Direction of Approach of Microseisms Observed in Kyushu

Direction of Approach of microseismic waves was investigated in Kyushu by means of vector seismographs. It was found that no microseismic wave comes from the west direction even when typhoons were situated in the south-west direction. The frequency of arrival directions was distributed partially for the direction of the Hyuga Sea where the continental margin is near to the coast.From these distributions and those at the Abuyama Observatory, it is reasonably concluded that the nearer the continental margin is to the coast, the more frequently microseismic waves are generated.