Features of the diurnal periodicity of earthquakes in Japan

The features of the diurnal periodicity of earthquakes with different energies in Japan are studied. The spatiotemporal parameters of different earthquake sets are investigated in detail using various techniques including analyses of amplitudes, dispersion, spectra and correlation. The phases of seismic flows are studied using the modified Rayleigh-Schuster method. Lomb-Scargle periodograms are used to study the frequency of variations in seismicity. The parameters of the sets of earthquakes having different energies obtained in this study indicate changes in phase of the diurnal periodicity of earthquakes to the opposite near the magnitude of completeness. The very clear midday effect is noted.