火山性微動の出現様式

Abstract

An equipment was deviced for the purpose of measuring the kinetic energy of the volcanic micro-tremors. The data obtained by this equipment for three years of 1971 to 1973 were analyzed fromthe point of view of the correlation between the emergence of micro-tremors and the rainfall, theseismic activity or the volcanic activity. The rainfall has a great influence on the emergence ofmicro-tremors. In case the rainfall is plentiful, the kinetic energy of micro-tremors, in most cases, is increasing. The earthquakes in and near Aso Caldera have an effect on the micro-tremors, butthe earthquakes far from the Volcano Aso seem to have no relation to the micro-tremors. As regardsthe volcanic activity, the kinetic energy of micro-tremors maintains a high level when the volcanicashes are ejected together with the volcanic gases and the water vapour from the crater.