1973 年 26 巻 1 号 p. 1-7
Based on the historical records of the tsunamis generated in the vicinity of Japan during the period of about 300 years, 1600-1893, the geographic distributions of tsunami height are investigated. The energy distribution for the historical tsunamis is compared with that of the tsunamis generated during the last 79 years, 1894-1972. Difference of the energy distribution is as follows: 1) The amount of tsunami energy received in the Nankaido region before 1893 is larger than that in the Sanriku region. 2) In the S. Hokkaido, S. Kanto and Tokaido regions, the wave energy received from historical tstnamis is conspicuously large. In the region from Fukushima to Boso Peninsula, the energy received since 1600 is relatively small and the pattern of energy distribution is similar to that of recent tsunamis.
In order to predict travel times, the iso-lines of tsunami travel time are drawn from the whole of the Japanese coasts. The uncertainty of the diagram may be within ±3min, judging from the observed travel times.