Major Earthquake Strikes Off Northeastern Japan

A magnitude 7.5 earthquake struck off the northeastern coast of Japan on Monday, April 20, 2026, prompting tsunami warnings, evacuation orders for tens of thousands, and the suspension of transportation services. No immediate reports of significant damage or injuries were confirmed.

Authorities continue to assess the situation and monitor for aftershocks.

Event Details

The Japan Meteorological Agency (JMA) reported the earthquake occurred off the coast of Sanriku in northern Japan at approximately 4:53 p.m. local time (0753 GMT).

• Magnitude: 7.5 (revised from an initial report of 7.4). The U.S. Geological Survey recorded it as 7.4.
• Epicenter: In the Pacific Ocean at a depth of about 10 kilometers (6 miles).
• Intensity: The tremor was felt in Tokyo, hundreds of kilometers away, and registered an upper-5 on Japan's 7-point seismic intensity scale.

Tsunami Warnings and Observations

The JMA issued tsunami warnings and advisories for coastal regions following the earthquake.

Warnings: A tsunami warning for waves as high as 3 meters (10 feet) was issued for Iwate, Aomori, and Hokkaido prefectures.

Advisories: A milder tsunami advisory for waves up to 1 meter was issued for the coasts of Miyagi and Fukushima prefectures.

The JMA advised residents to "evacuate immediately from coastal regions and riverside areas to a safer place such as high ground or an evacuation building," warning that tsunami waves could hit repeatedly.

Observed Waves: Initial tsunami waves observed were below the warning levels. Measurements included:

• Approximately 80 centimeters (2.6 feet) at Kuji port in Iwate prefecture.
• 70 centimeters reported by the JMA.
• 40 centimeters (1.3 feet) at Miyako port in Iwate prefecture.

Government Response and Impact

Prime Minister Sanae Takaichi stated the government established an emergency task force. Chief Cabinet Secretary Minoru Kihara said the situation is still being assessed.

Evacuations: Japan's disaster management agency issued evacuation orders to 171,957 people across five prefectures.

Transport Disruptions:

• Bullet train services in Aomori prefecture were halted.
• Bullet train service between Tokyo and Shin-Aomori station was suspended due to a power outage.
• Train services were suspended between Akita Station and Morioka Station.
• All local trains in Iwate prefecture halted services.

Power and Infrastructure:

• Approximately 200 power outages were reported across impacted areas.
• Tohoku Electric Power Co. and Hokkaido Electric Power Co. reported checking the impact on nuclear plants in the region, including the Onagawa plant. Workers were evacuated from nuclear facilities as a precaution.
• Tokyo Electric Power Company stated no abnormalities were detected at its Fukushima Daiichi, Fukushima Daini, Onagawa, or Higashidori nuclear power plants, and that radioactive material levels were within normal range.

Public broadcaster NHK broadcast live footage of coastlines and repeatedly aired evacuation warnings.

International Impact and Scientific Context

Australia's Bureau of Meteorology stated there is no tsunami threat to Australia.

The JMA warned that aftershocks of similar magnitude could occur in the coming week. Prime Minister Takaichi also warned of potential further advisories due to possible aftershocks.

Japan is located on the Ring of Fire, an area known for intense seismic and volcanic activity.

Historical Context

The affected region was devastated by a magnitude 9.0 earthquake and tsunami on March 11, 2011. That event caused widespread destruction, resulted in over 20,000 deaths, and triggered a nuclear disaster at the Fukushima Daiichi power plant.