DOI: 10.1002/2014GL061362
论文题名: Effects of low-viscosity post-perovskite on the stability and structure of primordial reservoirs in the lower mantle
作者: Li Y. ; Deschamps F. ; Tackley P.J.
刊名: Geophysical Research Letters
ISSN: 0094-9660
EISSN: 1944-9391
出版年: 2014
卷: 41, 期: 20 起始页码: 7089
结束页码: 7097
语种: 英语
英文关键词: mantle convection
; post-perovskite
; viscosity
Scopus关键词: Perovskite
; Stability
; Structural geology
; Viscosity
; Core-mantle boundary
; Lowermost mantle
; Mantle convection
; Mantle temperatures
; Numerical experiments
; Post-perovskite
; Spherical geometries
; Viscosity reduction
; Heat flux
; core-mantle boundary
; heat flux
; lower mantle
; mantle convection
; perovskite
; reservoir
; slab
; topography
; viscosity
英文摘要: We performed numerical experiments of thermochemical convection in 3-D spherical geometry to investigate the effects of a low viscosity of post-perovskite (pPv) on the stability and structure of primordial reservoirs of dense material in the lower mantle of the Earth. Our results show that weak pPv (1000× viscosity reduction in regions containing pPv) strongly increases the core-mantle boundary (CMB) heat flux. The volume-averaged mantle temperature with weak pPv is slightly higher than that with regular pPv, except in the lowermost mantle. This is because weak pPv weakens the base of the cold downwellings, allowing cold slabs to spread more easily and broadly along the CMB. The stability and size of the dense reservoirs is not substantially altered by weak pPv. In the weak pPv case, slabs spreading along the CMB slightly decreases the stability of dense reservoirs, i.e., the amount of dense material entrained upward is slightly larger than in the regular pPv case (i.e., viscosity of pPv identical to that of perovskite). Furthermore, the topography and steepness of these reservoirs slightly increase. However, as in the regular pPv case, the dense reservoirs are maintained over periods of time comparable to the age of the Earth. Key Points With weak pPv, cold slabs spread more easily and broadly along the CMBThis increases the CMB heat flux and the steepness of the primordial reservoirsThe stability of primordial reservoirs is not substantially altered by weak pPv ©2014. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911376703&doi=10.1002%2f2014GL061362&partnerID=40&md5=e7072869a8bb0dc49bab8d06ae07bb07
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/6924
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Geophysics, ETH Zurich, Zurich, Switzerland
Recommended Citation:
Li Y.,Deschamps F.,Tackley P.J.. Effects of low-viscosity post-perovskite on the stability and structure of primordial reservoirs in the lower mantle[J]. Geophysical Research Letters,2014-01-01,41(20).