Fig. 3

a Distribution of hypocenters with an Mj greater than 4.0 within 24 h of the mainshock (Kurahashi and Irikura 2011). b Hypocenter distribution shallower than 700 km (Mj 2.0 to 9.9, duration: March 11, 2011 to March 10, 2012). The earthquake dataset was obtained from the JMA Earthquake catalog. Figure 3 and the subsequent figures are superimposed on the fault distribution map of the NE Japan Arc. The fault symbols are the same as those in Fig. 2