Earthquake Under the Bungosuido Strait on June 1 (Seismic Activity Since April 17)

On June 1, 2024 at 04:02, there was an M4.5 earthquake (maximum intensity 4) under the Bungosuido Strait at a depth of 39 km. This earthquake occurred within the Philippine Sea Plate. The focal mechanism of the earthquake had a tension axis in an E-W direction. In the vicinity of the hypocenter of the recent earthquake, seismic activity became higher after the M6.6 earthquake (maximum seismic intensity 6 Lower) on April 17, with 82 earthquakes of seismic intensity 1 or over (maximum seismic intensity: number of earthquakes, 6 Lower: 1, 4: 2, 3: 4, 2: 16, 1: 59) occurring from 23:00 on April 17 to 24:00 on June 30. Although the number of earthquakes has decreased, seismic activity continues.
For the seismic activity since October 1997, earthquakes of M5.0 or over have sometimes occurred in the vicinity of the hypocenter of the recent earthquake (Area b).
For the seismic activity since 1919, earthquakes of M6.0 or over have sometimes occurred in the area (Area c) around the epicenter of the recent earthquake: On August 6, 1968, an M6.6 earthquake (maximum seismic intensity 5) caused 22 injuries, mainly in Ehime Prefecture, and 170 kl of heavy oil spilled into the sea in Uwajima due to a pipe break in a heavy oil tank (damage according to the "Materials for Comprehensive List of Destructive Earthquakes in Japan"). Also, the Geiyo Earthquake in 2001 killed two people, injured 288, and destroyed 70 houses (according to the Fire and Disaster Management Agency, Ministry of Internal Affairs and Communications, FDMA).

Japan Meteorological Agency
[Evaluation of Seismic Activities for June 2024 (July 9, 2024)]