July 10, 2026
Earthquake Research Committee,
Headquarters for Earthquake Research Promotion

Evaluation of Earthquake in Eastern Yamanashi Prefecture and the Fuji Five Lakes on June 26, 2026

* On June 26, at 22:28, a magnitude (M) 5.6 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 a reverse fault type, with the pressure axis oriented in the NW-SE direction.

* Following the earthquake, high acceleration values were recorded, including 1,004 gal (three-component composite) at the K-NET Otsuki observation station in Yamanashi Prefecture. Furthermore, at the Nagahama observation station in Fujikawaguchiko Town, Yamanashi Prefecture, where seismic intensity 6 Lower was recorded, shaking with a predominant period of approximately 0.5 seconds is thought to be the result of the characteristics of shallow soil layers near the observation point and is one of the reasons why the seismic intensity was higher than at surrounding observation points.

* GNSS observations revealed no significant crustal deformation related to this earthquake.

* As of June 30, there have been 9 earthquakes with a maximum seismic intensity 1 or greater.

* 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.

* This seismic activity is thought to be caused by the collision of the Philippine Sea Plate with the continental plate.

Note: GNSS refers to a generic term for satellite positioning systems, including GPS.

• Overview
• Seismic Activity
• Seismic Activity (continued)
• Seismic Activity (continued)
• Seismic Intensities and Accelerations
• Seismic Intensities and Accelerations (continued)
• Strong Ground Motions
• Strong Ground Motions (continued)
• Strong Ground Motions (continued)
• Crustal Deformations
• Crustal Deformations (continued)
• Past Seismic Activity
• Past Seismic Activity (continued)
• Hypocenter Distribution
• Hypocenter Distribution (continued)
• Stress Field Around Eastern Yamanashi Prefecture
• Stress Field Around Eastern Yamanashi Prefecture (continued)