Magnitude 7.5 earthquake in north Japan injures 23 people

A powerful 7.5-magnitude earthquake shook northeastern Japan late on Monday, injuring more than 20 people and triggering tsunami warnings that, hours later, were downgraded to advisories.

The Japan Meteorological Agency (JMA) initially said a tsunami as high as 3 metres (10 feet) could hit Japan’s northeastern coast after the earthquake struck off the coast at 11:15pm (14:15 GMT) on Monday.

Tsunami warnings were issued for the prefectures of Hokkaido, Aomori and Iwate, and tsunamis from 20 to 70cm (7 to 27 inches) high were observed at several ports, the JMA said.

The epicentre of the quake was 80km (50 miles) off the coast of Aomori prefecture, at a depth of 50km (30 miles), according to the JMA.

In the early hours of Tuesday, the JMA downgraded the warnings to advisories, meaning it now sees lower estimated wave heights and less risk of inundation.

The Fire and Disaster Management Agency said 23 people were injured following the quake, including one seriously. Most of the victims were hit by falling objects, public broadcaster NHK reported, adding that several people were injured in a hotel in Hachinohe, and a man in Tohoku was slightly hurt when his car fell into a hole.

The Pacific Tsunami Warning Center had said that “hazardous tsunami waves from Hokkaido earthquake are possible within 1,000km (620 miles) of the epicentre along the coasts of Japan and Russia”.

Prime Minister Sanae Takaichi had urged residents in affected areas to act quickly.

“Where a tsunami warning has been issued, please evacuate immediately to safe locations, such as high ground or evacuation buildings,” she said in a post on social media.

Chief Cabinet Secretary Minoru Kihara urged residents to seek shelter or higher ground until advisories were lifted.

He said about 800 homes were without electricity, while about 480 residents were taking shelter at the Hachinohe airbase.

Minister of Defence Shinjiro Koizumi said that 18 defence helicopters were mobilised for a damage assessment.

A further 200 passengers were stranded for the night at New Chitose airport in Hokkaido, NHK reported.

East Japan Railway said it had suspended some train services in the region. NHK reported that nuclear power plants in the affected areas were carrying out safety checks, with no immediate signs of problems.

The International Atomic Energy Agency (IAEA) said it had observed no abnormalities at the Fukushima nuclear power plant.

Japan is one of the world’s most earthquake-prone countries, located in the seismically active Ring of Fire.

It accounts for about 20 percent of the world’s earthquakes of magnitude 6.0 or greater, and was hit by a devastating 9.0-magnitude quake and tsunami in March 2011.