A strong earthquake with a preliminary magnitude of 7.4 hit northeastern Japan on Tuesday morning, the Meteorological Agency said, with a tsunami of over 1 meter observed in Miyagi Prefecture and other areas on the Pacific coast.
The quake is an aftershock of the March 2011 earthquake that, along with ensuing tsunami, devastated wide coastal areas in northeastern Japan, the agency said. It is the first quake with a magnitude of 7 or bigger to hit Japan since July 2014.
Some people suffered minor injuries in Fukushima, according to local firefighters.
The agency warned that there may be similar-scale quakes for around a week.
A tsunami measuring 140 centimeters was observed at Sendai port in Miyagi Prefecture at 8:03 a.m., and waves of up to 90 cm were seen in other coastal areas in Fukushima and Ibaraki prefectures, according to the agency.
At 12:50 p.m. all tsunami warnings and advisories were lifted, the agency said.
The agency had warned of further tidal waves of up to 3 meters for Fukushima, where work continues to decommission the Fukushima No. 1 nuclear plant crippled by the 2011 quake and ensuring tsunami, and Miyagi. The agency had also said that 1-meter waves could reach other parts of the coastline facing the Pacific.
A wave of about 1 meter reached the coast where the Fukushima No. 1 complex is located, according to its operator Tokyo Electric Power Company Holdings Inc.
The 5:59 a.m. quake, which also shook the Tokyo area, measured lower 5 on the Japanese seismic intensity scale of 7 in Fukushima, Ibaraki and Tochigi prefectures, the agency said.
It was the first time since December 2012 for the agency to issue a tsunami alert due to an aftershock of the 2011 quake.
The focus of the quake was about 25 kilometers underground in the Pacific Ocean off Fukushima and resulted from a vertical fault movement, a phenomenon prone to trigger tidal waves, the agency said.
A nuclear fuel cooling facility for the Fukushima No. 2 nuclear power plant’s No. 3 reactor building temporarily stopped operating, according to Tepco.
“(We) are currently confirming the situation, but I have been informed that (the cooling failure) will not immediately lead to a radiation leak or an increase in the temperature of the fuel,” Chief Cabinet Secretary Yoshihide Suga told a hastily arranged news conference in Tokyo on Tuesday morning.
Also at the Fukushima No. 2 complex, equipment to measure dust for radioactive materials within the premises of the complex stopped working. Tepco said the fault has not caused any serious problems.
No abnormalities were observed at other nuclear plants in Fukushima and other parts of northeastern Japan, according to Tepco and other power companies. Reactors at these nuclear plants have been offline.
Prime Minister Shinzo Abe said in a news conference in Buenos Aires that the government will assess the damage caused by the quake and provide citizens with necessary information.
Suga said there have not yet been reports of significant damage from the quake or tsunami.
He said the government “will continue to ascertain information about damage, work closely with the Self-Defense Forces and dedicate every effort to disaster response.”
Suga called on those in the affected areas to pay attention to evacuation instructions from the SDF and relevant authorities, to monitor information broadcast on television and radio, and to help those in need.
The Defense Ministry sent SDF fighter aircraft and choppers to quake-hit regions to check for damage.
Rail and flight services were disrupted, with some bullet trains temporarily halted and some flights to and from Sendai airport canceled.
The quake temporarily stopped bullet train services on the Tohoku, Joetsu, Hokuriku and Yamagata Shinkansen lines, East Japan Railway Co. said.
The company also suspended its train services between Sendai and Hitachi to check the safety of tracks near the ocean after tsunami waves were observed.
A total of eight Shinkansen bullet trains were delayed up to 23 minutes on the Tokaido line connecting Tokyo and central and western Japan, affecting some 5,600 passengers, Central Japan Railway Co. said.
Dozens of schools in coastal areas of northeastern Japan called off classes, and hundreds of people evacuated to school gymnasiums and other facilities in Fukushima.
A fire occurred at a petroleum complex in Iwaki at around 6:15 a.m. and was put out about 25 minutes later, according to the Fukushima prefectural police. It was not immediately known if the fire was caused by the quake. There were no reports of injuries from the fire.