Abstract
The free spheroidal oscillations of the earth corresponding to the period range 10.5 to 2.5 minutes have been observed in the spectrum of the seismogram recorded at Matsushiro following the Chilean earthquake of May 22, 1960. The observed periods and the phase velocities of the Rayleigh waves computed thereof have been compared with those obtained from many previous observations and the theoretical values. The attenuation of the oscillation was estimated in order to compute the Q values for a number of spectral peaks, and the possibility of observing short period vibrations was discussed in connection with the commencement time of the analysis.
