Wave disasters caused by large swells have occurred on the coast of Toyama Wan, and these swells have been studied by many researchers. As a result of the studies, it is known that water level fluctuations with periods of several minutes occur off the coast of the Toyama Wan, when large swells invade the Toyama Wan. But generation mechanism of the water level fluctuations does not become clear.
And so, the generation mechanism was investigated by wave observations off the coast of Toyama Wan and wave generating experiments using water tank. As the results, they became clear that the water level fluctuations with periods of several minutes are proper oscillations in horizontal shallow water off coast, and mean water level in a horizontal shallow water jutting out from a coast rises several meters due to swells invading the horizontal shallow water.
