Fukushima plant now more vulnerable to seismic risk

The Fukushima nuclear plant is more vulnerable to seismic risk after the powerful quake that rocked Japan last year.

The power plant witnessed one of the worst nuclear disasters in history after it was damaged by the March 11, 2011 magnitude 9 earthquake, about 160 km from the site.

The new study, based on data from over 6,000 earthquakes, shows the March tremor caused a seismic fault close Fukushima plant, generating fears that one much closer to it could occur in future, the journal Solid Earth reports.

"Given that a large quake occurred in Iwaki not long ago, we think it is possible for a similarly strong earthquake to happen in Fukushima," says team-leader Dapeng Zhao, geophysics professor at Japan's Tohoku University.

The April 11, 2011 magnitude 7 Iwaki earthquake was the strongest aftershock of the March 11 earthquake with an inland epicentre. It occurred 60 km southwest of the Fukushima nuclear power plant, or 200 km from the March 11 epicentre, according to a Tohoku statement.

The research shows that the Iwaki earthquake was triggered by fluids moving upwards from the subducting Pacific plate to the crust.