气候变化领域集成服务门户(CCPortal): Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin

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DOI	10.1016/j.quascirev.2020.106567
	Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin
	Guo Q.; Li B.; Voelker A.H.L.; Kim J.-K.
发表日期	2020
ISSN	0277-3791
卷号	247
英文摘要	Reconstruction of the Mediterranean Outflow Water (MOW) dynamics in the geologic past contributes to exploring its influence on the North Atlantic Ocean circulation and global climate. The middle Pleistocene transition (MPT) is one of the most important characteristics of Quaternary climate change, but until now, research on the MOW variability during this time interval has been limited. To decipher the MOW variability over the last 1.3 myr, this work presents the first continuous and high-resolution (∼2 kyr) foraminiferal stable oxygen and carbon isotopes and benthic foraminiferal records from Integrated Ocean Drilling Program (IODP) Site U1391, which was drilled off the Portuguese margin in the Northeast Atlantic Ocean and is currently bathed by the lower MOW core. Based on spectral analysis results of the foraminiferal δ18O record, the MPT peaked from 0.9 to 0.7 Ma. The ‘epibenthos group’ was previously found attached to elevated substrates only within the MOW current and more abundant at higher current velocities, so the relative abundance of the ‘elevated epibenthos group’ was adopted as an indicator of MOW strength in this study. The MOW indicator suggests that the MOW strengthened during MIS 1, MIS 5, MIS 7, MIS 9, MIS 11, MIS 13, MIS 15, MIS 17, early MIS 18 to late MIS 19, MIS 21, MISs 23–25, MISs 28–30, early MIS 34 to MIS 35, early MIS 36 to late MIS 37 and MIS 40 with a ∼100 kyr cycle. Superimposed on the long-term variability of the MOW current, the ∼41-kyr and ∼20-kyr cyclic fluctuations are also evident, whereby the ∼41-kyr cycle is more significant. The results of cross-spectral analyses indicate that the ∼20-kyr cyclic variation in the MOW intensity was drived by the precession forcing; the ∼41-kyr cyclic variation in the pre- MPT MOW dynamics and the ∼100-kyr cyclic variation in the post-MPT MOW dynamics were strongly controlled by the Earth's obliquity. The variation in the abundance of the elevated epibenthos group was dominated by the ∼41-kyr cycle prior to the MPT and by the ∼100-kyr cycle after the MPT, which suggested there was a MPT-related shift in the MOW dynamics. Benthic δ13C record of the last 0.56 myr shows precessional (23-kyr) and glacial-interglacial (∼100 kyr) cycles, indicating cyclic variations in bottom water ventilation. Enhanced ventilation coincides with precession maxima and reduced ventilation with precession minima. Bottom water was well ventilated by MOW during the interglacial periods and by GNAIW during the glacial periods, and pooly ventilated during the glaical terminations. © 2020 Elsevier Ltd
英文关键词	Benthic foraminifera; Bottom water ventilation; Mediterranean outflow water; Middle pleistocene transition; Stable oxygen and carbon isotopes
语种	英语
scopus关键词	Climate change; Glacial geology; Infill drilling; Oceanography; Spectrum analysis; Ventilation; Cross-spectral analysis; Integrated ocean drilling programs; Interglacial periods; Long-term variability; Mediterranean outflow waters; North Atlantic Ocean Circulation; Northeast Atlantic Ocean; Relative abundance; Dynamics; benthic foraminifera; climate change; global climate; interglacial; marine isotope stage; Ocean Drilling Program; outflow; Pleistocene; Atlantic Ocean; Atlantic Ocean (North); Atlantic Ocean (Northeast); Foraminifera
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151298
作者单位	State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing, 210008, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266061, China; Divisão de Geologia e Georecursos Marinhos, Instituto Português do Mar e da Atmosfera (IPMA), Avenida Doutor Alfredo Magalhães Ramalho 6, Alges1495-165, Portugal; CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, Faro, 8005-139, Portugal; Korean Institute of Ocean Science and Technology, Busan, 49111, South Korea
推荐引用方式 GB/T 7714	Guo Q.,Li B.,Voelker A.H.L.,et al. Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin[J],2020,247.
APA	Guo Q.,Li B.,Voelker A.H.L.,&Kim J.-K..(2020).Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin.Quaternary Science Reviews,247.
MLA	Guo Q.,et al."Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin".Quaternary Science Reviews 247(2020).