Investigating long-term variation in intensity of the paleomagnetic field during a period of low reversal frequency - new constraint on the outer core process
Project/Area Number |
16H04043
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Solid earth and planetary physics
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Research Institution | Kochi University |
Principal Investigator |
Yamamoto Yuji 高知大学, 教育研究部総合科学系複合領域科学部門, 教授 (00452699)
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Co-Investigator(Kenkyū-buntansha) |
小玉 一人 同志社大学, 研究開発推進機構, 嘱託研究員 (00153560)
山崎 俊嗣 東京大学, 大気海洋研究所, 教授 (80344125)
小田 啓邦 国立研究開発法人産業技術総合研究所, 地質調査総合センター, 上級主任研究員 (90356725)
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Project Period (FY) |
2016-04-01 – 2020-03-31
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Project Status |
Completed (Fiscal Year 2019)
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Budget Amount *help |
¥17,810,000 (Direct Cost: ¥13,700,000、Indirect Cost: ¥4,110,000)
Fiscal Year 2019: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2018: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2017: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2016: ¥8,320,000 (Direct Cost: ¥6,400,000、Indirect Cost: ¥1,920,000)
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Keywords | 地磁気 / 古地磁気 |
Outline of Final Research Achievements |
Paleo- and rock magnetic measurements were conducted on sedimentary cores recovered at four sites in the northwest Atlantic during the Integrated Ocean Drilling Program Expedition 342. Continuous variation of relative paleointensity (RPI) of the geomagnetic field could be estimated from the cores at the two sites, for a period of 38-50 million years ago. This is the oldest RPI record reported so far. The estimated RPI showed repeated large fluctuations, intensity minima at chron boundaries, and so on. These characters are the same as those reported in the RPI of the last 2-3 million years.
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Academic Significance and Societal Importance of the Research Achievements |
地磁気は、その起源である外核内対流はマントル・外核境界の熱境界条件の影響を大きく受け、逆転頻度を大きく変化させてきた。これまでは、逆転頻度が100万年あたり4-5回という、地球史で見れば「現在」の熱境界条件下にあたる過去約200-300万年間のRPI連続変動が解明されるに留まっていた。本研究では、100万年あたり2回という低逆転頻度を示す、「現在」とは熱境界条件が大きく異なる期間(約3800万年前~約5000万年前)のRPI連続変動を推定することができた。世界初であるとともに、世界最古の記録である。
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Report
(5 results)
Research Products
(23 results)
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[Journal Article] Datareport: Updated magnetostratigraphy for IODP Sites U1403, U1408, U1409 and U14102018
Author(s)
Yamamoto Y., Fukami H., Lippert P., Taniguchi W.
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Journal Title
In Norris, R.D., Wilson, P.A., Blum, P., and the Expedition 342 Scientists, Proceedings of the Integrated Ocean Drilling Program
Volume: 342
Pages: 207-207
DOI
Related Report
Peer Reviewed / Open Access / Int'l Joint Research
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[Journal Article] Towards a robust and consistent middle Eocene astronomical timescale2018
Author(s)
Boulila, S., Vahlenkamp, M., De Vleeschouwer, D., Laskar, J., Yamamoto, Y., Palike, H., Turner, S.K., Sexton, P.F., Westerhold, T., Rohl, U.
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Journal Title
Earth Planet. Sci. Lett.
Volume: 486
Pages: 94-107
DOI
Related Report
Peer Reviewed / Int'l Joint Research
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