Possible scenarios for occurrence of M ∼ 7 interplate earthquakes prior to and following the 2011 Tohoku-Oki earthquake based on numerical simulation

We show possible scenarios for the occurrence of M similar to 7 interplate earthquakes prior to and following the M similar to 9 earthquake along the Japan Trench, such as the 2011 Tohoku-Oki earthquake. One such M similar to 7 earthquake is so-called the Miyagi-ken-Oki earthquake, for which we conducted numerical simulations of earthquake generation cycles by using realistic three-dimensional (3D) geometry of the subducting Pacific Plate. In a number of scenarios, the time interval between the M similar to 9 earthquake and the subsequent Miyagi-ken-Oki earthquake was equal to or shorter than the average recurrence interval during the later stage of the M similar to 9 earthquake cycle. The scenarios successfully reproduced important characteristics such as the recurrence of M similar to 7 earthquakes, coseismic slip distribution, afterslip distribution, the largest foreshock, and the largest aftershock of the 2011 earthquake. Thus, these results suggest that we should prepare for future M similar to 7 earthquakes in the Miyagi-ken-Oki segment even though this segment recently experienced large coseismic slip in 2011.