| Project/Area Number |
13640415
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体地球物理学
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| Research Institution | Chiba University |
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Principal Investigator |
NAKANISHI Masao Chiba University, Graduate School of Science and Technology, Associate Professor, 大学院・自然科学研究科, 助教授 (80222165)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2001: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | magnetic anomaly lineation / Mesozoic / spreading rate / skewness parameter / Pacific Plate / 磁気異常 / 北西太平洋 |
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| Research Abstract |
The Mesozoic magnetic lineation map, which had been made by Nakanishi et al.(1992), was revised using available underway geophysical data. The magnetic lineations were improved in the following areas,
(1) Ontong Java Plateau
(2) Nova-Canton Trough
(3) Japan, Izu-Ogasawara, and Mariana trenches
The cruise in the southern Mariana Trench was conducted in 2002 October by R/V KAIREI to get geophysical data. The result of the cruise implies that the subducting plate at the trench is a part of the Pacific Plate, although it had been thought to be the other plate.
The skewness parameters of magnetic anomaly lineations were determined in more detailed than previous works. The results exposed that the rotation of the microplate near Pacific-Farallon-Phoenix triple junction occurred and that the intra-plate volcanism occurred in Nauru Basin.
The dependence of anomalous skewness on spreading rates was examined using magnetic data in the Gulf of Aden, where there is a slow spreading system. The result shows that the dependence is less effective for this study.
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