Earthquake under the Ocean Area near Amami Oshima on January 9

On January 9, 2016 at 23:12 (JST), there was a M5.4 earthquake (maximum seismic intensity 4) at a depth of 28 km under the ocean area near Amami Oshima. The focal mechanism (CMT solution) showed a reverse fault type with a compression axis in an N-S direction (preliminary).
The seismic activity has become high and there have been 11 aftershocks with maximum seismic intensity 1 or over. Now the aftershock activity is settled.
For the seismic activity since October 1994, in the vicinity of the recent event (Area a), the seismic activity has been brisk and there have often been earthquakes of M4.0 or over. On December 9, 2001, there was a M6.0 earthquake (maximum seismic intensity 5 Upper), which caused damage with 1 partially collapsed house (Fire and Disaster Management Agency).
For the seismic activity since January 1923, in the area around the recent event (Area b), there have sometimes been earthquakes of M6.0 or over. Among them, a M6.1 earthquake (maximum seismic intensity 5) on January 1, 1970 caused damage with 5 injured persons and 1,462 partially collapsed houses and so on (Comprehensive Bibliography of Destructive Earthquakes in Japan)

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