HOKKAIDO NANSEI-OKI EARTHQUAKE TSUNAMI AND DISASTER PREVENTION.

北海道南西冲地震海啸与防灾。

基本信息

批准号：
06302077
负责人：
SHUTO Nobuo
金额：
$ 5.82万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Co-operative Research (A)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06302077/
关键词：
Tsunami Tsunami disaster prevention Long wave trapped mode Impulsive force driftwood Evacuation manual

项目摘要

1) Based upon a re-analysis of long-period (20-50 seconds) surface waves, time-and space-distributions of dislocation of the 1993 earthquake are determined. Total earthquake moment amounts to 6.5 x 10^<20> Nm. Moment is large at three points ; shallow point near the epicenter, deep point at the southern edge of the north fault and the whole south fault. A large upheaval near Okushiri island is concluded from the analysis.2) A theory of entraptment of long waves around a conical island is derived. Theoretical results are compared with the numerical and hydraulic experiments. The theory is applied to the 1993 tsunami, and the runup distribution around Okushiri island is explained except for Monai where the maximum runup was found and except for Hamatsumae where runup of 20 m was found although the village is in the sheltered area.3) In order to simulate the high runup at Hamatsumae, the most important is the location of the south fault and its strike relative to the axis of the Okushiri Spur. The spatial grid as fine as 50 m is necessary. In order to simulate the maximum runup at Monai which was obtained at the bottom of a narrow valley, the spatial grid as fine as 5 m is used. The runups at the two places are well simulated.4) Driftwood and floated fishing boats showed a destructive effect on houses. Theories derived on several assumption are used to determined the shape of formulas, and the coefficients are fixed by experiments of large-scale. The formulas for practical use are thus obtained for the first time.5) Problems and difficulties in an emergency are learned from recent experiences and reviewed carefully for establishing an evacuation manual. An example of tsunami hazard map is obtained, based upon the yearly-change of earthquake generation probability, magnitude of earthquakes, assumed position of faults and probability of the highest tsunami height.

1）基于对长周期（20-50秒）表面波的重新分析，确定了1993年地震的时间和空间分布。总地震矩达到6.5 x 10^<20> nm。力矩在三个方面很大；较浅的点附近，北断层的南部边缘和整个南断裂。从分析中得出结论。将理论结果与数值和液压实验进行了比较。该理论适用于1993年的海啸，除了发现最大奔跑的Monai外，还解释了Okushiri岛周围的奔跑分布，除了在庇护所区域中发现了20 m的Hamatsumae，但在庇护所（3）中发现了20m。3）为了模拟Hamatsumae的高跑步，最重要的是南断层的位置及其罢工相对于Okushiri Spur的轴。需要50 m的空间网格。为了模拟在狭窄山谷底部获得的Monai的最大升压，使用的空间网格被罚款至5 m。这两个地方的奔跑都得到了很好的模拟。4）浮木和漂浮的渔船对房屋显示出破坏性的影响。在几个假设上得出的理论用于确定公式的形状，并且系数通过大规模实验固定。因此，第一次获得了实际使用的公式。5）从最近的经验中学到了紧急情况和困难，并仔细审查以制定疏散手册。基于地震产生概率，地震幅度，假定断层的位置以及最高海啸高度的概率，获得了海啸危害图的示例。