More than 5,000 kilometers below our feet, liquid iron orbits a solid core, which forms the Earth’s protective magnetic field.
Although you can’t see the magnetic field with the naked eye, just look at images of the surface of Mars to get an idea of what Earth would have looked like without the solar wind shield, which protects us from radiation.
About 565 million years ago, the strength of the magnetic field on Earth suddenly decreased by 10% compared to today.
In a miraculous way, the Earth rearranged its magnetic field, before the planet exploded with multicellular life.
Researchers from the University of Rochester in the United States have in A new study published in Nature Communications He showed that the Earth regained its strong magnetic field in just a few million years.
At the same time, the Earth formed its solid inner core. Therefore, researchers believe that nucleation is the direct cause of magnetic field regeneration.
Locked crystals reveal age
The earth is made up of different layers. Explain simply, the crust is at the end of the planet, where all life forms. Below us lies the mantle, the thickest layer of the Earth.
Next comes the molten outer core and finally the inner solid core.
In a process called geodynamics, liquid iron circulates around the outer core, causing electric currents, which in turn create the Earth’s magnetic field.
For many years, geologists tried, but failed, to discover how the magnetic field of the Earth and its core changed, because they were unable to measure the magnetic field.
The deep location of the core and extreme temperatures make precise investigations impossible.
Fortunately, minerals that rise to the Earth’s surface contain tiny magnetic particles. Since they are rapidly cooled after becoming liquid, they are locked in the direction and intensity of the magnetic field.
To determine the age and growth of the Earth’s interior, the researchers used a carbon dioxide laser and an advanced measuring device with an equally advanced name – the Superconducting Quantum Interferometer magnetometer.
Through them they were able to analyze a group of aluminum silicate minerals called feldspar crystals. They found it in rocks from a deep magnetic rock called anorthosite.
The crystals are perfect for picking up magnetism, as they have tiny magnetic needles inside.
The important inner core
Because magnetism was confined to crystals, the researchers were able to see that 550 million years ago, the Earth’s magnetic field began to renew itself after losing it roughly 15 million years ago.
The speed formed the solid core of the Earth, which recharged the outer core and restored the strength of the magnetic field.
The new measurements can’t tell us anything about Earth’s history or future, but they can tell us how other planets might form magnetic shields to protect potential life from radiation.
Researchers believe that Mars, for example, had blue oceans and an Earth-like magnetic field. But the magnetic field disappeared, leaving the planet exposed to the solar winds that left the planet’s surface dry.
So the study shows that the inner core, which can maintain the planet’s magnetic field, is necessary for life to thrive.
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