2014 Fiscal Year Final Research Report
Early warning system of tsunami by observing tsunamigenic ionospheric hole
| Project/Area Number |
24310129
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Partial Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Natural disaster science
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| Research Institution | Tokyo Gakugei University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
KAKINAMI Yoshihiro 高知工科大学, 工学部, 助教 (00437758)
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | 津波 / 地震 / 電離圏 / 津波電離圏ホール |
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| Outline of Final Research Achievements |
Low frequency acoustic waves, termed infrasonic waves, are excited by the sudden displacement of ground and sea surface at large earthquake (EQ) and tsunami. When the acoustic waves propagate into the ionosphere, they disturb the ionospheric plasma. The plasma disturbance has been detected by the measurement of total electron contents (TEC) between a satellite of Global Positioning Systems (GPS) and its receivers on the ground. In addition to the acoustic waves, a TEC depression lasting for a few minutes to tens of minutes, termed tsunamigenic ionospheric hole (TIH), is formed by the large EQ with tsunami above the tsunami source area. The largest TEC depression appears 10 to 20 minutes after the main shock. In this study, we show the quantitative relation between the initial tsunami height and the TEC depression rate caused by the TIH. Accordingly, the ionospheric TEC measurement is applicable to an early warning system of tsunami.
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| Free Research Field |
地球電磁気学
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