Earthquake under Western Aichi Prefecture on March 4
[Middle Western Mino Region, Gifu Prefecture] was the regional name of the epicenter used in the Japan Meteorological Agency announcement.
On March 4, 2015 at 00:04, there was a M4.6 earthquake (maximum seismic intensity 4) at a depth of 40 km under western Aichi prefecture. This event occurred within the Philippine Sea plate. The focal mechanism of this event showed a strike-slip fault type with a tension axis in an NE-SW direction.
For the seismic activity since October 1997, in the vicinity of the recent event (Area b), there have sometimes been earthquakes of M4.0 or over. On December 24, 2005, there was a M4.8 earthquake (maximum seismic intensity 4), which caused damage with 1 injured person (Fire and Disaster Management Agency).
For the seismic activity since January 1923, in the region around the recent event (Area c), there have sometimes been earthquakes of M5.0 or over. On July 7, 1925, there was a M5.6 earthquake, which caused damage with chimneys and fences collapse (Comprehensive Bibliography of Destructive Earthquakes in Japan).
Japan Meteorological Agency
[Evaluation of Seismic Activities for February 2015 (March 10, 2015)]