JAPAN-QUAKEThe earthquake that set off the tsunami which caused the Fukushima nuclear plant disaster 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. It was this hard to detect activity which caused the fault eventually to rip open on March 11, 2011 and cause the catastrophe. The deformation “increased the stress in the source region… and finally triggered the earthquake,” said study co-author Kazuki Koketsu of the University of Tokyo. “It had an impact on the occurrence time of the earthquake,” Koketsu told AFP by email. “It advanced the time (of the quake) by about one year.” The earthquake, occurring below the Pacific floor about 200 kilometres (120 miles) east of the east coast city of Sendai, was one of the biggest ever recorded, measuring 9.0 on the moment magnitude scale. More