2011 quake boosted Tokyo's seismic risk

摘要

The magnitude 9 earthquake that shook Japan in March 2011 more than doubled the risk that a big quake will rattle Tokyo in the next five years, geologists report May 2 in Geophysical Research Letters. The 2011 quake hit 373 kilometers northeast of Tokyo. Afterwards, seismic activity around Japan's capital spiked, and small earthquakes are now three times as frequent as they were before the event. The ground movement comes from a piece of Earth's crust that's wedged between the Eurasian plate, on which Tokyo sits, and the Pacific plate, which slides into the mantle beneath the Eurasian plate.