LEEDS, England, Dec. 19 (UPI) -- New X-ray images of Earth's outer core have revealed a unique jet stream-like current of molten iron. The revelatory images were captured by European Space Agency's Swarm satellites.
"We've not only seen this jet stream clearly for the first time, but we understand why it's there," Phil Livermore, a researcher at the University of Leeds, said in a news release. "We can explain it as an accelerating band of molten iron circling the North Pole, like the jet stream in the atmosphere."
Previous measurements of fluctuations in Earth's magnetic field have offered scientists only a vague understanding of the movement of molten rock thousand miles beneath the planet's crust. The new images offer clarity and detail.
Molten iron in the newly discovered iron jet stream travels 25 miles per year -- several hundred times faster than iron elsewhere in the core and several thousand times faster than drifting tectonic plates.
The jet stream is positioned between two distinct regions of the core. Scientists believe iron is drawn to this boundary region and squeezed in a single direction. It's likely buoyancy forces and the core's magnetic field also contribute to the jet stream's trajectory.
Earth's magnetic field is generated by a variety of sources, including the core, mantle, crust, oceans, ionosphere and magnetosphere. ESA's Swarm satellites have allowed scientists to untangle the various sources and study each individually.
Scientists believe the latest discovery of the iron jet stream -- detailed in the journal Nature Geoscience -- is only one of many to come.
"Further surprises are likely. The magnetic field is forever changing, and this could even make the jet stream switch direction," said Rune Floberghagen, Swarm mission manager. "This feature is one of the first deep-Earth discoveries made possible by Swarm. With the unprecedented resolution now possible, it's a very exciting time -- we simply don't know what we'll discover next about our planet."