DOI: 10.1016/j.epsl.2020.116086
论文题名: Shear wave velocity and radial anisotropy structures beneath the central Pacific from surface wave analysis of OBS records
作者: Yang X. ; Luo Y. ; Xu H. ; Zhao K.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 534 语种: 英语
中文关键词: central Pacific plate
; oceanic lithosphere and asthenosphere
; phase velocity
; seismic anisotropy
; surface wave
英文关键词: Acoustic wave velocity
; Analytical geochemistry
; Anisotropy
; Mathematical transformations
; Phase velocity
; Plates (structural components)
; Rayleigh waves
; Seismology
; Shear strain
; Shear waves
; Structural geology
; Surface waves
; Water waves
; Broadband ocean-bottom seismometers
; Differential pressures
; Numerical simulation studies
; Oceanic lithosphere
; Pacific plates
; Seismic anisotropy
; Surface-wave analysis
; Surface-wave tomography
; Shear flow
; asthenosphere
; Love wave
; ocean bottom seismometer
; oceanic lithosphere
; Pacific plate
; phase velocity
; Rayleigh wave
; S-wave
; seismic anisotropy
; seismic velocity
; Pacific Ocean
; Pacific Ocean (Central)
英文摘要: The central Pacific plate is an ideal area to study the dynamics of the lithosphere-asthenosphere system, as this region is far away from other dynamics systems, such as subduction zones and volcanic hotspots of mantle plumes, and has experienced simple oceanic evolution. In this study, we collect three-component continuous seismic data and differential pressure gauge data recorded by 15 broadband ocean bottom seismometers (OBSs) from the NoMelt experiment. We process continuous seismic noise data to obtain phase velocities of the fundamental (6-30 s) and first high (5-11 s) mode Rayleigh waves and fundamental mode Love waves (5-12 s). We apply a two-plane-wave method to teleseismic Rayleigh waves to obtain the fundamental mode phase velocities at 20-150 s periods, and apply high-resolution linear Radon transform to teleseismic Love waves to obtain phase velocities for the fundamental mode Love waves at 28-48 s periods. Then, we jointly invert the average phase velocities of Rayleigh and Love waves to construct 1-D isotropic shear wave velocity and radial anisotropy from the seafloor to 150 km depth beneath the NoMelt region. Our 1-D model shows a low velocity zone (LVZ) beneath a high velocity lid. By comparing our results with the predictions of partial melt models, we suggest the LVZ is attributed to the presence of a small amount of melt in the asthenosphere. Strong radial anisotropy (5-6%) is observed in the crust. But the mantle lithosphere is characterized by weak radial anisotropy (< 1%), consistent with the corner mantle flow history at the mid-ocean ridge during the formation of new oceanic plates. Strong radial anisotropy (4-5%) is observed in the asthenosphere, which is consistent with the global surface wave tomography results and numerical simulation studies, reflecting the strong shear strain of asthenosphere related to the motion of oceanic plate over the underlying asthenosphere. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165364
Appears in Collections: 气候变化与战略
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作者单位: Hubei Subsurface Multi-Scale Imaging Lab (SMIL), Institute of Geophysics and Geomatics, China University of Geosciences (Wuhan), Wuhan, Hubei 430074, China; State Key Laboratory of Geological Processes and Mineral Resources, Institute of Geophysics and Geomatics, China University of Geosciences (Wuhan), Wuhan, Hubei 430074, China
Recommended Citation:
Yang X.,Luo Y.,Xu H.,et al. Shear wave velocity and radial anisotropy structures beneath the central Pacific from surface wave analysis of OBS records[J]. Earth and Planetary Science Letters,2020-01-01,534