2022 Volume 78 Issue 2 Pages I_841-I_846
A number of studies have investigated the physical mechanisms of the formation of coral cays through field surveys, laboratory experiments and numerical analysis. These studies show that coral gravels can be naturally accumulated and form coral cays under certain conditions while such natural conditions are limited. To enhance accumulation of coral gravels, authors proposed a gravel trap and showed its effective performance through laboratory experiments.
This study conducted a field survey to test the performance of the gravel trap in the actual field. The trap was placed around Ballast island located in the north of Iriomote Island, Okinawa. Through the field survey, it was found that the trap with modified layout can effectively accumulate coral gravels transported from various directions. Dominant direction of gravel transport, inferred from accumulated gravels around the trap, reasonably agree with the estimated dominant wave direction around the trap.