If three major earthquakes were to occur simultaneously off the Pacific coast of central and western Japan, tall buildings in Tokyo and Osaka could rock far longer than they did during the magnitude-9 temblor that hit the Tohoku region in March 2011, according to researchers.
Scientists at the Center for Integrated Disaster Information Research at the University of Tokyo said Monday that three magnitude-8.7 quakes occurring simultaneously in the area could trigger slow and long ground motions of the type that impact buildings located far from the epicenters.
They simulated long-period ground motions for a case in which the three earthquakes occur almost simultaneously off the Pacific coast from central to western Japan, and along the Nankai Trough in the Western Pacific, professor Takashi Furumura said.
The scientists estimated that buildings 60 stories or higher in Tokyo could be swayed two to three times more strongly than in the 2011 quake.