When you think of a jet stream, you probably think of air currents in the atmosphere, but new data from the European Space Agency has revealed a molten jet stream hurtling through Earth’s outer core. The agency’s Swarm satellites are unearthing surprising revelations about the depths of our planet, the most recent of which travels mainly beneath Siberia and Alaska three times faster than the average outer core element. And it’s speeding up.
The core’s jet stream is made of molten iron, and flows at a speed of over 40 kilometers, or around 25 miles, per year. And if that pace doesn’t sound too fast, it’s actually hundreds of thousands of times quicker than tectonic plates move. Scientist Phil Livermore, who is the lead author on a paper penned by three researchers about the jet stream, described the jet stream as “acceleration in a band of core fluid circling the pole.” The jet stream occurs when liquid in the core moves towards a boundary between two regions and is “squeezed out sideways,” according to ESA.
The jet stream is part of “an ocean of superheated, swirling liquid iron that makes up the outer core,” according to ESA. The iron ocean makes possible Earth’s magnetic field, which protects us from solar winds and radiation. Swarm satellites are studying the magnetic field, and the information could help researchers learn about how core iron moves. Study co-author Chris Finlay said we know more about the Sun than we do Earth’s core, but Swarm information could change that, and scientists are very hopeful this thrilling discovery could be followed by others.
Swarm mission manager Rune Floberghagen said, “Further surprises are likely. The magnetic field is forever changing, and this could even make the jet stream switch direction. 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.”
The journal Nature Geoscience published the work of the scientists online earlier this week.