DOI: 10.1002/2014GL061249
论文题名: Seismic evidence for an 850 km thick low-velocity structure in the Earth's lowermost mantle beneath Kamchatka
作者: He Y. ; Wen L. ; Zheng T.
刊名: Geophysical Research Letters
ISSN: 0094-9669
EISSN: 1944-9400
出版年: 2014
卷: 41, 期: 20 起始页码: 7073
结束页码: 7079
语种: 英语
英文关键词: core-mantle boundary
; D″
; Kamchatka
; low-velocity structure
; mantle plume
Scopus关键词: Seismology
; Structural geology
; Thermal plumes
; Velocity
; Core-mantle boundary
; Kamchatka
; Low-velocity
; Low-velocity anomaly
; Lowermost mantle
; Mantle plume
; Velocity structure
; Waveform modeling
; Shear flow
; core-mantle boundary
; mantle plume
; numerical model
; S-wave
; seismic anisotropy
; velocity structure
; Kamchatka
; Russian Federation
英文摘要: We detect an 850 km thick low-velocity structure in the Earth's lowermost mantle beneath Kamchatka surrounded by and overlying a 210 km thick high-velocity D″ structure. The velocity structure is constrained by modeling the observed anomalously broadened waveforms for seismic shear waves sampling the lowermost mantle recorded at large distances from 90° to 100°. Waveform modeling analyses reveal that the low-velocity anomaly has a stem with a diameter of about 550-km in the lowermost 210-km of the mantle and a cap with a diameter of about 1600-km. The low-velocity structure of the cap decreases from 0% at the top to -1.5% at about 400-km above the core-mantle boundary (CMB) and to -1.2% at 210-km above the CMB. We suggest that the geometrical and velocity features of the low-velocity anomaly indicate that it may represent a localized mantle plume undetected before in the lower mantle. Key Points A localized LVZ in the lowermost mantle beneath Kamchatka is detectedSuch low-velocity anomaly is not observed in most regionsIt may represent a mantle plume undetected before in the lower mantle ©2014. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911382652&doi=10.1002%2f2014GL061249&partnerID=40&md5=56c33d0b3e0608a3eb7b1f486f9e869e
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/6933
Appears in Collections: 气候减缓与适应
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作者单位: Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
Recommended Citation:
He Y.,Wen L.,Zheng T.. Seismic evidence for an 850 km thick low-velocity structure in the Earth's lowermost mantle beneath Kamchatka[J]. Geophysical Research Letters,2014-01-01,41(20).