气候变化领域集成服务门户(CCPortal): Convective Erosion of a Primordial Stratification Atop Earth's Core

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DOI	10.1029/2020GL087109
	Convective Erosion of a Primordial Stratification Atop Earth's Core
	Bouffard M.; Landeau M.; Goument A.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:14
英文摘要	Seismic and geomagnetic observations suggest the presence of a stratified layer atop Earth's core. Previous laboratory experiments showed that this layer could be primordial, produced by a collision between the primitive Earth and a giant impactor. However, paleomagnetic data require turbulent flow motions in the core for the last 3.4 Ga. Such flows can erode an existing stratification. It is therefore unclear whether a primordial stratification still exists nowadays. Here, we use numerical simulations to investigate the erosion by thermal convection of a chemical layer atop Earth's core. Our scaling law predicts that a primordial layer thicker than 1 km with a density anomaly above 0.01% can survive 4.5 Ga of convective erosion. We conclude that the observed present-day stratification could be a vestige of core formation. We also observe strong double-diffusive flows in the layer. These might reconcile the existence of a stratification with the present-day structure of the geomagnetic field. ©2020. The Authors.
英文关键词	Geomagnetism; Heat convection; Density anomalies; Double diffusive; Geomagnetic fields; Geomagnetic observation; Laboratory experiments; Paleomagnetic data; Stratified layers; Thermal convections; Erosion; collision; geomagnetic field; simulation; stratification; thermal convection; turbulent flow
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170080
作者单位	Max Planck Institute for Solar System Research, Göttingen, Germany; Aix Marseille Univ, CNRS, Centrale Marseille, IRPHE, Marseille, France; Institut de physique du globe de Paris, CNRS, Université de Paris, Paris, France; Département Sciences de la Terre et de l'Univers, Université de Nantes, Nantes, France
推荐引用方式 GB/T 7714	Bouffard M.,Landeau M.,Goument A.. Convective Erosion of a Primordial Stratification Atop Earth's Core[J],2020,47(14).
APA	Bouffard M.,Landeau M.,&Goument A..(2020).Convective Erosion of a Primordial Stratification Atop Earth's Core.Geophysical Research Letters,47(14).
MLA	Bouffard M.,et al."Convective Erosion of a Primordial Stratification Atop Earth's Core".Geophysical Research Letters 47.14(2020).