Earthquake Offshore West of Bonin Islands on May 27

On May 27, 2012 at 06:48 (JST), there was a M6.3 earthquake (maximum seismic intensity 2) at a depth of 499 km, offshore west of Bonin Islands. The focal mechanism (CMT solution) had a compression axis in an NW-SE direction. This event occurred within the Pacific plate.
For the seismic activity since October 1997, in the vicinity of this event (Area b), there have sometimes been earthquakes of M6.0 or over.

For the seismic activity since January 1923, in the area around this event (Area c), there was a M7.6 earthquake on March 6, 1984, which caused damage with a fatality and an injured person (Comprehensive Bibliography of Destructive Earthquakes in Japan, Latest Edition).

Japan Meteorological Agency
[Evaluation of Seismic Activities for May 2012 (June 11, 2012)]