2013 Fiscal Year Final Research Report
Millennium analysis of mercury content in the North Atlantic sediments during the late Pliocene
Project/Area Number |
24651011
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Research Category |
Grant-in-Aid for Challenging Exploratory Research
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Allocation Type | Single-year Grants |
Research Field |
Environmental dynamic analysis
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Research Institution | Kyushu University |
Principal Investigator |
KITA Itsuro 九州大学, 比較社会文化研究科(研究院), 教授 (10143075)
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Co-Investigator(Renkei-kenkyūsha) |
SATO Tokiyuki 秋田大学, 工学資源学部, 教授 (60241668)
OHNO Masao 九州大学, 大学院比較社会文化研究院, 准教授 (00251413)
KUWAHARA Yoshihiro 九州大学, 大学院比較社会文化研究院, 准教授 (90281196)
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Project Period (FY) |
2012-04-01 – 2014-03-31
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Keywords | マーキュリー / ミレニアム解析 / 氷床拡大縮小 / 氷床の出現・発達期 / ナンノプランクトン / 北大西洋 / 透光帯水塊構造 / IODP |
Research Abstract |
It was clarified that mercury contents in the North Atlantic sediments over the last 1,000,000 years and during a period between 2500 ka and 2550 ka changed with distinct periods of 100,000 and 41,000 years, and 3000 and 5000 years, respectively. The sediment Hg content increased during glacial periods with the increase of ice-rafted debris (IRD), correlating positively with total organic carbon content and inversely with its carbon isotopic ratio and the absolute abundance of surface-dwelling nannoplankton species. These observations suggest that Hg- and IRD-bearing icebergs flowed out to this sea area melted during glacial periods and the increased Hg of photic water is incorporated into the organic matter produced by deep-dwelling phytoplankton in the lower photic zone. Sediment Hg content can be used as a new chemical indicator of enlargement and reduction of ice floes in the northern hemisphere in both orbital and millennium scales
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[Presentation] Millennial-scale rock magnetic variations indicating instability of North Atlantic environments during intensification of northern hemisphere glaciation2013
Author(s)
Ohno, M., Sato M., Kuwahara, Y. Hayashi, T., Miyagawa, C., Kita, I.
Organizer
IAGA 2013 12th Scientific Assembly
Place of Presentation
Fiesta Americana Merida Hotel, Mexico(Poster)
Year and Date
2013-08-26
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