June 27, 2026
Earthquake Research Committee,
Headquarters for Earthquake Research Promotion
* On June 26, at 22:28, a magnitude (M) 5.6 (provisional) earthquake occurred in eastern Yamanashi Prefecture and the Fuji Five Lakes at a depth of approximately 20 km. The earthquake recorded a maximum seismic intensity 6 Lower in Yamanashi Prefecture. It caused damage and injuries.
* The focal mechanism involved reverse faulting, with the pressure axis oriented in the NW-SE direction.
* GNSS observations revealed no significant crustal deformation related to this earthquake.
* As of 12:00 on June 27, 5 earthquakes with maximum seismic intensity 1 or greater have been recorded, and the seismic activity continues.
* Earthquakes with M4.0 or greater have often occurred near the seismic activity zone. For example, the M6.0 event on August 8, 1983. Furthermore, there have been instances in the past where M4-M5 earthquakes have successively occurred. For example, on January 28, 2012, at 07:39, an M4.9 earthquake (maximum seismic intensity 4) occurred, followed immediately by an M5.4 earthquake (maximum seismic intensity 5 Lower) at 07:43 on the same day. Moreover, on December 3, 2021, an M4.1 earthquake (maximum seismic intensity 4) occurred at 02:17, followed immediately by an M4.8 earthquake (maximum seismic intensity 5 Lower) at 06:37 on the same day.
* This seismic activity is thought to be caused by the collision of the Philippine Sea Plate with the continental plate.
* Based on past general trends, there is a 10-20 percent chance of an earthquake of a similar magnitude occurring following a major earthquake. Therefore, in areas that experienced strong shaking, caution is required for about one week due to the possibility of an earthquake with maximum seismic intensity of approximately 6 Lower. Mainly, earthquakes that cause strong shaking often occur within about 2 to 3 days of the initial shock.
Note: GNSS refers to a generic term for satellite positioning systems, including GPS.