气候变化领域集成服务门户(CCPortal): Internal structure of ultralow-velocity zones consistent with origin from a basal magma ocean

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DOI	10.1038/s41561-021-00871-5
	Internal structure of ultralow-velocity zones consistent with origin from a basal magma ocean
	Pachhai S.; Li M.; Thorne M.S.; Dettmer J.; Tkalčić H.
发表日期	2022
ISSN	1752-0894
卷号	15 期号:1
英文摘要	Seismological observations reveal patches of low-velocity anomalies at the core–mantle boundary known as ultralow-velocity zones. Despite recent advances, their origin and dynamic link to the lowermost mantle remain unclear. Here we employ seismic data analysis and high-resolution geodynamic modelling to study the origin of ultralow-velocity zones beneath the Coral Sea between Australia and New Zealand. The analysis of core-reflected waveforms with rigorous estimation of Bayesian uncertainties shows strong evidence of stratified density increases (~30%) and shear-wave velocity decreases (~50%) within the ultralow-velocity zones. These zones thin on two sides and occur at the edge of the Pacific large low-shear-velocity province. Geodynamic modelling demonstrates that these features are consistent with the presence of compositional heterogeneities within the ultralow-velocity zones that may be caused by the remnants of Earth’s early differentiation. We conclude that small-scale structures that are compositionally distinct from their surroundings reside at the bottom of the mantle without full homogenization, throughout Earth’s history. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	Bayesian analysis; magma; mantle; S-wave; seismic data; seismic velocity; waveform analysis; Australia; Coral Sea; New Zealand; Pacific Ocean
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/250810
作者单位	Research School of Earth Sciences, The Australian National University, Canberra, ACT, Australia; Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, United States; School of Earth and Space Exploration, Arizona State University, Tempe, AZ, United States; Department of Geoscience, University of Calgary, Calgary, AB, Canada
推荐引用方式 GB/T 7714	Pachhai S.,Li M.,Thorne M.S.,et al. Internal structure of ultralow-velocity zones consistent with origin from a basal magma ocean[J],2022,15(1).
APA	Pachhai S.,Li M.,Thorne M.S.,Dettmer J.,&Tkalčić H..(2022).Internal structure of ultralow-velocity zones consistent with origin from a basal magma ocean.Nature Geoscience,15(1).
MLA	Pachhai S.,et al."Internal structure of ultralow-velocity zones consistent with origin from a basal magma ocean".Nature Geoscience 15.1(2022).