Study on movement of coral fragments and coral sand in the Okinotorishima Island

This study examined movement of coral fragments and coral sand in the Okinotorishima islands in case of high-energy wave. Wave and current around the island were estimated by the modified Boussinesq equation. Movement of coral fragments and coral sand were calculated by using the formula of saltation for gravel and sand, and instantaneous velocity calculated by the former model. The extent of coral fragments transportation and the amount of sand transportation were made clear. Calculations were carried out in case of four wave directions such as north, south, east and west.