1995 年 48 巻 2 号 p. 229-233
Ten years after the 1983 Nihonkai-Chubu tsunami, the 1993 Hokkaido Nansei-Oki tsunami (magnitude, m=3) hit Okushiri Is., Oshima Peninsula and other regions, Killing 231 people by tsunami and landslide. The distribution pattern of tsunami hfeights is different from that of the 1741 Oshima-Oki tsunami (m=3.5). This paper presents the distribution of cumulative energy, ∑H2, for each 150km segment alomg the Japan Sea coast for the time intervals of the recent 100-year (1894-1994) and of 1600 to 1893 (historical tsunamis). The amount of cumulative energy for the recent and historical tsunamis is largest at the Akita and Oshima-Tsugaru regions, respectively. The cumulative energy at the Akita, Shakotan and other regions for the recent 100-year tsunamis exceeds that of the historical tsunamis. On the contrary, the cumulative energy in the Oshima-Tsugaru and Niigata-Ishikawa regions for the recent tsunamis are small compared with those of the historical tsunamis. Precaution must be paid to these regions for seismic gap may exist there. The total tsunamigenic energy in the Japan Sea comprises 24% of that due to tsunamis in the whole Japan.