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Stark warning from Inch quake
expert
14.03.11
AN Inishowen-based
earthquake expert said Japan's disaster could rank
in the top five most powerful quakes ever
recorded.
And Inch Island resident Prof John McCloskey, a
geophysicist at the University of Ulster, warned
that Friday's earthquake off Sendai, could trigger
an even greater catastrophe.
“We already know a lot about it and more information
is coming in all the time,” he said. “The earthquake
happened where the Pacific plate is being forced
under Japan in an interface called a subduction
zone.”
Prof McCloskey and his team in Coleraine have
already completed calculations on the size of the
displacement that caused the huge earthquake. They
estimate that a piece of the Eurasian plate at least
500km long and 200km wide pushed upwards between 4m
- 5m. |
“We are absolutely sure
this event today [off Sendai] was triggered by the
earlier quake,” Prof McCloskey said. “The event was
a truly globally massive earthquake. It is
definitely going to be one of the top 10 biggest
earthquakes of all time and could be in the top
five," the local scientist told 'The Irish Times'.
He said subduction quakes shake the earth but also
trigger tsunamis.
“The overriding plate basically bounces back up
after a period of 100 or more years, when the
elastic forces get too strong for the frictional
forces to hold. All the stress is released in a few
hundred seconds.”
He said people caught in a tsunami of even one metre
would almost |
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Prof John McCloskey. |
certainly not survive
while some of the waves that reached land were up to
10m.
He now warns that the risk of an even greater
catastrophe has been increased because of the Sendai
earthquake.
He said the quake would have caused stresses to
build further south along the line of subduction,
south of Tokyo.
“This quake will have increased stress in the area
south of Tokyo,” he said. Tokyo is about 100km
further down along the fault line and may be in
greater jeopardy as a result, he said. He said,
apart from tragic loss of life, an earthquake in
Tokyo would have a global impact.
“A big earthquake in Tokyo would have a world
impact. This [Sendai] earthquake will have cost less
than 1 per cent of Japan’s GDP. The economic impact
of a Tokyo earthquake is significantly bigger.” |
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