Project/Area Number |
05452370
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
Natural disaster science
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Research Institution | TOHOKU UNIVERSITY |
Principal Investigator |
SHUTO Nobuo TOHOKU UNIVERSITY,FUCULTY OF ENGINEERING,DISASTER CONTROL RESEARCH CENTER,Professor, 工学部・災害制御研究センター, 教授 (90055137)
|
Co-Investigator(Kenkyū-buntansha) |
MIURA Satoshi TOHOKU UNIVERSITY,FACULTY OF SCIENCES,OBSERVATION CENTER FOR PREDICTION OF EARTH, 理学部・地震予知・噴火予知観測センター, 助手 (70181849)
IMAMURA Fumihiko TOHOKU UNIVERSITY,FACULTY OF ENGINEERING,DISASTER CONTROL RESEARCH CENTER,Associ, 工学部・災害制御研究センター, 助教授 (40213243)
|
Project Period (FY) |
1993 – 1994
|
Project Status |
Completed (Fiscal Year 1994)
|
Budget Amount *help |
¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 1994: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1993: ¥2,500,000 (Direct Cost: ¥2,500,000)
|
Keywords | Non-seismic tsunami generation / Tsunami generated by a secondary fault / Tsunami generation due to volcanic eruption / 1983 Nihonkai-Chubu earthquake tsunami / 1992 Nicaraguan tsunami / 1993 Hokkaido Nansei-oki earthquake tsunami / 1883 Krakatau tsunami / 1992年ニカラグア津波 / 津波発生 / 断層運動 / 地盤変動 |
Research Abstract |
A tsunami is ususlly considered to be generated by an earthquake. Once fault parameters are given, the initial tsunami profile is calculated with the elastic theory. It is assumed that the vertical displacement of sea bottom is closely related to the fault movement. However, this assumption is not always true. 1) In case of the 1983 Nihonkai-Chubu earthquake composed of two faults, a secondary fault in the north fault and a non-seismic movement are necessary in order to explain earlier arrival of the actual tsunami than the computed tsunami for the major fault movement determined by seismic data. 2) In case of the 1992 Nicaraguan tsunami, in spite of a large tsunami, the earthquake was very weak, as 2 in the JMA intensity scale. Whether this tsunami was generated by the earthquake or by other mechanism was examined. It is concluded that this earthquake was a tsunami earthquake. 3) In case of the 1993 Hokkaido Nansei-oki earthquake, the first tsunami arrived at the western coast of Hokkaido 5 minutes faster than that generated at the place of the fault estimated from seismic data. This strongly suggests that other tsunami generation mechanism than the earthquake should be found in the area between the fault and the coast. 4)The 1883 Krakatau tsunami which was not generated by an earthquake but by a caldera formation was numerically simulated. A method is developed to stably simulate a sudden fall of water at the initial profile.
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