Earthquake - Tsunami - Japan - Commemorated

People in Japan stopped what they were doing Sunday and marked the moment a powerful earthquake struck the country one year ago, with a moment of silence.

Almost 19,000 people were killed in the earthquake and following tsunami. Entire cities and towns were wiped off the land.

More than 340,000 people are still living in temporary housing.

Emperor Akihito led a national memorial service in Tokyo, and smaller memorials were held across the country.

The moment of silence was observed at 2:46 p.m. local time, at the exact moment the 9.0-magnitude earthquake hit last year and unleashed a wall of water that hit Japan's northeast coast.

While much of the debris has been gathered into massive piles, very little rebuilding has begun.

A woman weeps during a moment of silence to pay tribute to those who lost their lives in the March 11, 2011 earthquake and tsunami in Tokyo. (Junji Kurokawa/Associated Press)

"I wish I could go back to my old house and get back our normal life again," said Hyakuaiko Konno, a 64-year-old woman from the Ishinomaki coast who has been living in temporary housing for the past seven months.

The government says the damaged Fukushima Dai-ichi nuclear plant, where three reactor cores melted down after the tsunami knocked out their vital cooling systems, is stable and that radiation coming from the plant has subsided significantly.

However, the plant's chief told journalists visiting the complex recently that it remains in a fragile state, and makeshift equipment — some mended with tape — could be seen keeping crucial systems running.

At the memorial in Tokyo, the Emperor thanked those who fought to bring the damaged reactors under control in the immediate aftermath of the quake and tsunami.

"I would like to take this opportunity to deeply thank the people who helped the victims and those in the disaster zones, and those who helped deal with the nuclear crisis," he said, with the Empress Michiko at his side.

An anti-nuclear protest was planned in downtown Tokyo on Sunday amid growing public opposition to atomic power in the wake of the disaster, the worst since Chornobyl in 1986.

Officials imposed a 20-kilometre no-go zone around the Fukushima nuclear plant and tens of thousands of neighbouring people who lived in the area may never be allowed back.

Only two of Japan's 54 reactors are now running while those shut down for regular inspections undergo special tests to check their ability to withstand similar disasters. They could all go offline by the end of April if none are restarted before then.

The Japanese government has pledged to reduce reliance on nuclear power, which supplied about 30 per cent of the nation's energy needs before the disaster, but says it needs to restart some nuclear plants to meet Japan's energy needs during the transition period.

Prime Minister Yoshihiko Noda has acknowledged failures in the government's response to the disaster, being too slow in relaying key information and believing too much in "a myth of safety" about nuclear power.