A Practical Prediction Methods of Major Earthquakes Using High-frequency Tremor Events

The earthquake prediction, one of the most efficient methods has been tried to develop based on modern scientific method this half century using seismic activity, crustal deformation, chemical anomalies without practical results except only two rare cases with the result of general pessimistic evaluation. The seismic activity has been the field of the most often approached in comparison with other phenomena. Especially foreshocks are investigated enough to provide many useful results but critical defect is unstable occurrence. On the other hands important progress is attained in the laboratory investigation of process of nucleation providing important results. However, those result cannot be confirmed by field observation just before occurrence of major earthquakes. Here we make a special seismic catalog of high frequency tremors deduced anew from continuous seismic data of just before major earthquakes using the extensive network, High-net of Japan. Analyses of catalog for three major and one a little bit smaller earthquakes show that there are three successive precursory phenomena, first at some six weeks, second at some four weeks, and finally immediately before the earthquake. And the three items of prediction, time, location and magnitude can be predicted exactly enough for actual disaster mitigation efforts at each moment of distinguishing of those precursors.