气候变化领域集成服务门户(CCPortal): Asthenospheric low-velocity zone consistent with globally prevalent partial melting

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DOI	10.1038/s41561-022-01116-9
	Asthenospheric low-velocity zone consistent with globally prevalent partial melting
	Hua, Junlin; Fischer, Karen M.; Becker, Thorsten W.; Gazel, Esteban; Hirth, Greg
发表日期	2022
ISSN	1752-0894
EISSN	1752-0908
页码	21
英文摘要	The asthenosphere plays a fundamental role in present-day plate tectonics as its low viscosity controls how convection in the mantle below it is expressed at the Earth's surface above. The origin of the asthenosphere, including the role of partial melting in reducing its viscosity and facilitating deformation, remains unclear. Here we analysed receiver-function data from globally distributed seismic stations to image the lower reaches of the asthenospheric low-seismic-velocity zone. We present globally widespread evidence for a positive seismic-velocity gradient at depths of similar to 150 km, which represents the base of a particularly low-velocity zone within the asthenosphere. This boundary is most commonly detected in regions with elevated upper-mantle temperatures and is best modelled as the base of a partially molten layer. The presence of the boundary showed no correlation with radial seismic anisotropy, which represents accumulated mantle strain, indicating that the inferred partial melt has no substantial effect on the large-scale viscosity of the asthenosphere. These results imply the presence of a globally extensive, partially molten zone embedded within the asthenosphere, but that low asthenospheric viscosity is controlled primarily by gradual pressure and temperature variations with depth. A partially molten low-seismic-velocity zone in the asthenosphere is globally prevalent, but partial melting is not the primary control of low asthenospheric viscosity, according to analysis of seismic waves travelling through the mantle.
学科领域	Geosciences, Multidisciplinary
语种	英语
WOS研究方向	Geology
WOS记录号	WOS:000926378400001
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/272460
作者单位	Brown University; University of Texas System; University of Texas Austin; University of Texas System; University of Texas Austin; University of Texas System; University of Texas Austin; Cornell University
推荐引用方式 GB/T 7714	Hua, Junlin,Fischer, Karen M.,Becker, Thorsten W.,et al. Asthenospheric low-velocity zone consistent with globally prevalent partial melting[J],2022:21.
APA	Hua, Junlin,Fischer, Karen M.,Becker, Thorsten W.,Gazel, Esteban,&Hirth, Greg.(2022).Asthenospheric low-velocity zone consistent with globally prevalent partial melting.NATURE GEOSCIENCE,21.
MLA	Hua, Junlin,et al."Asthenospheric low-velocity zone consistent with globally prevalent partial melting".NATURE GEOSCIENCE (2022):21.