Fig. 9

Temporal variations and probability density distributions of \(b\) in regions of low \(p\)-values for \(N=50\) and \(l=0.4^\circ\). Horizontal bars indicate the analysis periods (from the first to the \(N\) th earthquake). a Low and b high \(b\)-value regions that may be related to large earthquakes in area A. c Regions of steadily low \(b\)-values in area A. d Regions of steadily high \(b\)-values in area A. e Low and f high \(b\)-value regions in area B. In a and b, the time variation is shown with respect to the elapsed time from the large earthquake that seems to have caused the largest effect on the seismic activity shown in the legends. The left and middle panels show variations before and after the large earthquakes, respectively. Numbers in square brackets in the legend in the right panels indicate the number of estimated index values. The regions correspond to those shown in Fig. 7. The arrows in c show the times when slow slip was detected near region L (off Boso Peninsula). PDDs in right panels in d and e exclude the activities in regions g and R (the Izu islands), respectively