1987 Fiscal Year Final Research Report Summary
Three component geomagnetic anomalies in backarc basins (e.g. Japan Seq and Okinawa Trough)
| Project/Area Number |
61460044
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体地球物理学
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| Research Institution | Kobe University |
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Principal Investigator |
ISEZAKI Nobuhiro Dept. Earth Sciences, Faculty of Science, Kobe Univ., Associate Prof., 理学部, 助教授 (60107943)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Three compoenet anomaly / Magnetic anomaly lineation / 背弧海盆 / 海底磁力計 |
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| Research Abstract |
1. Geomagnetic three component anomalies in the Japan Sea
(1) Japan Basin: Three component magnetic survey was conducted by R/V Hakuhomaru and R/V Tanseimaru of ORI of Univ. of Tokyo in June 1987. The detailed feature of geomagnetic anomaly lineations was revealed by the three component anomalies. One of the important results is that magnetization of the Japan Basin seafloor has the north-south declination which does not suggest rotation of the basin.
(2) Yamato Basin: The magnetic survey over 4 seqmounts was conducted through the DELP program in summer 1986. The declinations of magnetization of all 4 seqmounts direct almost due north-south, which suggest no rotation of the basin.
2. Geomagnetic three component anomalies in the Okinawa Trough
In the Iheya depressionm the central part of the Okinawa Trough there are large amplitude geomagnetic anomalies. These anomalies are explained by the seafloor topography with normal magnetization, which suggests that the magnetic source is the young intrusive volcanic rocks in the Brunhes epoch.
3. OBM(Ocean Bottom Magnetometer) survey: An OBM with newly developed detach device was deployed in the north of Nankai Trough and withdrew by an acoustic detach system.
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