University of Leeds, U.K.
As the world turns ... its core does what?
This is Sandra Tsing Loh with the Loh Down on Science, and a churning drama of soap-opera proportions.
See, Earth's inner core is a solid iron ball a little smaller than the moon. A liquid layer of molten metal, called the outer core, flows around the inner core. Its metallic motion is what creates Earth's magnetic field.
Scientists probe the dual cores' mysteries by studying seismic waves that pass through. You know, from earthquakes.
Seismic data show that the inner core rotates to the east, while the outer core flows to the west! As an added bonus, the inner core rotates faster or "superrotates" – outpacing even the surface of the planet, thousands of miles above.
But why the directional difference? Scientists from the University of Leeds in England blame the planet's magnetic field. Using a Swiss supercomputer, they created a model of the earth's innards. And found that the magnetic field pushes the inner core in one direction. And tugs the outer core in the other.
Sounds turbulent! Thank goodness it's so calm here on the surface! Right.
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