Hyoei Noto
The Idea about the model of tsunami generation judgment for news flash
Tokuzo Hosoyamada, Naoyuki Inukai
One of the biggest reasons of tsunami generation is earthquake at the bottom of the sea. Because of that, the places of high probability of tsunami generation are correspondent to the places of high probability of earthquakes. Practically speaking, more than 80% of tsunami generation occurred at the Pacific coast, for example, Japan, the Kurile Islands, Aleutian, Alaska, Mexico, Peru, and Chile (the circum-Pacific earthquake belt). In Japan, we sometimes have suffered heavy damages of tsunami; so many scientists have researched on the tsunami. Iida, one of the most famous researchers of tsunami and earthquake, said that earthquakes do not always occur tsunami, and the size of tsunami depends on both the magnitude of earthquakes and the depth of earthquake¡Çs hypocenters. In addition, he proposed the formula M < 0.017D + 6.42. According to that formula, earthquakes are not cause of tsunami in the area of M < 0.017D + 6.42. In other words, when the magnitude of earthquakes is 6.42 or less, earthquakes do not occur tsunami.
For past 80 years, although we have thought that earthquakes that are magnitude less than 6.42 do not occur tsunami, many tsunamis have been generated by them in fact. From a chronological point of view, in 1950¡Çs, when Iida suggested the formula, M < 0.017D + 6.42 showed us that most earthquakes that were less than 6.42 did not occur tsunamis; however, between in 1960¡Çs and 2000¡Çs, many these earthquakes generated tsunamis against that formula.
In my paper, I researched the relationship between the magnitude of earthquakes and the depth of earthquake¡Çs hypocenters again. In addition, using that relationship, I newly suggested the formula that is based on an idea of a regression line to Y of X and a rate of divergence. The formula is M = 0.0051D + 6.21. It means that earthquakes that are magnitude less than 6.21 are not caused by tsunami.
Please use "previous botton" to return the previous page