TSUNAMI GENERATION WITHOUT SHAKING DUE TO EARTHQUAKES.

不会因地震而产生海啸。

基本信息

批准号：
05452370
负责人：
SHUTO Nobuo
金额：
$ 2.82万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05452370/
关键词：
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

项目摘要

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.

海啸被认为是由地震产生的。一旦给出了故障参数，就会使用弹性理论计算初始海啸。假定海底的垂直位移与断层运动密切相关。然而，这个假设并不总是正确的。1）在1983年的Nihonkai-Chubu地震中，必须是两个断层组成的，北部断层的次要断层和非断层运动是必要的比通过地震数据确定的主要断层运动的计算出的海啸。2）如果1992年尼加拉瓜海啸，尽管有大海啸，地震非常弱，在JMA强度量表中为2。是否检查了地震或其他机制产生这种海啸。得出的结论是，这场地震是海啸地震。3）如果1993年的北海道nansei-oki地震，第一批海啸到达北海道的西部海岸，比从地震数据中估计的位置产生的时间快5分钟。。这强烈表明，除地震以外的其他海啸生成机制应在断层和海岸之间的区域中找到。4）1883年的Krakatau海啸并非由地震产生，而是通过火山口层产生的。开发了一种方法来稳定模拟在初始特征下突然掉落的水。