Japan’s 2011 Tohoku Earthquake is located at the boundary between the Pacific plate and the North American plate (this is not a typo!). These plates are converging at about 8 cm/year.
The rectangle in the figure shows the location and length of the rupture zone. The red star indicates the epicenter. The rupture was bilateral, i.e., it spread away from the epicenter in both the north and south directions, taking about 2 minutes to cover a total of 400 km (250 miles). This magnitude 9.0 earthquake was more than 500 times stronger than the recent January 12 Haiti earthquake.
The colors show the slip amplitude (i.e., the amount by which the land on one side of the fault moved with respect to the land on the other side). The motion was mainly thrust-fault (see animation).
The rupture originated about 24 km (15 miles) below the surface. In some places, the slippage along the fault was as large as 30 meters (100 feet), shown by red-shaded areas. The coast of Japan sprang east, into the ocean, in some places by as much as 5 m (16 feet).
The sea floor offshore North Honshu was thrust up and seaward, creating a devastating tsunami (SEE ANIMATION). The tsunami hit the coast of Honshu within tens of minutes and propagated across the whole Pacific, hitting Hawaii and the coast of California in about four hours and 10 hours, respectively, after the mainshock (SEE SIMULATION).