Earthquake Offshore East of Hokkaido on May 3

On May 3, 2016 at 09:00 (JST), there was a M5.9 earthquake (maximum seismic intensity 3) offshore east of Hokkaido. The focal mechanism (CMT solution) showed a strike-slip fault type with a compression axis in an NW-SE direction.
For the seismic activity since October 1997, in the vicinity of the recent event (Area a), there have sometimes been earthquakes of M5.0 or over. Recently, there was a M6.3 earthquake (maximum seismic intensity 4) on July 7, 2015. On January 28, 2000, there was a M7.0 earthquake (maximum seismic intensity 4) which caused 2 injured persons (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 M8.0 over or with damage. On October 4, 1994, there was "the 1994 Hokkaido-Toho-Oki Earthquake" (M8.2, maximum seismic intensity 6). The earthquake caused tsunami with a height of 173 cm at Hanasaki, Nemuro City and 97 cm at Kushiro, and was observed from Hokkaido to Okinawa prefectures. It also caused damage with 435 injured parsons, and 4,586 collapsed houses and so on (Comprehensive Bibliography of Destructive Earthquakes in Japan).

Japan Meteorological Agency
[Evaluation of Seismic Activities for April 2016 (May 13, 2016)]