DOI: 10.1016/j.epsl.2018.06.027
Scopus记录号: 2-s2.0-85049084903
论文题名: High-pressure single-crystal elasticity of wadsleyite and the seismic signature of water in the shallow transition zone
作者: Buchen J. ; Marquardt H. ; Speziale S. ; Kawazoe T. ; Boffa Ballaran T. ; Kurnosov A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 498 起始页码: 77
结束页码: 87
语种: 英语
英文关键词: high-pressure
; mantle transition zone
; seismic discontinuity
; single-crystal elasticity
; wadsleyite
Scopus关键词: Elasticity
; Hydration
; Iron
; Seismic waves
; Seismology
; Shear waves
; Velocity
; Wave propagation
; Degrees of hydration
; High pressure
; Impedance contrast
; Mantle transition zone
; Nominally anhydrous minerals
; Seismic discontinuities
; Seismic signatures
; Wadsleyite
; Single crystals
英文摘要: Earth's transition zone at depths between 410 km and 660 km plays a key role in Earth's deep water cycle since large amounts of hydrogen can be stored in the nominally anhydrous minerals wadsleyite and ringwoodite, (Mg,Fe)2SiO4. Previous mineral physics experiments on iron-free wadsleyite proposed low seismic velocities as an indicative feature for hydration in the transition zone. Here we report simultaneous sound wave velocity and density measurements on iron-bearing wadsleyite single crystals with 0.24 wt-% H2O. By comparison with earlier studies, we show that pressure suppresses the velocity reduction caused by higher degrees of hydration in iron-bearing wadsleyite, ultimately leading to a velocity cross-over for both P-waves and S-waves. Modeling based on our experimental results shows that wave speed variations within the transition zone as well as velocity jumps at the 410-km seismic discontinuity, both of which have been used in previous work to detect mantle hydration, are poor water sensors. Instead, the impedance contrast across the 410-km seismic discontinuity that is reduced in the presence of water can serve as a more robust indicator for hydrated parts of the transition zone. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109758
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: Bayerisches Geoinstitut, Universität Bayreuth, Bayreuth, 95440, Germany; Department of Earth Sciences, University of Oxford, Oxford, OX1 3AN, United Kingdom; Deutsches GeoForschungsZentrum, Potsdam, 14473, Germany; Department of Earth and Planetary Systems Science, Hiroshima University, Hiroshima, 739-8526, Japan
Recommended Citation:
Buchen J.,Marquardt H.,Speziale S.,et al. High-pressure single-crystal elasticity of wadsleyite and the seismic signature of water in the shallow transition zone[J]. Earth and Planetary Science Letters,2018-01-01,498