Figure 7. Spatiotemporal evolution of the hypocenters
(a )–(c ) before and (d)–(f ) after the
mainshock. (a ) Projection of the hypocenters, (d ) map
view, (b ) and (e ) east–west cross section, and
(c ) and (f ) north–south cross section. The symbol
sizes corresponds to the JMA magnitude. The hypocenters are colored
according to their occurrence time measured relative to that of the
mainshock, that is, the mainshock occurred at time 0 and negative and
positive numbers denote the days before and after the mainshock,
respectively.