Scientists Say Earth’s Center Rotates Faster Than Surface

As the earth turns, the center of the earth turns even faster.

Confirming assertions first made in 1996, a team of geophysicists are presenting data in the journal Science today showing that the earth’s inner core, a ball of solid iron larger than the moon, spins faster than the rest of the planet. Over a period of 700 to 1,200 years, the inner core appears to make one full extra spin.

That extra spin could give scientists information about how the earth generates its magnetic field.

The inner core, 1,500 miles wide, sits at the center of the planet, ensconced in a sea of hot liquid metal known as the outer core. With nothing to hold it in place, the inner core can rotate independently. Nearly a decade ago, two scientists at Lamont-Doherty Earth Observatory of Columbia University said it did just that.

By KENNETH CHANG

Full Story: http://www.nytimes.com/2005/08/26/science/26core.html