气候变化领域集成服务门户(CCPortal): Contrasting opacity of bridgmanite and ferropericlase in the lowermost mantle: Implications to radiative and electrical conductivity

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DOI	10.1016/j.epsl.2021.116871
	Contrasting opacity of bridgmanite and ferropericlase in the lowermost mantle: Implications to radiative and electrical conductivity
	Lobanov S.S.; Soubiran F.; Holtgrewe N.; Badro J.; Lin J.-F.; Goncharov A.F.
发表日期	2021
ISSN	0012821X
卷号	562
英文摘要	Earth's lowermost mantle displays complex geological phenomena that likely result from its heterogeneous physical interaction with the core. Geophysical models of core-mantle interaction rely on the thermal and electrical conductivities of appropriate geomaterials which, however, have never been probed at representative pressure and temperature (P-T) conditions. Here we report on the opacity of single crystalline bridgmanite and ferropericlase and link it to their radiative and electrical conductivities. Our results show that light absorption in the visible spectral range is enhanced upon heating in both minerals but the rate of change in opacity with temperature is a factor of six higher in ferropericlase. As a result, bridgmanite in the lowermost mantle is moderately transparent while ferropericlase is highly opaque. Our measurements support previous indirect estimates of low (< 1 W/m/K) and largely temperature-independent radiative conductivity in the lowermost mantle. This implies that the radiative mechanism has not contributed significantly to cooling the Earth's core throughout the geologic time. Opaque ferropericlase is electrically conducting and mediates strong core-mantle electromagnetic coupling, explaining the intradecadal oscillations in the length of day, low secular geomagnetic variations in Central Pacific, and the preferred paths of geomagnetic pole reversals. © 2021 Elsevier B.V.
关键词	bridgmanite core-mantle boundary ferropericlase high pressure thermal conductivity time-resolved spectroscopy
英文关键词	Electric conductivity; Light absorption; Opacity; Thermal conductivity; Bridgmanite; Core-mantle boundary; Electrical conductivity; Ferropericlase; Geological phenomenon; High pressure; Lowermost mantle; Radiative conductivity; Thermal; Time-resolved spectroscopy; Geomagnetism; core-mantle boundary; crystalline rock; electrical conductivity; geomagnetic field; lower mantle; P-T conditions; periclase; spectroscopy; thermal conductivity
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203197
作者单位	GFZ German Research Center for Geosciences, Section 3.6, Telegrafenberg, Potsdam, 14473, Germany; Earth and Planets Laboratory, Carnegie Institution of Washington, Washington, DC, 20015, United States; École Normale Supérieure de Lyon, Université Lyon 1, Laboratoire de Géologie de Lyon, CNRS UMR5276, Lyon Cedex 07, 69364, France; Université de Paris, Institut de physique du globe de Paris, CNRS, Paris, 75005, France; Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX 78712, United States
推荐引用方式 GB/T 7714	Lobanov S.S.,Soubiran F.,Holtgrewe N.,et al. Contrasting opacity of bridgmanite and ferropericlase in the lowermost mantle: Implications to radiative and electrical conductivity[J],2021,562.
APA	Lobanov S.S.,Soubiran F.,Holtgrewe N.,Badro J.,Lin J.-F.,&Goncharov A.F..(2021).Contrasting opacity of bridgmanite and ferropericlase in the lowermost mantle: Implications to radiative and electrical conductivity.Earth and Planetary Science Letters,562.
MLA	Lobanov S.S.,et al."Contrasting opacity of bridgmanite and ferropericlase in the lowermost mantle: Implications to radiative and electrical conductivity".Earth and Planetary Science Letters 562(2021).