(ORDO NEWS) — It’s not very quiet inside the Earth. Deep below the surface, the planet is literally seething with activity, from plate tectonics to convection currents circulating in hot magma fluids.
Now scientists studying data from Earth’s satellites have discovered something inside the Earth that we’ve never seen before: a new type of magnetic wave that travels across the surface of our planet’s core every seven years.
This discovery may provide insight into how the Earth’s magnetic field is generated and allow us to understand the evolution of our planet, that is, the gradual cooling of the planetary interior. The team’s research was published in the journal PNAS.
“Geophysicists have long theorized about the existence of such waves, but it was believed that they occur on much longer time scales than our studies have shown,” says Nicolas Gillet, a geophysicist at the University of Grenoble-Alpes (France).
“Measurements of the magnetic field with instruments on the surface of the Earth indicated that there was some kind of wave action, but we needed the global coverage provided by measurements from space to show what was really happening.”
The Earth’s magnetic field has long been a subject of interest for scientists. Research to date shows that an invisible structure forms a protective “bubble” around our planet, trapping harmful radiation and the atmosphere. But the magnetic field is not static. It fluctuates in strength, size and shape, has features we do not understand and gradually weakens over time.
The European Space Agency’s Swarm orbiting satellites are three identical probes launched in 2013 that orbit the Earth to study activity inside the Earth. It was in this data that Gillette and his team found strange new waves.
They then looked at data from other ground and space observatories collected between 1999 and 2021 and found a pattern. These waves, known as magneto-coriolis waves, are huge magnetic pillars aligned along the Earth’s axis of rotation, strongest at the equator.
This exciting discovery opens a new window into a world we may never see. These mysterious waves oscillate every seven years and travel westward at speeds up to 1,500 kilometers per year.
Their existence suggests that there may be other magneto-Coriolis waves with different periods of oscillation that we cannot detect today due to lack of data.
As long as the waves carry information about the medium they travel through, the new discovery could be used to study the Earth’s interior in new ways – including the core, which is still difficult to study.
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