The Geology of the March 11 Quake

It must be a rare event when a whole country gets shoved out of its place in geography, and that is what happened to Japan on March 11. An AP reporter explains it as follows:

"Japan's northern half sits on the North American tectonic plate. The Pacific plate, which is mostly undersea, normally slides under this plate, slowly nudging the country west. But in the earthquake, the fault line between the two plates ruptured, and the North American plate slid up and out along the Pacific plate.

The rising edge of plate caused the sea floor off Japan's eastern coast to bulge up — one measuring station run by Tohoku University reported an underwater rise of 16 feet (5 meters) — creating the tsunami that devastated the coast. The portion of the plate under Japan was pulled lower as it slid toward the ocean, which caused a corresponding plunge in elevation under the country.

Some areas in Ishinomaki[in Miyagi Prefecture] moved southeast 17 feet (5.3 meters) and sank 4 feet (1.2 meters) lower."

For the full article, go to:
http://news.yahoo.com/s/ap/20110509/ap_on_re_as/as_japan_earthquake_changing_terrain