气候变化领域集成服务门户(CCPortal): A dynamic lithosphere–asthenosphere boundary near the equatorial Mid-Atlantic Ridge

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DOI	10.1016/j.epsl.2021.116949
	A dynamic lithosphere–asthenosphere boundary near the equatorial Mid-Atlantic Ridge
	Rychert C.A.; Tharimena S.; Harmon N.; Wang S.; Constable S.; Kendall J.M.; Bogiatzis P.; Agius M.R.; Schlaphorst D.
发表日期	2021
ISSN	0012821X
卷号	566
英文摘要	In plate tectonic theory a weak asthenosphere is required to facilitate the motions of the rigid plates. Partial melt could weaken the mantle, in turn impacting convection, but to date the existence of persistent melt has remained controversial. A wide range of scenarios has been reported in terms of the location, amount and pathways of melt. Here we use data collected by 39 ocean bottom seismometers deployed near the equatorial Mid-Atlantic Ridge on 0 to 80 Myr old seafloor. We calculate S-to-P (Sp) receiver functions and perform waveform modeling. We jointly interpret with shear-wave velocity tomography from surface waves and magnetotelluric (MT) imaging to take advantage of a range of resolutions and sensitivities and illuminate the structure of the oceanic lithosphere and the underlying asthenosphere. We image a tectonic plate thickness that increases with age in one location but undulates in another location. We infer thin and slightly thicker melt channels and punctuated regions of ascending partial melt several hundred kilometers off the ridge axis. This suggests melt persists over geologic timescales, although its character is dynamic, with implications for the lithosphere–asthenosphere boundary (LAB) and the driving forces of the plates. Ascending melt intermittently feeds melt channels at the base of the plate. The associated melt-enhanced buoyancy increases the influence of ridge-push in driving plate motions, whereas the channelized melt reduces the resistance of the plates to motion. Therefore, melt dynamics may play a larger role in controlling plate tectonics than previously thought. © 2021 Elsevier B.V.
关键词	melt dynamics Mid-Atlantic Ridge oceanic lithosphere–asthenosphere boundary plate tectonics receiver functions seismology
英文关键词	Location; Plates (structural components); Seismographs; Shear flow; Shear waves; Surface waves; Tectonics; Wave propagation; Lithosphere-asthenosphere boundary; Melt dynamics; Mid Atlantic Ridge; Oceanbottom seismometers (OBS); Oceanic lithosphere–asthenosphere boundary; Partial melt; Receiver functions; Rigid plate; Sea floor; Waveform modeling; Seismology; asthenosphere; ocean bottom seismometer; oceanic lithosphere; P-wave; plate tectonics; S-wave; seismic tomography; seismology; waveform analysis; Atlantic Ocean; Mid-Atlantic Ridge
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203277
作者单位	Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton Waterfront Campus, United Kingdom; Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Austria; Department of Electronic Systems, Norwegian University of Science and Technology, Norway; Scripps Institution of Oceanography, University of California, San Diego, San Diego, CA, United States; Earth Sciences, University of Oxford, United Kingdom; Department of Sciences, University of Roma Tre, Rome, Italy; Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa, 1749-016, Portugal
推荐引用方式 GB/T 7714	Rychert C.A.,Tharimena S.,Harmon N.,等. A dynamic lithosphere–asthenosphere boundary near the equatorial Mid-Atlantic Ridge[J],2021,566.
APA	Rychert C.A..,Tharimena S..,Harmon N..,Wang S..,Constable S..,...&Schlaphorst D..(2021).A dynamic lithosphere–asthenosphere boundary near the equatorial Mid-Atlantic Ridge.Earth and Planetary Science Letters,566.
MLA	Rychert C.A.,et al."A dynamic lithosphere–asthenosphere boundary near the equatorial Mid-Atlantic Ridge".Earth and Planetary Science Letters 566(2021).