부산대학교 도서관

Current observations were carried out in the coral reef lying between two islands, Izena Island and Yanaha Island, in Okinawa Prefecture. The characteristics of the currents in the reef are summerized as follows; 1) Semi-diurnal tidal currents are predominant which are caused by the gradient of the sea surface between the east end and the west end of the reef. The gradient is induced by the phase difference of tide between both ends. 2) The strength of currents responds to the incidental wave height. 3) They also respond to the sea surface elevation. As the sea level rises, the velocity tends to increase.