DOI: 10.1016/j.epsl.2018.05.035
Scopus记录号: 2-s2.0-85048591335
论文题名: Shear attenuation beneath the Juan de Fuca plate: Implications for mantle flow and dehydration
作者: Ruan Y. ; Forsyth D.W. ; Bell S.W.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 496 起始页码: 189
结束页码: 197
语种: 英语
英文关键词: Cascadia Initiative
; dynamic upwelling and downwelling
; Juan de Fuca plate
; premelting effect
; Rayleigh waves
; shear attenuation
Scopus关键词: Flow patterns
; Melting
; Plates (structural components)
; Rayleigh waves
; Shear waves
; Submarine geology
; Velocity
; Cascadia
; Down-welling
; Mantle upwellings
; Melt distributions
; Ocean bottom seismometer
; Premelting effect
; Shear attenuation
; Shear wave attenuation
; Shear flow
; dehydration
; Juan de Fuca plate
; mantle
; melting
; mid-ocean ridge
; ocean bottom seismometer
; Rayleigh wave
; S-wave
; seismic attenuation
; seismic velocity
英文摘要: At mid-ocean-ridge spreading centers, the separation of lithospheric plates induces upwelling and pressure-release melting in the upper mantle. Many questions remain about the associated flow pattern, melt distribution, and the interaction of spreading centers with hotspots. Based on the propagation of Rayleigh waves across arrays of ocean-bottom seismometers, we present shear wave attenuation and velocity models in the vicinity of the Juan de Fuca plate with the best resolution to date of any spreading center. There is strong attenuation centered at depths of 70–80 km, just below the expected dry solidus. The top of the attenuating region is somewhat deeper than predicted for the thermal effects of passive mantle upwelling beneath the spreading center. The shear velocity structure shows the lowest velocities west of the spreading center, particularly near Axial Seamount and high velocities east of the axis extending to a greater depth than predicted by the passive flow model. Together, these observations support a model in which buoyant upwelling and melt extraction west of the spreading center first depletes and dehydrates the mantle above the dry solidus and then the associated downwelling carries depleted, melt-free, residual mantle downward beneath the Juan de Fuca plate. The shear velocities and attenuation can be well matched with a model in which the dominant changes in the physical properties occur just before the onset of melting. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109790
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: School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210046, China; Department of Geosciences, Princeton University, Princeton, NJ 08544, United States; Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02906, United States; Graduate School of Oceanography, University of Rhode Island, Kingston, RI 02881, United States
Recommended Citation:
Ruan Y.,Forsyth D.W.,Bell S.W.. Shear attenuation beneath the Juan de Fuca plate: Implications for mantle flow and dehydration[J]. Earth and Planetary Science Letters,2018-01-01,496