气候变化领域集成服务门户(CCPortal): Mantle and sub-lithosphere mantle gravity maps from the LITHO1.0 global lithospheric model

CCPortal

DOI	10.1016/j.earscirev.2019.05.001
	Mantle and sub-lithosphere mantle gravity maps from the LITHO1.0 global lithospheric model
	Tenzer R.; Chen W.
发表日期	2019
ISSN	00128252
起始页码	38
结束页码	56
卷号	194
英文摘要	Methods for a spherical harmonic analysis and synthesis of global gravitational and lithospheric structure models are applied to compile the mantle and sub-lithospheric mantle gravity maps. Both gravity maps are then interpreted and assessed by means of their accuracy. The mantle gravity map exhibits a gravitational signature that mainly reflects a thermal state of the lithospheric mantle. This is particularly evident over the oceanic lithosphere, with gravity lows along mid-oceanic spreading ridges. The increasing gravity signal with the ocean-floor age is attributed to conductive cooling of the oceanic lithosphere. Gravity lows extend along continental rift systems. Gravity lows also mark active convergent tectonic margins (in Pacific, Mediterranean, and Caribbean). The old, cold and tectonically stable cratonic mantle is typically characterized by gravity highs. A thermal signature of upwelling mantle under mid-oceanic spreading ridges clearly manifests (by gravity lows) also in the sub-lithosphere mantle gravity map. Nevertheless, the overall signature of conductive cooling is less pronounced in this gravity map, and a thermal signature of the asthenosphere under most of the continental lithosphere is weak. This indicates that a lateral thermal gradient within the asthenosphere tends to be weaker than within the overlying lithospheric mantle. The most pronounced feature in this gravity map is the signature of subducted slabs in West Pacific, marked by gravity highs. An antipodal signature of two large low shear-velocity provinces in both mantle gravity maps is absent, while its long-wavelength pattern could clearly be recognized in the free-air gravity map. We explain this finding by the fact that gravity-stripping procedures applied in this study superpose a gravitational signature of an intermediate layer, in this case the lithospheric mantle and the asthenosphere, over a much weaker signature of deeper mantle density heterogeneities. Moreover, the interpretational quality of both mantle gravity maps is considerably worsen by the LITHO1.0 lithospheric model uncertainties, especially within a more complex structure of the continental lithosphere. As a result, some spatial features in presented gravity maps could be artefacts rather than a real gravity signal. Despite accuracy limitations of currently available lithospheric density models, such types of gravity maps provide a useful information for various purposes in geophysics, among others gravimetric interpretations of Earth's inner structure or a separation of gravitational signals from different sources. In geodesy, a primary motivation is related to a compilation of Earth's synthetic density model based on the condition of fulfilling the total mass budget for testing numerical techniques applied in gravimetric forward modelling by means of solving Newton's volume integral. © 2019 Elsevier B.V.
关键词	Asthenosphere Crust Gravity Lithosphere Mantle
英文关键词	asthenosphere; continental lithosphere; crustal structure; geological mapping; gravity field; lithospheric structure; mantle structure; mid-ocean ridge; oceanic lithosphere; seafloor; Atlantic Ocean; Caribbean Sea; Mediterranean Sea; Pacific Ocean
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203570
作者单位	Department of Land Surveying and Geo-Informatics, Hong Kong Polytechnic University, Hong Kong; School of Geomatics Science and Technology, Nanjing Tech University, Nanjing, China
推荐引用方式 GB/T 7714	Tenzer R.,Chen W.. Mantle and sub-lithosphere mantle gravity maps from the LITHO1.0 global lithospheric model[J],2019,194.
APA	Tenzer R.,&Chen W..(2019).Mantle and sub-lithosphere mantle gravity maps from the LITHO1.0 global lithospheric model.Earth Science Reviews,194.
MLA	Tenzer R.,et al."Mantle and sub-lithosphere mantle gravity maps from the LITHO1.0 global lithospheric model".Earth Science Reviews 194(2019).