Aftershock Activities of the 2011 off the Pacific Coast of Tohoku Earthquake

During May 2015, in Area a (the source region of "the 2011 off the Pacific coast of Tohoku Earthquake" and outside of the source region inclusive of the eastern side of the trench axis), there were 3 earthquakes of M5.0 or over. In addition, there were 2 earthquakes with a maximum seismic intensity 4 or over.
Aftershock activities of "the 2011 off the Pacific coast of Tohoku Earthquake" that occurred on March 11, 2011 have gradually been declining as a whole, and the recent changes have become smoother than before, but the aftershock activity, especially near the coastal regions, still remains in brisk state in comparison with the activity before the main shock.
In Area a, following are earthquakes of M5.0 or over in May 2015, respectively.

Japan Meteorological Agency
[Evaluation of Seismic Activities for May 2015 (June 9, 2015)]