DOI: 10.1016/j.epsl.2018.02.032
Scopus记录号: 2-s2.0-85042920058
论文题名: P-wave attenuation in the Pacific slab beneath northeastern Japan revealed by the spectral ratio of intraslab earthquakes
作者: Shiina T. ; Nakajima J. ; Matsuzawa T.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 489 起始页码: 37
结束页码: 48
语种: 英语
英文关键词: corner frequency
; intraslab earthquakes
; P-wave attenuation
; Pacific slab
; spectral ratio
Scopus关键词: Geophysics
; Seismic waves
; Seismology
; Corner frequency
; Intermediate depths
; P waves
; Pacific slab
; Seismogenic zones
; Spectral amplitude
; Spectral ratios
; Structural effect
; Earthquakes
; amplitude
; earthquake intensity
; P-wave
; S-wave
; seismicity
; seismogram
; slab
; wave attenuation
; Japan
英文摘要: We investigate P-wave attenuation, Qp −1, in the Pacific slab beneath northeastern (NE) Japan, adopting for the first time the spectral ratio technique for intraslab earthquakes. When seismograms of two earthquakes are recorded at a station and their ray paths to the station are largely overlapped, station-dependent amplification and structural effects on the overlapped rays can be canceled out from the ratio of the spectral amplitudes of the seismograms. Therefore, adopting the spectral ratio technique for intraslab earthquakes has a great advantage for the precise evaluation of Qp −1 in the slab because the structural effects above the slab, including the high-attenuation mantle wedge, are removed. For estimating the intraslab Qp −1, we determined corner frequency of the intraslab earthquakes using the S-coda wave spectral ratio as the first step. Then, we evaluated the inter-event path attenuation, Δt⁎, from the ratio of the spectral amplitudes of P waves. The obtained result shows that P-wave attenuation in the Pacific slab marks Qp −1 of 0.0015 (Qp of ∼670) at depths of 50–250 km. This indicates that the P-wave attenuation in the Pacific slab is weaker than that in the mantle wedge. The relatively high-Qp −1 is correlated with the distributions of intraslab earthquakes, suggesting that the P-wave amplitude is more attenuated around active seismicity zones in the slab. Therefore, our observations likely indicate the presence of fractures, hydrous minerals, and dehydrated fluid around seismogenic zones in the slab at intermediate depths. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109973
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University, Sendai, Japan; Institute of Seismology and Volcanology, Graduate School of Science, Hokkaido University, Sapporo, Japan; Department of Earth and Planetary Sciences, School of Science, Tokyo Institute of Technology, Tokyo, Japan
Recommended Citation:
Shiina T.,Nakajima J.,Matsuzawa T.. P-wave attenuation in the Pacific slab beneath northeastern Japan revealed by the spectral ratio of intraslab earthquakes[J]. Earth and Planetary Science Letters,2018-01-01,489