Magnitude 7.6 earthquake off Aomori, Japan; tsunami warning
Why in the news
A strong undersea earthquake hit the Pacific coast of northern Japan on 8 December 2025, prompting a tsunami warning for coastal areas between Aomori and Iwate.
Key facts
- Magnitude: Mw 7.6 as per USGS; the Japan Meteorological Agency (JMA) gave 7.5.
- Location: Pacific Ocean off Aomori Prefecture, in the Sanriku region.
- Depth: about 40.7 km in the Wikipedia account; an early report said just over 53 km.
- Shaking: maximum shindo intensity of upper 6 in Hachinohe.
- Tsunami: JMA warned of waves up to three metres; the largest observed was 70 cm at Kuji in Iwate.
- Casualties: 47 injuries were reported later and no deaths.
| Parameter | Value |
|---|---|
| USGS magnitude | Mw 7.6 |
| JMA magnitude | 7.5 |
| Depth | About 40.7 km |
| Max tsunami | 70 cm at Kuji, Iwate |
| Injuries | 47 |
About Japan’s seismic setting
- Japan sits where the Pacific, Philippine Sea, Eurasian and North American plates meet, within the Pacific Ring of Fire.
- This quake was a thrust event at a convergent boundary where the Pacific plate sinks beneath the Okhotsk microplate.
- The same region saw the 2011 Tohoku earthquake of magnitude 9.1.
Exam angle
- Disaster items are asked as location plus magnitude: Aomori, Japan, 7.6.
- Know the Ring of Fire and the four plates around Japan.
- Distinguish the agencies: USGS (US) and JMA (Japan).