DOI: 10.1002/2016GL069891
论文题名: The influence of shear-velocity heterogeneity on ScS2/ScS amplitude ratios and estimates of Q in the mantle
作者: Chaves C.A.M. ; Ritsema J.
刊名: Geophysical Research Letters
ISSN: 0094-8828
EISSN: 1944-8559
出版年: 2016
卷: 43, 期: 15 起始页码: 7997
结束页码: 8005
语种: 英语
英文关键词: influence of shear wave heterogeneity on ScS phases
; multiple ScS phases
; ScS amplitude ratio and delay time
; shear wave attenuation in the mantle
; tomography
Scopus关键词: Shear waves
; Tomography
; Amplitude ratios
; Influence of shear wave heterogeneity on ScS phases
; Multiple ScS phases
; Quality factor Q
; Shear wave attenuation
; Shear wave velocity
; Spectral element method
; Temperature variation
; Shear flow
; amplitude
; anomaly
; correlation
; earthquake event
; heterogeneity
; mantle process
; numerical model
; S-wave
; temperature effect
; travel time
; wave attenuation
; wave scattering
; waveform analysis
; Fiji
; Tonga
英文摘要: Regional waveforms of deep-focus Tonga-Fiji earthquakes indicate anomalous traveltime differences (ScS2-ScS) and amplitude ratios (ScS2/ScS) of the phases ScS and ScS2. The correlation between the ScS2-ScS delay time and the ScS2/ScS amplitude ratio suggests that shear wave apparent Q in the mantle below the Tonga-Fiji region is highest when shear wave velocities are lowest. This observation is unexpected if temperature variations were responsible for the seismic anomalies. Using spectral element method waveform simulations for four tomographic models, we demonstrate that focusing and scattering of shear waves by long-wavelength 3-D heterogeneity in the mantle may overwhelm the signal from intrinsic attenuation in long-period ScS2/ScS amplitude ratios. The tomographic models reproduce the trends in recorded ScS2-ScS difference times and ScS2/ScS amplitude ratios. Although they cannot be ruled out, variations in shear wave attenuation (i.e., the quality factor Q) are not necessary to explain the data. ©2016. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84981525273&doi=10.1002%2f2016GL069891&partnerID=40&md5=b4e84ebff860ca1001a2cfcc25257680
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/9791
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, United States
Recommended Citation:
Chaves C.A.M.,Ritsema J.. The influence of shear-velocity heterogeneity on ScS2/ScS amplitude ratios and estimates of Q in the mantle[J]. Geophysical Research Letters,2016-01-01,43(15).