Fig. 12

Variations of the magnitude (\(M_{BA}\)) (upper graph) and duration (lower graph) estimated from observed data in relation to elapsed time from the origin for three large earthquakes around the Japanese Islands ( the 2011 Tohoku earthquake \(M_w 9.1\); the 2003 Tokachi-oki earthquake \(M_w 8.3\); the largest aftershock of the 2011 Tohoku earthquake \(M_w 7.9\)). On the magnitude graphs, the horizontal lines indicate \(M_w\) and dashed lines \(M_w\) ±standard deviation of estimated station magnitudes