After Japan issued first official earthquake warning, tremors prompt 90,000 people to take shelter

A powerful 7.5-magnitude earthquake struck north-eastern Japan, injuring over 20 people and prompting mass evacuations along the Pacific coast following the issuance of tsunami warnings.

The earthquake, centred 50 miles (80km) off the coast of Aomori prefecture, registered as an “upper six” on Japan’s seven-point seismic intensity scale—a level strong enough to make it impossible for people to stand without crawling, according to the Japan Meteorological Society (JMS).

The tremors quickly triggered tsunami warnings for the prefectures of Hokkaido, Aomori, and Iwate, leading authorities to order approximately 90,000 residents to evacuate their homes.

Coastal impact and injuries

While the initial warnings were later downgraded to advisories, tsunamis ranging from 20 to 70cm (7 to 27in) were observed at several ports. The largest wave, 70cm, was measured at Kuji port in Iwate.

The Fire and Disaster Management Agency confirmed 23 people were injured, with one person in serious condition. Public broadcaster NHK reported that most victims were hit by falling objects. Incidents included several injuries at a hotel in Hachinohe and a man in Tohoku who was hurt after his car fell into a hole.

Satoshi Kato, a vice-principal at a high school in Hachinohe, described the scene inside his home to NHK, Japan’s national public broadcaster saying “glasses and bowls fell and smashed into shards on the floor.”

Kato also noted that on his way to the school, which was designated an evacuation center, he encountered “traffic jams and car accidents as panicked people tried to flee.”

In response to the emergency, Defense Minister Shinjirō Koizumi confirmed that 18 defense helicopters had been mobilised for a full damage assessment. Roughly 480 residents took shelter at the Hachinohe airbase. Furthermore, NHK reported that about 200 passengers were stranded overnight at New Chitose airport in Hokkaido due to the disruption.

East Japan Railway suspended some services in the region, which is particularly sensitive as it was also severely impacted by the devastating 9.0-magnitude earthquake in March 2011.

Utility companies, including Tohoku Electric Power and Hokkaido Electric Power, confirmed that no irregularities were reported at regional nuclear power plants. However, Tohoku Electric reported that thousands of customers were left without power following the powerful tremor.

Sitting right on the “Ring of Fire,” Japan alone sees about 20% of all earthquakes worldwide that hit magnitude 6.0 or higher.