M7.4 quake hits northeastern Japan, tsunami observed
The 5:59 a.m. quake with a preliminary magnitude of 7.4 is believed to be an aftershock of the March 2011 earthquake, the Japan Meteorological Agency said.
It is the first quake with a magnitude of 7 or bigger to hit Japan since July 2014. 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 and a wave of about 1 meter reached the coast near the Fukushima Daiichi nuclear power plant that was crippled by the 2011 quake-tsunami disaster.
Authorities instructed residents in coastal areas to evacuate to higher ground and hundreds of schools canceled classes. Over 3,000 people fled to evacuation centers in Fukushima.
"The sound of sirens brought back memories of the huge earthquake (in 2011)," said Tomomi Nagakubo, 48, who drove in her car to an evacuation center in Ibaraki Prefecture with her 13-year-old son.
A nuclear fuel cooling facility for the Fukushima Daini power plant's No. 3 reactor building temporarily stopped working, according to its operator Tokyo Electric Power Company Holdings Inc.
"We are currently confirming the situation, but I have been informed that it will not immediately lead to a radiation leak or an increase in the temperature of the fuel," the government's top spokesman Yoshihide Suga said in a press conference in Tokyo.
Equipment to measure dust for radioactive materials within the premises of the Fukushima Daini complex also stopped working, but 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 idle.
There are reports of injuries in affected areas, including Fukushima and Miyagi as well as Tokyo, according to local police officers and firefighter departments.
Sixteen small boats were overturned off the coast of Miyagi, the Japan Coastal Guard said, adding no one was believed to be onboard any of them.
The weather agency warned of further tidal waves of up to 3 meters for Fukushima, where work continues to decommission the Fukushima Daiichi complex, and Miyagi. The agency said 1-meter waves could reach other parts of the coastline facing the Pacific, but it later downgraded the warnings to advisories.
The 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 Japan Meteorological Agency said.
It was the first time since December 2012 that the agency had issued a tsunami alert due to an aftershock from the 2011 quake.
The focus of the quake was about 25 kilometers under the seabed in the Pacific Ocean off Fukushima, the agency said. The underwater quake resulted from a vertical fault movement, a phenomenon likely to trigger tidal waves, it said.
Prime Minister Shinzo Abe said in a press conference in Buenos Aires that the government will assess the damage caused by the quake and keep the public informed.
Suga said there have been no reports yet of significant damage from the quake or tsunami. He said the government "will continue to gather information about damage, work closely with the Self-Defense Forces and dedicate every effort to disaster response."
Suga called on people in the affected areas to remain alert to evacuation instructions from the SDF and relevant authorities, pay attention to information broadcast on television and radio and help each other.
The Defense Ministry sent SDF fighter aircraft and choppers to quake-hit regions to check for quake damage.
Rail and flight services were disrupted, with some bullet trains temporarily halted and some flights to and from Sendai airport canceled.
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, but there were no reports of injuries from it.