Chile Quake Shifted Earth's Axis, Shortened Day

The magnitude 8.8 earthquake that hit Chile may have actually shifted the Earth's axis, shortening the length of a day, a NASA scientist says. Moving hundreds of kilometers of rock changes the earth's distribution of mass, and, in turn, changes the planet's rate of rotation. In this case, the axis likely shifted by about 3 inches, shortening the day by about 1.26 microseconds.

This is not the first, or only, time an earthquake has had such an impact, BusinessWeek notes. The magnitude 9.1 earthquake that generated the 2004 tsunami shortened the day by 6.8 microseconds. Changes near the epicenter of a quake are more perceptible: The island of Santa Maria, off the Chilean coast, may have been pushed upward by about 2 meters, scientists say.
(More Chile earthquake stories.)