概要 |
The Tsunami which struck the shores of the Okinawa Island in the morning of May 24, 1960, was the most destructive and violent, in the history of the island. 3 persons were drowned, about 1400 houses ...were destroyed, and harvest damage reached $ 80000. The Tsunami reached maximum heights above the high water level at Kushi-m ura, the Okinawa Island, of about 3. 5 m (p. m. 6h 20-30m). The tide gauge of Taira, Mi-yako Island recorded he oscillation of water level during the Tsunami. It reached the maximum height of 3. 48 m above the average sea level at 6h 51m. The average per iodat the Okinawa and Miyako Islands was about 39 minutes. The Tsunami traveled no r-thwestward to Okinawa with an average speed of 720 km an hour and an average wa velength of about 468 km. Around Okinawa the speed decreased down to about 115 k man hour. The heights and intensities of the waves at different points were influenced by (1) shore-line configuration, (2) offshore submarine topography, (3) presence or absence of coral reefs, (4) the size of the bay, (5) direction of the axis of the bay, (6) position on the island toward or away from the source of the waves, though (5) and and (6) seem to be not so much important as in the Tsunami from a near source, i. e. the Tsunami attached the shores of Sanriku, northeast Japan in 1933 and 1952, and of the Hawaian Islands in 1946.続きを見る
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