Abstract
The purpose of this paper is to discuss the statistical distribution of the largest annual ground motion due to earthquakes. The extreme value distributions at 13 stations which are selected from the seismological stations of JMA (Japan Meteorological Agency) are firstly obtained for the period from 1951 to 1974. Similarly, the distributions of the maximum yearly acceleration at 6 points which are a part of the strong motion seismograph network of Port and Harbour Research Institute, Ministry of Transport, are obtained for the period from 1965 to 1974. These distributions agreed well with Gumbel's extreme value distributions of the second type. Corresponding analytical distributions will be given when the Poisson process and Gutenberg and Richter's law of magnitude are established. In this calculation b values of Gutenberg and Richter's law and average annual rate of earthquake occurrences are estimated from the earthquake catalogue for the period from 1885 to 1974. Analytical distributions of extreme values agreed well with observed ones, which are shown in Fig. 4 and 5.
