Earthquake in Sanpachi-Kamikita Region, Aomori Prefecture on January 11

On January 11, 2016 at 15:26 (JST), there was a M4.6 earthquake (maximum seismic intensity 5 Lower) at a depth of 10 km in Sanpachi-Kamikita region, Aomori prefecture. This event occurred within the crust. The focal mechanism showed a reverse fault type with a compression axis in an ENE-WSW direction. 7 aftershocks have occurred with seismic intensity 1 or over.
For the seismic activity since October 2002, in the vicinity of the recent event (Area a), the activity was low: such as a M2 or so earthquake per several years, before "the 2011 off the Pacific Coast of Tohoku Earthquake." After that earthquake, the seismic activity has become rather high.
For the seismic activity since January 1923, in the area around the recent event (Area b), there were 4 earthquakes of M5.0 over. On May 16, 1978, there were two M5.8 earthquakes, which caused damage with spalling of mortar walls and destruction of block fences (damage: Comprehensive Bibliography of Destructive Earthquakes in Japan).

Japan Meteorological Agency
[Evaluation of Seismic Activities for January 2016 (February 9, 2016)]