Earthquake Clustering in the Kanto District

Earthquakes in the Kanto district (Japan) between January 1983 and March 1987 are analysed for the identification of independent main shocks and for the hierarchical clustering of secondary earthquakes using the statistical clustering and subclustering methods. Using the results of earthquake classification, the characteristics of seismicity in the Kanto district are investigated. It is found that the b values vary for different earthquake classes and in different geographical regions, and the seismic hazard also varies with earthquake classes.