Abstract
It has been generally understood the seismic intensity has a good correlation to the maximum acceleration of seismic ground motions. In the present study, it was found that seismic intensity has a better correlation to the maximum energy of seismic waves rather than to maximum acceleration. The material was taken from the seismic data obtained at the Nagano Weather Station for the Matsushiro swarm earthquakes.
Fig.1 illustrates the relation between the maximum displacement and seismic intensity, which shows a fairly good correlation except for Intensity I. Fig.2 illustrates the relation between the maximum velocity of seismic waves and intensity. In intensities IV and V, the linearity is poor. Fig.3 illustrates the relation between maximum acceleration and intensity. In intensities, I and II, the deviation is large. Accordingly, the logarithm of maximum acceleration and seismic intensity does not have a simple linear relation.
The relation between the maximum energy of seismic waves and seismic intensity is shown in Fig.4, which gives a good linearity all the way from I to V. Fig.5 shows the relation between the total energy of seismic waves and intensity, in which the deviation is large again in I, II and V.
All these results, the author believes, well support the statement made above.
