23 January 2012
Last updated at 10:29 ET
The 2011 quake caused massive destruction on Japan's north-eastern coastline
The 2011 quake caused massive destruction on Japan's north-eastern coastline
A
big earthquake is much more likely to hit the Japanese capital, Tokyo,
in the next few years than the government has predicted, researchers
say.
The team, from the University of Tokyo, said there was a 75%
probability that a magnitude 7 quake would strike the region in the
next four years.
The government says the chances of such an event are 70% in the next 30 years.
The warning comes less than a year after a massive earthquake and tsunami devastated Japan's north-eastern coast.
The last time Tokyo was hit by a big earthquake was in 1923,
when a 7.9 magnitude quake killed more than 100,000 people, many of them
in fires.
Researchers at the University of Tokyo's earthquake research
institute based their figures on data from the growing number of tremors
in the capital since the 11 March 2011 quake.
They say that compared with normal years, there has been a
five-fold increase in the number of quakes in the Tokyo metropolitan
area since the March disaster.
They based their calculations on
data from Japan's Meteorological Agency, They said their results show
that seismic activity had increased in the area around the capital,
which in turn leads to a higher probability of a major quake.
The researchers say that while it is "hard to predict" the
casualty impact of a major quake on Tokyo, the government and
individuals should be prepared for it.
Correspondents say that while the university calculations
take account of greater seismic activity since March, government
calculations may use different or less up-to-date data and different
modelling techniques.
The 9.0 magnitude earthquake last year aksi crippled the
cooling systems at the Fukushima nuclear power station, causing
meltdowns in some of its reactors.
Japan is located on a tectonic crossroads dubbed the "Pacific
Ring of Fire" which is why its is commonly regarded as one of the
world's most quake-prone countries, with Tokyo located in one of the
most dangerous areas.
