TOKYO: An earthquake with a magnitude of 6.9 hit northern Japan on Tuesday (Nov 22), generating a tsunami that hit the nation's northern Pacific coast.
The US Geological Survey initially put the quake at a magnitude of 7.3 but downgraded it to 6.9. The Japan Meteorological Agency (JMA) put the earthquake at 7.4-magnitude.
The earthquake, which was felt in Tokyo, was centred off the coast of Fukushima prefecture at a depth of about 10km and struck at 5.59am (4.59am Singapore time), the agency said.
A 60cm tsunami had been observed at Fukushima's Onahama Port and a 90cm tsunami at Soma soon after, public broadcaster NHK said. The region is the same that was devastated by a tsunami following a massive earthquake in 2011. A tsunami measuring 1.4m was also reported at Sendai Port in Miyagi.
A tsunami warning of up to 3m was issued. An announcer on NHK urged residents along the coast to move to high ground. "Please flee immediately," the male voice said with urgency. The vast majority of deaths in the 2011 disaster resulted from the tsunami, and NHK told viewers to heed the lessons of that day.
At around 10am, JMA downgraded its tsunami warnings for Miyagi and Fukushima prefecture.
Japan's Meteorological Agency official Koji Nakamura gives a briefing following a 6.9-magnitude earthquake that hit the country's northeast, in Tokyo on Nov 22, 2016. (Photo: JIJI PRESS/AFP)
East Japan Railway Company suspended its Shinkansen bullet train services on the Tohoku, Joetsu and Hokuriku lines, said NHK.
One woman suffered cuts to her head from falling dishes, Kyodo news agency reported, citing fire department officials.
All nuclear plants on the coast threatened by the tsunami are shut down in the wake of the March 2011 disaster, which knocked out Tokyo Electric Power Co's Fukushima Daiichi nuclear plant, spilling radiation into the air and sea.
A spokeswoman for Tokyo Electric Power, known as Tepco, said the cooling system for a storage pool for spent nuclear fuel at reactor at its Fukushima Daini Plant had been halted, but a spokesman said the cooling system had restarted soon after. The temporary stoppage was an automatic response, according to Tepco.
No other damage from the quake has been confirmed at any of its power plants, although there have been blackouts in some areas, the spokeswoman added.
Only two reactors are operating in Japan, both in the southwest of the country. Even when in shutdown, nuclear plants need cooling systems operating to keep spent fuel cool.
Tohoku Electric Power Co said there was no damage to its Onagawa nuclear plant, while the Kyodo news agency reported there was no irregularities at the Tokai Daini nuclear plant in Ibaraki Prefecture.
Television footage showed ships moving out to sea from Fukushima harbours as tsunami warning signals wailed.
"FAIRLY STRONG EARTHQUAKE"
Earthquakes are common in Japan, one of the world's most seismically active areas. Japan accounts for about 20 per cent of the world's earthquakes of magnitude 6 or greater.
The Mar 11, 2011 quake was magnitude 9, the strongest quake in Japan on record. The massive tsunami it triggered left more than 18,000 people dead or missing, and caused the world's worst nuclear crisis since Chernobyl a quarter of a century earlier.
In April, two strong earthquakes hit southern Japan's Kumamoto prefecture followed by more than 1,700 aftershocks, leaving at least 50 dead and causing widespread damage.
An Iwaki city fire department official said there was smoke or fire at Kureha's research centre in a petrochemical complex in Iwaki city at 6.17am, but it was extinguished at 6.40am. "It was a fairly strong earthquake, but we have not received any reports of injuries," said Nobuyuki Midorikawa, an official in Iwaki city, south of the Fukushima Daiichi plant.
One hotel in Ofunato, badly hit by the 2011 quake, told guests to stay in the facility, which is on high ground.
Speaking during a visit to Argentina, Prime Minister Shinzo Abe directed the central government to work with authorities in the affected areas.
He said he ordered his cabinet ministers to "assess damage and do their utmost to cope with the disaster".
Chief Cabinet Secretary Yoshihide Suga told a press conference in Tokyo that no significant harm had been detected at the nuclear plants in the region.
"There has been no major damage to the Fukushima Daiichi or Onagawa plant (in Miyagi prefecture," he said.