气候变化领域集成服务门户(CCPortal): Instability of the African large low-shear-wave-velocity province due to its low intrinsic density

CCPortal

DOI	10.1038/s41561-022-00908-3
	Instability of the African large low-shear-wave-velocity province due to its low intrinsic density
	Yuan, Qian; Li, Mingming
发表日期	2022
ISSN	1752-0894
EISSN	1752-0908
起始页码	334
结束页码	+
卷号	15 期号:4 页码:17
英文摘要	The seismic anomaly in the lowermost mantle beneath Africa is greater in height and less stable than its Pacific counterpart because of its lower density, according to numerical simulations of the anomalies as thermochemical piles. Seismic observations have revealed two seismic anomalies in the lowermost mantle, one beneath Africa and the other beneath the Pacific Ocean, named large low-shear-wave-velocity provinces. These structures are generally considered to be intrinsically dense thermochemical piles that influence mantle and core processes. However, the controls on their morphology, including their relative height difference and their stability, remain unclear. Here we analyse published global shear-wave tomography models, which show that the African anomaly is about 1,000 km greater in height than the Pacific anomaly. With our numerical simulations, we find that the maximum height a thermochemical pile can reach is more controlled by its density and the surrounding mantle viscosity, and less so by its own viscosity and volume. Comparing these findings suggests that the African anomaly has a relatively lower density and thus may be less stable than the Pacific anomaly, implying the two anomalies have different compositions, dynamics and evolution histories.
学科领域	Geosciences, Multidisciplinary
语种	英语
WOS研究方向	Geology
WOS记录号	WOS:000767011500001
来源期刊	NATURE GEOSCIENCE
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/272644
作者单位	Arizona State University; Arizona State University-Tempe
推荐引用方式 GB/T 7714	Yuan, Qian,Li, Mingming. Instability of the African large low-shear-wave-velocity province due to its low intrinsic density[J],2022,15(4):17.
APA	Yuan, Qian,&Li, Mingming.(2022).Instability of the African large low-shear-wave-velocity province due to its low intrinsic density.NATURE GEOSCIENCE,15(4),17.
MLA	Yuan, Qian,et al."Instability of the African large low-shear-wave-velocity province due to its low intrinsic density".NATURE GEOSCIENCE 15.4(2022):17.