P

ARIS: The earthquake that set off the tsunami that caused the Fukushima nuclear plant disaster in 2011 was unleashed by a stealthy nine-year buildup of pressure on a plate boundary, scientists said Tuesday.

Part of a fault where two mighty plates on the Earth'€™s crust collide east of Japan was being quietly crushed and twisted for nearly a decade, they said.

The deformation '€œincreased the stress in the source region [...] and finally triggered the earthquake,'€ said study co-author Kazuki Koketsu of the University of Tokyo.

The earthquake, occurring below the Pacific floor about 200 kilometers east of the east coast city of Sendai, was one of the biggest ever recorded, measuring 9.0 on the moment magnitude scale.

The research builds on previous initiatives to harness GeoNet data, which has millimetric accuracy of land motion.

'€œOur paper proved that [the GeoNet] network of GPS stations can monitor a slow event which may lead to a great subduction earthquake,'€ said Koketsu.

The paper appears in the journal Nature Communications. '€” AFP