A magnitude 7.5 earthquake struck off northern Japan late Monday, injuring 23 people and sending a small tsunami onto Pacific coast communities, officials said. The temblor occurred about 11:15 p.m. roughly 80 km (50 miles) off the coast of Aomori prefecture on Honshu, and was centered about 50 km (30 miles) beneath the sea.
Authorities revised the magnitude from an initial 7.6 to 7.5 and initially warned of surges up to 3 meters in some areas before downgrading to advisories. The Japan Meteorological Agency recorded a tsunami of about 70 cm (2 ft 4 in) at Kuji port in Iwate prefecture and roughly 50 cm in other nearby coastal towns. By 6:20 a.m. Tuesday, all tsunami advisories for the Pacific coast in northern Japan had been lifted.
The Fire and Disaster Management Agency reported 23 injuries, including one serious case. Most injuries were caused by falling objects; NHK said several people were hurt at a Hachinohe hotel and one man was slightly injured after his car fell into a hole in Tohoku. Convenience store owner Nobuo Yamada in Hachinohe told NHK he had never experienced such strong shaking, though power lines remained functioning in his area.
Chief Cabinet Secretary Minoru Kihara urged residents to move to higher ground or seek shelter while advisories remained in effect. He said about 800 homes lost power, and that Shinkansen bullet trains and some local rail services were suspended in parts of the region. Prime Minister Sanae Takaichi said the government set up an emergency task force to assess damage and prioritize public safety.
Nuclear facilities carried out inspections after the quake. The Nuclear Regulation Authority reported about 450 liters (118 gallons) of water spilled from a spent fuel cooling area at the Rokkasho reprocessing plant in Aomori but said there was no safety concern and levels remained normal.
About 480 people sought refuge at Hachinohe Air Base, and Defense Minister Shinjiro Koizumi said 18 defense helicopters were deployed to survey damage. Roughly 200 passengers were stranded overnight at New Chitose Airport in Hokkaido, NHK reported.
The meteorological agency warned of possible aftershocks in the coming days and said the chance of a magnitude-8-level quake and a larger tsunami had slightly increased along parts of Japan’s northeastern coast from Chiba to Hokkaido. It urged residents in 182 municipalities to review emergency plans for the week ahead.
Satoshi Kato, vice principal of a public high school in Hachinohe, said he saw glassware and bowls shatter at home and drove to the school designated as an evacuation center, encountering traffic jams and accidents as people fled; no evacuees had arrived at the school at the time.
The quake’s epicenter was near the region devastated by the magnitude 9.0 quake and tsunami in 2011 that killed nearly 20,000 people and damaged the Fukushima Daiichi plant. Officials reminded residents to prepare as if a major disaster could recur.
The U.S. Geological Survey reported another quake early Tuesday, magnitude 5.1, about 122 km (76 miles) south of Honcho at a depth of 35 km. Japanese authorities continued monitoring conditions and conducting damage assessments.
