Earthquake Off-shore West of Bonin Islands on January 13

On January 13, 2011 at 06:32 (JST), there was a M6.3 earthquake (maximum seismic intensity 2) at a depth of 516km, off-shore west of Bonin Islands. The focal mechanism (CMT solution) had a compression axis in a direction of the subducting Pacific plate. This event occurred within the Pacific plate.
For the seismic activity since October 1997, the area near this event (Area b) is a region with strong seismicity, and there have sometimes been earthquakes of M6.0 or over.

For the seismic activity since August 1923, in the area near this event (Area c), there was a M7.6 earthquake (maximum seismic intensity 4) 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
[Seismic Activity for January 2011 (February 9, 2011)]