Japanese government has warned of a slightly heightened risk of a megaquake in the next week after a strong 7.4-magnitude earthquake struck off the country’s northeastern coast on Monday, triggering a tsunami warning, according to the Japan Meteorological Agency and the US Geological Survey.
The three-meter (9.8-foot) tsunami warning was issued following the quake, but the threat was later revised down to a tsunami advisory before being lifted altogether, authorities said.
Now residents in 182 towns across seven prefectures have been urged to be on alert for a potential stronger earthquake and to confirm evacuation routes and shelters, Japan’s national broadcaster NHK reported.
The megaquake advisory is not a prediction, but officials from Japan’s Cabinet Office and the Japan Meteorological Agency said there was a 1% chance of an earthquake of magnitude 8 or stronger striking along two deep sea trenches in the Pacific in the next week, compared to a 0.1% chance during normal times, the Associated Press reported.
A similar advisory was issued following a 7.5-magnitude earthquake that struck off Japan’s northeastern coast in December 2025, but a larger quake did not occur.
Monday’s earthquake prompted the country’s disaster management agency to issue evacuation orders to more than 180,000 people.
Two people were injured after falling, according to Japan’s Fire and Disaster Management Agency, the AP reported. But no damage to homes had been recorded, chief cabinet secretary Minoru Kihara said Monday evening local time, noting the situation was still being assessed.
Kihara added that there were 200 power outages across the impacted areas and authorities were working to restore service.
The Japan Meteorological Agency initially issued a three-meter tsunami warning for the Iwate prefecture and parts of Hokkaido and Aomori, later downgraded to an advisory. It also issued an advisory in other areas of northeastern Japan, estimating a tsunami of up to one meter (3.3 feet).
During a tsunami warning, waves of up to three meters are expected and would cause damage to low-lying areas. A tsunami advisory is the lowest-level alert, and is issued when waves of up to one meter are expected.
At that alert level, the Japan Meteorological Agency warns that anybody exposed will be caught in strong tsunami currents, and it advises people to leave coastal areas immediately.
Bullet train services resumed their operations Monday evening after suspending operations due to power outages caused by the earthquake, NHK reported Tuesday. Affected trains included services between Tokyo and Shin-Aomori stations, Akita and Morioka stations in northern Japan, and local trains in Iwate prefecture, according to NHK.
Tokyo Electric Power Company said in a statement that no abnormalities had been detected at its Fukushima Daiichi and Fukushima Daini nuclear power plants, although it evacuated workers.
The Tohoku Electric Power Company said that its Onagawa nuclear plant and Higashidori nuclear plant further north have also not experienced abnormalities, with radioactive material levels still within normal range.
Japan is one of the most earthquake-prone countries in the world. It lies on the Ring of Fire, an area of intense seismic and volcanic activity on both sides of the Pacific Ocean.
The worst quake in recent Japanese history was the 9.1-magnitude Tohoku earthquake in 2011, which triggered a major tsunami and nuclear disaster.
