Japan issues tsunami warning after 7.2 quake

Japan issued a tsunami warning Wednesday after a major 7.2-magnitude quake struck 160 kilometres (100 miles) east off the main Honshu island at 0245 GMT.

Updated: Mar 09, 2011, 14:54 PM IST

Tokyo: A major 7.3-magnitude offshore
earthquake rattled Japan Wednesday, swaying Tokyo buildings,
triggering a small tsunami and reminding the nation of the
ever-present threat of seismic disaster.

Police reported no casualties or property damage, and
operators of nuclear power plants and Shinkansen bullet trains
quickly gave the all-clear, while the wave hitting the Pacific
coast measured just 60 centimetres.

The tremor struck in the late morning about 160
kilometres offshore and 430 kilometres northeast of Tokyo, at
a shallow depth of 10 kilometres below the Pacific seafloor,
authorities said.

In greater Tokyo -- the world`s most populous urban
area with more than 30 million people -- the earthquake and a
succession of tremors that quickly followed were uncomfortably
felt as they shook buildings.

Television channels immediately cancelled their
programming to transmit information on the quake and a coastal
tsunami advisory.

It soon became clear the quake had left Japan
unscathed, but it was yet another uncomfortable reminder that
the threat of "the Big One" is a reality of daily life.

Japan, is located on the "Pacific Ring of Fire" and
dotted with volcanoes, and Tokyo is situated in one of its
most dangerous areas.

The mega-city sits on the intersection of three
continental plates -- the Eurasian, Pacific and Philippine Sea
plates -- which are slowly grinding against each other,
building up enormous seismic pressure.

The government`s Earthquake Research Committee warns
of a 70 per cent chance that a great, magnitude-eight quake
will strike within the next 30 years in the Kanto plains, home
to Tokyo`s vast urban sprawl.

The last time a "Big One" hit Tokyo was in 1923, when
the Great Kanto Earthquake claimed more than 140,000 lives,
many of them in fires. In 1855, the Ansei Edo quake also
devastated the city.
More recently, the 1995 Kobe earthquake killed more
then 6,400 people.

Small quakes are felt every day somewhere in Japan and
people take part in regular drills at schools and workplaces
to prepare for a calamity.

Families are urged to keep quake survival kits at
home, quake alerts can be sent via mobile phones and parks and
schools are sign-posted as quake shelters.
Nuclear power plants and bullet trains are designed to
automatically shut down when the earth rumbles and many
buildings have been quake-proofed with steel and
ferro-concrete at great cost in recent decades.