Magnitude 7.6 Earthquake off the coast of Aomori Prefecture, Japan.

The Japan Meteorological Agency recorded a Magnitude 7.6 Earthquake at a depth of about 50 km, about 80 km off the east coast of Aomori Prefecture, which lies on the northern tip of Honshū Island, at about 11.15 pm Japan Standard Time (about 2.15 pm GMT) on Monday 8 December 2025. Thirty four people were injured as a result of the event, with some damage to buildings and roads. A tsunami warning was issued in the immediate aftermath of the event, causing about 90 000 people to evacuate from low lying areas, but in the event, no major tsunami occurred.  Power supplies were also disrupted, leaving 2700 homes without power, and rail services were temporarily suspended. A number of aftershocks have followed the initial event.

The approximate location of the 8 December 2025 Aomori Prefecture Earthquake. USGS.

Japan has a complex tectonic situation, with parts of the country on four different tectonic plates. Aomori Prefecture lies on the convergent margin where the Okhotsk Plate is pushed against the Eurasian Plate, with the Pacific Plate being subducted beneath the Okhotsk Plate to the east. This is not a smooth process; the rocks of the two plates constantly stick together, only to break apart again as the pressure builds up, causing Earthquakes in the process.

The movement of the tectonic plates beneath Japan. University of Wisconsin Eau Claire.

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Magnitude 6.3 Earthquake off the coast of Japan.

The Japan Meteorological Agency recorded a Magnitude 6.3 Earthquake at a depth of about 10 km, off the east coast of Aomori Prefecture, on northern Honshū Island, slightly before 2.30 am Japan Standard Time on Monday 21 December 2020 (slightly before 5.30 pm on Sunday 20 December GMT). The event was felt across much of eastern Japan, though there are no reports of any damage or casualties.

 

The approximate location of the 21 December 2020 Aomori Prefecture Earthquake. USGS.

Japan has a complex tectonic situation, with parts of the country on four different tectonic plates. Eastern Honshū area lies on the boundary between the Pacific, Eurasian and Philippine Plates, where the Pacific Plate is passing beneath the Eurasian and Philippine Plates as it is subducted into the Earth. This is not a smooth process; the rocks of the two plates constantly stick together, only to break apart again as the pressure builds up, causing Earthquakes in the process.

 

The movement of the Pacific and Philippine Plates beneath eastern Honshū. Laurent Jolivet/Institut des Sciences de la Terre d'Orléans/Sciences de la Terre et de l'Environnement.

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