn í Opnum vísindum eru vernduð af ákvæðum höfundalaga og með öllum réttindum áskildum, nema annað sé tekið fram.