Where do Swells turn into Microseisms?

During the I. G. Y. period, observations of microseisms were made at many stations in Japan. The data obtained at these stations gave the writer important informations about the occurrence of microseismic storms due to the passing of a cyclone or a typhoon around Japan. Microseisms appear to occur at the time when swells due to the meteorological disturbances reach some coast near the station. This conclusion is supported by the comparison of microseismic amplitudes and swells heights at the same station.The period relation between microseisms and swells was also investigated and Spectrum of swells examined. The results strongly supports the “Standing wave theory” of Higgins.All of these results lead us to an conclusion that the swells which are due to a single disturbance source in an Ocean turn into microseismic waves at some steep coast of the land at which standing waves can be generated owing to the interferences of the incident and reflected swells.