Earthquake Under the Northern Ibaraki Prefecture on March 24

On March 24, 2023 at 16:25 (JST), there was an M4.7 earthquake (maximum seismic intensity 4) at a depth of 83 km under the northern Ibaraki prefecture. This event occurred within the Pacific plate. The focal mechanism had a tension axis in an NW-SE direction.
For the seismic activity since October 1997, in the vicinity of the recent event (Area b), there have rarely been earthquakes of M4.0 or over. On January 28, 2013, there was an M4.8 earthquake (maximum seismic intensity 5 Lower) and on June 17, 2019, there was an M5.1 earthquake (maximum seismic intensity 4).
For the seismic activity since 1919, in the region around the recent event (Area c), there have sometimes been earthquakes of M5.0 or over. Among them, an M6.5 earthquake (maximum seismic intensity 5) that occurred on June 1, 1930 caused damage with a landslide and so on (Materials for Comprehensive List of Destructive Earthquakes in Japan).

Japan Meteorological Agency
[Evaluation of Seismic Activities for March 2023 (April 11, 2023)]