A STUDY ON A GENERATION OF SIMULATED EARTHQUAKE GROUND MOTION CONSIDERING PHASE DIFFERENCE CHARACTERISTICS : Part 2 Consideration of the relationship between phase difference distribution and source, propagation, site characteristics

Abstract

It is shown that the wave propagation can be explained on the basis of the simple equation, which expresses the relationship between the phase differences and the delay time of a wave. Since the phase differences of a pulse are uniform, the rupture process of a source region and the wave propagation, including directivity, of an earthquake can be understood in terms of the dispersion with respect to the phase differences of pulses radiated from a sequence of point sources in a fault plane considering the onset time, the location of each point and the dispersion of the apparent phase velocity. This idea is verified by analyzing recorded earthquake motions. It is concluded that the source and propagation characteristics of earthquakes are reflected in the information of phase characteristics.