Yesterday's earthquake off the coast of Japan was an aftershock of the magnitude 9.0 earthquake that spawned a deadly tsunami in the same region in 2011, the Japan Meteorological Agency said.
The agency warned that another large quake could hit in the next few days and urged residents to remain cautious for about a week.
Yesterday's earthquake brought back memories of the 2011 disaster for many locals.
Kazuhiro Onuki is a former librarian in a town that became a no-go zone after the 2011 quake and tsunami because of radiation contamination. He was staying at what he calls one of his temporary homes when yesterday's magnitude 7.4 earthquake struck.
He said he remembered "3/11", a reference to the March 11 date of the 2011 disaster.
"It really came back. And it was so awful. The sways to the side were huge. But nothing fell from shelves."
Onuki was alone when the latest earthquake struck and worries it could be a warning of things to come.
However, while yesterday's earthquake triggered tsunami warnings, there were no reports of deaths or serious damage.
Several hours after residents along the Fukushima and Tohoku coastlines were told to evacuate to higher ground and remain there, the danger appeared to have passed, and the tsunami warnings were lifted.
The relatively shallow quake struck at 6am (noon NZT) local time and was centred about 25km off the coast from Namie, a town close to the Fukushima Daiichi nuclear plant. The magnitude was revised several times, but the Japan Meteorological Agency stated later that it measured a 7.4. It was followed by large aftershocks measuring 5.4 and 4.8.
There appeared to be no damage or changes in the radiation level at the Daiichi plant, which suffered a triple meltdown after the 2011 earthquake and remains in a highly fragile state. But a cooling system at another shuttered nuclear power plant 10km up the road shut down briefly, sparking fears that the fuel rods inside the reactor could heat up. Tepco later reported that normal operations had been resumed.
Bullet train services were temporarily suspended, and a fire broke out at a petrochemical plant, although it was soon extinguished.
The earthquakes were felt in Tokyo, 260km south of the epicentre.
Prime Minister Shinzo Abe was in Argentina yesterday, following the Apec meeting in Peru, but he said the Government was ready to respond. The enormous 2011 earthquake caused huge damage at the Fukushima nuclear plant and the evacuation of the area around it for fear of radiation. Even today, the villages closest to the plant remain ghost towns, frozen in time.
But it was the tsunami that followed that had the most devastating results. A 15m-high wave inundated the Tohoku region, north of Fukushima, claiming 18,000 lives. Today, 60,000 people still live in temporary housing, and coastal towns such as Rikuzentakata remain huge construction sites, as authorities try to raise the land above the tsunami risk zone.
- Washington Post, AP