Tsunami alerts issued for northern Japan after powerful quake
A powerful earthquake of magnitude 7.4 to 7.7 struck off northern Japan’s Iwate Prefecture coast on April 20, 2026, prompting tsunami alerts for the region. The Japan Meteorological Agency warned of potential waves up to 3 meters in Iwate, Aomori, and Hokkaido, leading to evacuations.
The quake hit around 4:53-5:53 PM local time at a shallow depth of 10-20 km, with tremors felt as far as Tokyo. An 80 cm tsunami wave was observed about 40 minutes later at a port in Kuji, Iwate, but no larger waves materialized, and alerts were downgraded to advisories before being lifted.
This image shows a TV broadcast of the tsunami warning, displaying quake data, wave heights, and affected coastal maps from northern Japan.
Current Status
No immediate casualties or major damage were reported as of April 21, though bullet trains halted and highways closed temporarily. Authorities formed a crisis team, and Prime Minister Sanae Takaichi urged preparedness.
Ongoing Risks
The JMA raised the chance of a magnitude 8+ mega-quake in the northern Japan Trench to about 1% within the next week, higher than the usual 0.1%. Officials warn of possible aftershocks and further waves in the coming days.
