Abstract
The seismic coda waves of microearthquakes observed at Matsushiro region, in the early stage of Matsushiro swarm of 1965-1969 are analysed to obtain the character of seismic source and seismic medium at Matsushiro by comparing with observations in Parkfield, California. Aki's method which analyses seismic coda waves as scattered wave is applied.
The magnitude of earthquakes used in this analysis ranges from -0.7 to 3.9.
The short period seismic waves are more dominant at Matsushiro earthquake than at Parkfield. The value of scattering factor is almost the same order in both regions. The seismic moment of magnitude zero earthquake at Matsushiro is obtained as 1017-3 dynes cm.
