津軽海峡から日本海に伝播する津波の様相
1992 年 45 巻 2 号 p. 169-176
詳細
1992 年 45 巻 2 号 p. 169-176
Adding to the Russian data, the behaviors of the 1952 Kamchatka, 1960 Chile and the 1968 Tokachi-Oki tsunamis propagated into the Japan Sea from the Tsugaru Straits are investigated. Wave-heights of the 1960 Chile tsunami reached 1.0-1.5m at the West Hokkaido and Tsugaru coasts. The ratio of amplitude of these coasts to that of Hakodate was 0.2-0.4. For the 1952 Kamchatka tsunami, the ratio at Nakhodka was 0.3. While, wave-heights at the West Hokkaido to Tsugaru coasts for the 1968 Tokachi-Oki tsunami being the short period decreased one-tenth high at Hakodate. Wave-heights observed with the wave-periods of 70min and 50min for the Chile and Kamchatka tsunamis are largest, respectively. The maximum wave of the Kamchatka and Chile tsunamis occurred 12 hours or more late after the initial wave, and the undulation continued for two days. According to the refraction diagram, the wave-rays concentrate at the Primorskiy and Korean coasts, but most of the energy trapped on the shelf of Japanese coast. For the long-period tsunamis, it is indispensable to take precautions against the effet of currents.
