* Quake has preliminary magnitude of 7.3 - USGS
* 1-metre high tsunami hits Miyagi prefecture
* No immediate reports of death or injury
* Power stations, refineries report normal operations
TOKYO, Dec 7 (Reuters) - A strong quake centred off
northeastern Japan shook buildings as far away as Tokyo on
Friday and triggered a one-metre tsunami in an area devastated
by last year's Fukushima disaster, but there were no reports of
deaths or serious damage.
The quake had a preliminary magnitude of 7.3, the U.S.
Geological Survey said, and thousands of coastal residents were
ordered to evacuate to higher ground, but the tsunami warning
was lifted two hours after the tremor struck.
The March 2011 earthquake and following tsunami killed
nearly 20,000 people and triggered the world's worst nuclear
crisis in 25 years when the Fukushima-Daiichi nuclear plant was
destroyed, leaking radiation into the sea and air.
Workers at the plant were ordered to move to safety after
Friday's quake. Tokyo Electric Power Co, the operator
of the Fukushima nuclear plant, reported no irregularities at
its nuclear plants.
All but two of Japan's 50 nuclear reactors have been idled
since the Fukushima disaster as the government reviews safety.
The quake measured a "lower 5" in Miyagi prefecture on
Japan's scale of one to seven, meaning there might be some
damage to roads and houses that are less quake resistant.
The scale measures the amount of shaking and in that sense
gives a better idea of possible damage than the magnitude. The
quake registered a 4 in Tokyo
The one-metre tsunami hit at Ishinomaki, in Miyagi, at the
centre of the devastation from the March 2011 disaster. All
Miyagi trains halted operations and Sendai airport, which
was flooded by the tsunami last year, closed its runway.
Five people in the prefecture were slightly injured.
"I was in the centre of the city the very moment the
earthquake struck. I immediately jumped into the car and started
running away towards the mountains. I'm still hiding inside the
car," said Ishinomaki resident Chikako Iwai.
"...I have the radio on and they say the cars are still
stuck in the traffic. I'm planning to stay here for the next
couple of hours."
There are vast areas of Ishinomaki that still have not been
cleaned up since last year's tsunami. Many houses lie in ruins,
full of rubble. Workers by the shore still sort through
thousands of cars that were swamped and destroyed. The cars are
piled up and being taken apart for parts and scrap.
A QUAKE EVERY FIVE MINUTES
Narita airport outside Tokyo was back in action after a
brief closure for safety checks. There were small tsunamis,
measuring in the centimetres, elsewhere near the epicentre.
Last year's quake, which measured 9.0, triggered fuel-rod
meltdowns at Fukushima, causing radiation leakage, contamination
of food and water and mass evacuations. Much of the area is
still deserted.
The government declared in December that the disaster was
under control.
"Citizens are now escaping to designated evacuation centres
and moving to places on higher ground," office worker Naoki Ara
said in Soma, 30 km (18 miles) from the Fukushima-Daiichi plant.
Prime Minister Yoshihiko Noda cancelled campaigning in Tokyo
ahead of a Dec. 16 election and was on his way back to his
office, but there was no immediate plan to hold a special
cabinet meeting.
Public spending on quake-proofing buildings is a big
election issue.
Japanese were posting photos of their TV screens with
tsunami warnings on Facebook, asking each other whether they're
safe, confirming their whereabouts.
"It shook for a long time here in Tokyo, are you guys all
all right?" posted Eriko Hamada, enquiring about the safety of
her friends.
Phone lines were overloaded and it was difficult to contact
residents of Miyagi.
"Owing to the recent earthquake, phone lines are very busy,
please try again later," the operator said.
The yen rose against the dollar and the euro on the news,
triggering some safe-haven inflows into the Japanese currency.
Japan is one of the world's most earthquake-prone countries,
with a tremor occurring at least every five minutes.
Located in the "Ring of Fire" arc of volcanoes and oceanic
trenches partly encircling the Pacific Basin, the country
accounts for about 20 percent of the world's earthquakes of
magnitude 6.0 or greater.
Tokyo, with a population of 12 million, sits on the junction
of four tectonic plates: the Eurasian, North American,
Philippine and Pacific. The sudden bending or breaking of any
plate can trigger an earthquake.
