Quake shifted island, sped up Earth's rotation

Sun Mar. 13 2011
CTV.ca News Staff

The changes may be imperceptible to most people, but the massive earthquake that struck off the coast of Japan Friday had a startling impact on the Earth, experts say. The 8.9-magnitude quake moved Japan's main island by more than two metres, in addition to shifting Earth on its axis and briefly speeding up its rotation.

Early data from Japan suggests the earthquake moved the island about 2.4 metres, according to Kenneth Hudnut of the U.S. Geological Survey. The agency compared information from a GPS station that had moved by more than two metres with satellite images from Japan.

Late Friday, scientists at NASA revealed the quake shaved more than a microsecond from the day. The quake, which lasted about two minutes, sped up the earth's rotation by about 1.6 microseconds. (One microsecond is one-millionth of a second.) NASA geophysicist Richard Gross said the quake shifted the Earth's mass, which caused the change in speed. the rest