Authorities warn of waves up to 3 meters as residents evacuate coastal areas
Category: Science
A powerful earthquake measuring 7.5 on the Richter scale struck off the northeastern coast of Japan on April 20, 2026, prompting tsunami warnings across Iwate and Aomori Prefectures and Hokkaido. The quake occurred at approximately 4:53 p.m. local time, with its epicenter located about 100 kilometers off the coast of Iwate Prefecture and at a depth of 10 kilometers, according to the Japan Meteorological Agency (JMA).
The seismic event was strong enough to register a maximum intensity of upper 5 on Japan's seismic scale in parts of Aomori, Iwate, and Miyagi prefectures, and buildings swayed as far away as Tokyo. Reports indicate that the tremors were felt in various locations, including Hashikamizo in Aomori, Miyako, and Morioka in Iwate, as well as Hachinohe and Shichinohe in Aomori.
In the aftermath of the earthquake, the JMA issued a tsunami warning forecasting waves of up to 3 meters along the southern coasts of Iwate and Hokkaido. As of the latest updates, tsunami waves measuring 80 centimeters were observed at Kuji Port in Iwate, with additional waves of 40 centimeters recorded at Miyako Port. Aomori’s Hachinohe Port reported a tsunami of 30 centimeters, and a 20-centimeter wave was observed in the town of Erimo in Hokkaido. Authorities have warned that these waves could come in multiple surges rather than a single impact, creating a potentially dangerous situation for coastal residents.
Prime Minister Sanae Takaichi addressed the situation, urging residents in vulnerable areas to evacuate to higher ground. “Possible damage and casualties are now being looked into,” she said during a press conference. The government has set up an emergency task force to coordinate disaster response efforts.
Evacuation orders have been issued for thousands of residents in coastal areas, particularly in port towns that were severely affected during the 2011 Great East Japan Earthquake and tsunami. Local governments in Iwate, Aomori, Miyagi, and Fukushima prefectures have opened evacuation centers and are providing assistance to those displaced by the tsunami threat.
As part of the precautionary measures, the Tohoku Shinkansen Line and the Akita Shinkansen Line have suspended services between Tokyo and Shin-Aomori. The Japanese government is closely monitoring the situation, with officials emphasizing the importance of remaining vigilant in light of the potential for aftershocks and additional seismic activity over the coming days.
The JMA has also observed a level 3 of long-period ground motion in Akita Prefecture, indicating a strong shake that can make it difficult for people to remain standing and can cause unsecured furniture to topple over. Authorities have emphasized that the evacuation orders should be treated as urgent, with residents advised to stay away from shorelines and river mouths.
In terms of infrastructure, no abnormalities have been reported at the Fukushima Daiichi and Daini nuclear power plants, as well as the Onagawa nuclear power plant in Miyagi Prefecture, according to Tokyo Electric Power Company Holdings. The company confirmed that safety protocols are in place and that there is no immediate threat to nuclear facilities.
Historically, Japan is one of the most seismically active countries in the world, situated on the Pacific “Ring of Fire.” The nation experiences thousands of earthquakes each year, with varying levels of intensity. The events of March 11, 2011, remain fresh in the memory of many, as that earthquake and the subsequent tsunami led to nearly 20,000 deaths and massive evacuations.
As the situation continues to develop, local authorities are assessing the impact of the earthquake and tsunami warnings. They are working to provide timely updates to residents and ensuring that emergency services are prepared to respond to any incidents that may arise.
In the coming days, residents are advised to remain alert and heed the warnings from local authorities and the JMA. The situation remains fluid, and updates will be provided as more information becomes available.
This article is based on reports from multiple sources, including the Japan Times, NHK, and other local news outlets, as well as live updates from the Japan Meteorological Agency.