Earthquake in the Kumamoto Region, Kumamoto Prefecture on June 8
On June 8, 2021 at 16:59 (JST), there was an M3.9 earthquake (maximum seismic intensity 4) at a depth of 11 km in the Kumamoto region, Kumamoto prefecture. This event occurred within the crust. The focal mechanism showed a strike-slip fault type with a tension axis in an N-S direction.
For the seismic activity since January 2021, in the vicinity of the recent event (Area a), there have sometimes been earthquakes of M4.0 or so, and the maximum seismic intensity 4 is observed three times, including the recent event. Also on June 26, there was an M4.0 earthquake (maximum seismic intensity 3).
In Area a, there were "the 2016 Kumamoto Earthquakes" which caused damage with 273 fatalities in Kumamoto and 3 fatalities in Oita prefectures and so on (as of June 11, 2021 for Kumamoto prefecture (Kumamoto prefecture) and as of April 12, 2019 for other data (Fire and Disaster Management Agency)).
For the seismic activity since 1885, in the region around the recent event (Area b), there have sometimes been earthquakes of M5.0 or over. Of these on July 28, 1889, there was an M6.3 earthquake which caused damage with 19 fatalities, 234 completely collapsed houses and so on in Kumamoto prefecture, centering on Kumamoto City (Materials for Comprehensive List of Destructive Earthquakes in Japan).
Japan Meteorological Agency
[Evaluation of Seismic Activities for June 2021 (July 9, 2021)]