Japan's seismologists 'blinded to March 11 quake'

An elderly woman walks amongst tsunami damage in the town of Yamada, Iwate prefecture. Japan's seismologists were so fixated by the risk of a big quake on the southern Pacific coast that they had become 'blinkered' to the risk of the March 11 magnitude 9.0 earthquake. -- PHOTO: AFP

PARIS - JAPAN'S seismologists were so entrenched in outdated beliefs about seismic hazard that they became blinkered to the risk of the March 11 mega-quake, a commentary in a top science journal charged on Wednesday.

Writing in the journal Nature, Robert Geller, an American who is professor of seismology at the University of Tokyo, said Japanese government scientists had become fixated by the risk of a big quake on Japan's southern Pacific coast.

This had skewed their view of the risks for the country's north-east, where the 9.0-magnitude quake and tsunami left more than 26,500 people dead or missing, he said.

Prof Geller pointed the finger at a belief, entrenched for decades, that Japan faces imminent risks of a huge earthquake in a plate boundary off the southern coasts of Honshu and Shikoku. Government-made hazard maps of the Tokai, Tonankai and Nankai 'earthquake zones' are hugely promoted in public awareness campaigns and have gained the status of holy writ, he said.

But, said Prof Geller, these maps are based on two assumptions, the 'characteristic earthquake' and 'seismic gap' theories, which date from the 1960s and 70s and have not been supported by evidence.

'This misleads the public into believing that the clock is ticking down inexorably on a magnitude-eight earthquake that is certain to strike the Tokai district in the near future,' he said. 

-- AFP