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Scale model of Earth reveals clues about the planet’s magnetic field
The Earth’s magnetic field protects the surface against harmful cosmic and solar radiation
Friday 01 November 2024
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A scientific scale model of Earth is helping to reveal clues about the planet’s magnetic field.
The Earth’s magnetic field protects the surface against harmful cosmic and solar radiation, and for years researchers have been trying to decipher the mechanism of how it is created by an electric current in the layer of liquid iron that surrounds the solid core of the Earth.
And now The Little Earth Experiment, conducted by Coventry University’s Research Centre for Fluid and Complex Systems, is helping to reveal those answers.
The experiment, designed by Centre director Professor Alban Pothérat and his PhD student Kélig Aujogue, created a scale model of the Earth’s liquid core which was then placed inside a large magnetic field at the European Magnetic Field Laboratory in Grenoble, France.
The dome-shaped model was filled with transparent sulfuric acid so the flow movement inside the dome could be followed with cameras and mirrors. While it was previously believed that the flow was divided into two independent sections on either side of a cylinder that follows the width of the solid core along the planet’s rotation axis, the experiment showed that the flow can cross this boundary.
We realised that the magnetic field breaks the constraint that separates these regions, so I went back to the drawing board and extended the theory to include the effect of the magnetic field. This is a big change in our understanding of these flows.
Professor Alban Pothérat
It is believed that the results of the research – funded by the Leverhulme Trust and published in Physical Review Letters – can help astrophysicists who look at planets outside our solar system, as the presence of planetary magnetic fields elsewhere in the universe are one of the elements that indirectly helps with the development of life.
Closer to home, studying the Earth’s magnetic field will help researchers understand what happens when it disappears, for example during the short period when magnetic poles flip.
It's very important to understand how it's generated, because it’s possible that the magnetic field could suddenly shut down. The Earth would then lose its vital protective shield, be it temporarily.
The flow in the outer core produced the Earth’s magnetic field so in a change in its structure can lead to such an event. What makes it shut down is directly linked to what happens inside the core.
Professor Alban Pothérat
Find out more about the Research Centre for Fluid and Complex Systems.
