Japan Hit by 7.4-7.7 Magnitude Earthquake Off Northeastern Coast, Tsunami Warnings Downgraded

A powerful earthquake struck off Japan's northeastern coast on April 20, 2026, with reported magnitudes varying between 7.4 and 7.7 across sources. m. local time, centered in the Pacific Ocean at a depth of about 20 kilometers, approximately 530 kilometers from Tokyo.

It prompted the Japan Meteorological Agency to issue tsunami warnings for coastal areas, anticipating waves up to three meters, though these were downgraded to advisories for swells up to one meter. About 100 homes lost power, and bullet train services were suspended, with some motorways closed.

Tremors were felt as far as Tokyo.

Over 156,000 people were evacuated across five prefectures, with some sources reporting more than 170,000 under evacuation orders. Ships were seen leaving ports like Hachinohe in Hokkaido to avoid potential waves. The government set up an emergency task force and urged residents to evacuate to higher ground.

Prime Minister Sanae Takaichi stated that the government had established the task force and encouraged citizens in affected areas to confirm evacuation routes and prepare emergency supplies. A government spokesperson, Minoru Kihara, noted during a news conference that no major damage occurred.

Officials estimated the probability at 1 percent, ten times higher than the usual 0.1 percent. This advisory applied to 182 municipalities from Hokkaido to Chiba. Residents were advised to take anti-disaster measures and protect their lives. One resident in Hokkaido described local authorities using loudspeakers to warn people and office workers leaving early.

The International Atomic Energy Agency reported no abnormalities at Japan's nuclear facilities following this event. Japan lies in the Ring of Fire, experiencing about 20 percent of the world's earthquakes of magnitude 6 or higher. Tremors occur at least every five minutes in the country.

Tsunami observations included waves of 80 centimeters at Kuji port and 40 centimeters at another Iwate port. The U.S.-based Pacific Tsunami Warning Center later declared the tsunami threat had passed. Nuclear authorities confirmed all facilities in the region remained intact.

This was the second such advisory in recent months, following a 7.5-magnitude quake in December 2025, after which no mega-quake occurred. Officials emphasized the advisory was not a prediction but a call for preparedness.