|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Peer-reviewed Journal Articles, etc >
Estimation of azimuthal anisotropy in the NW Pacific from seismic ambient noise in seafloor records
| Title: | Estimation of azimuthal anisotropy in the NW Pacific from seismic ambient noise in seafloor records |
| Authors: | Takeo, Akiko Browse this author | | Forsyth, Donald W. Browse this author | | Weeraratne, Dayanthie S. Browse this author | | Nishida, Kiwamu Browse this author |
| Keywords: | Surface waves and free oscillations | | Seismic anisotropy | | Dynamics of lithosphere and mantle |
| Issue Date: | Oct-2014 |
| Publisher: | Oxford University Press |
| Journal Title: | Geophysical Journal International |
| Volume: | 199 |
| Issue: | 1 |
| Start Page: | 11 |
| End Page: | 22 |
| Publisher DOI: | 10.1093/gji/ggu240 |
| Abstract: | We analysed background surface waves in seismic ambient noise by cross-correlating continuous records of eight ocean bottom seismometers and nine differential pressure gauges deployed in the northwestern Pacific Ocean by the PLATE project. After estimating the clock delay and instrumental phase responses of differential pressure gauges by using cross-correlation functions, we measured average phase velocities in the area of the array for the fundamental-, first higher- and second higher-mode Rayleigh waves, and the fundamental-mode Love waves at a period range of 3-40 s by waveform fitting. We then measured phase-velocity anomalies of fundamental-mode and first higher-mode Rayleigh waves for each pair of stations at a period range of 5-25 s, and corrected the effect of variation in water-depths. The seismic anomalies imply the presence of strong azimuthal anisotropy beneath the eastern part of array. The direction of maximum velocity is approximately N35A degrees E in the fossil seafloor spreading direction perpendicular to magnetic lineations from the ancient triple junction at this location. The peak-to-peak intensity of shear-wave velocity anisotropy in the mantle is similar to 7 per cent. |
| Rights: | This article has been accepted for publication in "Geophysical Journal International" © The Authors 2014. Published by Oxford University Press on behalf of The Royal Astronomical Society. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/57347 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 竹尾 明子
|
