The Fifth 5-Year Program for Earthquake Prediction in Japan

The fourth period of the Japanese national program for earthquake prediction will expire in March, 1984. In June of 1983, the fifth 5-year plan for the next period was proposed by the Geodetic Council, Ministry of Education, Japan. Prior to establishment of the new plan the results in the fourth period were critically reviewed. The new plan, as well as the review, is briefly described in this paper. Several precursors have been clearly observed before some earthquakes with magnitudes around 7, but, on the other hand, observations have also revealed a remarkably complicated appearance of precursors. Therefore, earthquake prediction should be based on a synthesis of various observed phenomena. Taking this into account, the new plan put its emphasis on the efforts to increase the accuracy of prediction, though the items of observations are not so different from those in the fourth period.