Scientists Spot Trippy Waves Rippling Across Earth's Outer Core
The Editors - Yesterday 4:35 PM
A team of scientists in Belgium and France have discovered a new type of magnetic wave—called a Magneto-Coriolis wave—that courses across the surface of Earth’s outer core every seven years. The researchers analyzed years’ worth of satellite data from magnetic field-scanning satellites to build a model of the bizarre waves.
Earth’s magnetic field, also known as the “magnetosphere,” is vital in sustaining life on our planet. This vast bubble of charged particles wraps around our planet like a comet’s tail, protecting us from a barrage of both solar and cosmic radiation. In essence, it has turned Earth into a giant dipole magnet, helping to orient the navigation systems that direct everything from our smartphones to satellites.
Earth’s magnetosphere is generated in our planet’s outer core, a churning sea of molten iron roughly 1,800 feet below the surface. Electrically charged particles in the outer core form convective cells, which produce an electric current that forms what scientists call a “dynamo.” This process is what forms Earth's magnetic field, or magnetosphere.
Our magnetic field is a particularly weird one. It periodically flips, sending the magnetic north pole to the southern hemisphere and vice versa. (Fear not a reasonable amount: The last polar reversal occurred 780,000 years ago. Technically, we are overdue for a pole swap, but experts agree we’d probably be able to adjust.) In recent years—geologically speaking, that is—scientists have noticed other bizarre behavior. The magnetic north pole, for example, is slithering eastward at break-neck speed. And in one region between Africa and South America, the field is even weakening. While understanding these idiosyncrasies has become a priority for many earth scientists, there’s still a lot that we don’t know.
More:
https://www.msn.com/en-us/news/technology/scientists-spot-trippy-waves-rippling-across-earths-outer-core/ar-AAXLNOw?li=BBnb7Kz
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By Brandon Specktor published about 14 hours ago
The waves creep across the outer core every seven years.
An illustration showing mysterious waves (red) moving across the outermost layer of Earth's outer core. (Image credit: Planetary Visions (credit: ESA/Planetary Visions))
Scientists have detected a completely new type of magnetic wave that surges through Earth's outer core every seven years, warping the strength of our planet's magnetic field in the process.
The waves — dubbed "Magneto-Coriolis" waves because they move along the Earth’s axis of rotation, per the Coriolis effect — creep from East to West in tall columns that can travel up to 930 miles (1,500 kilometers) per year, the researchers wrote in a March 21 paper in the journal Proceedings of the National Academy of Sciences. Using a fleet of European Space Agency (ESA) satellites, the team pinpointed the mysterious waves to the outermost layer of Earth's liquid outer core, right where that layer meets the rocky mantle — roughly 1,800 miles (2,900 km) below the planet's surface.
According to the researchers, the existence of these waves could help explain mysterious fluctuations in the planet's magnetic field, which is generated by the movement of liquid iron in the planet's outer core. Satellite measurements of the magnetic field taken over the last 20 years show that the field's strength dips every seven years or so, coinciding with the oscillations of these newfound waves.
"Geophysicists have long theorized over the existence of such waves, but they were thought to take place over much longer time scales," lead study author Nicolas Gillet, a researcher at the Grenoble Alpes University in France, said in a statement. "Our research suggests that other such waves are likely to exist, probably with longer periods — but their discovery relies on more research."
More:
https://www.livescience.com/magneto-coriolis-waves-outer-core
