Earth’s Core Bounce Nudged Japan During 2011 Quake, New Study Finds

Scientists say the 2011 magnitude-9.0 Tohoku earthquake sent waves deep into Earth that bounced off the outer core and returned to the crust, causing nearly uniform eastward movement of mainland Japan across about 1,800 miles—roughly 5–6 millimeters—an unprecedented broad displacement with energy comparable to a magnitude-7.5 event, with potential implications for future seismic hazard understanding.