Abstract
The field experiments were conducted to investigate the characteristics of sediment movements during a short time duration. The focusing area is from the swash zone to the offshore side of the bar. At the Hasaki coast, Japan, five colored fluorescent sand tracers were installed on the seabed at different cross-shore locations, around every 50 m, from near the shoreline to the offshore side of the bar. During the experiments, seven times of seabed surface sediment samplings were conducted every 10 m of cross-shore distance from 1 hour to 144 hours after the installation of the fluorescent sand tracers. From the analysis, the sediments in the surf zone were spread in the area from near the shoreline to the onshore side of the bar within one hour after the installation. The fluctuation of the centroid of the fluorescent sand distribution was correlated with that of the wave breaking point. The sediment movements at the offshore side of the bar had a correlation with the value of the offshore wave energy flux.
