Earth's magnetic field is 3.7 billion years old!

Researchers have revealed that Earth's magnetic field was almost the same 3.7 billion years ago as it is today.

According to a report in Discover Magazine, researchers from the University of Oxford and the Massachusetts Institute of Technology (MIT) discovered that Earth's current magnetic field is nearly identical to what it was 3.7 billion years ago by using 3.7-billion-year-old rocks.

Through a meticulous study using rocks extracted from the Isua Greenstone Belt on the island of Greenland, researchers found that the magnitude of the magnetic field 3.7 billion years ago was 15 microteslas. This magnitude is equal to half the strength of the modern magnetic field.

This achievement by the researchers was obtained by studying iron particles in ancient rocks that act as natural magnets by recording the magnitude and direction of the magnetic field.

The magnetic field protects the Earth from cosmic radiation and solar winds.

The Isua Greenstone Belt, located 150 kilometers northeast of Nuuk, the capital of Greenland, contains some of the oldest rocks on Earth.

"AN IMPORTANT STEP"

Claire Nichols, a geoscientist at the University of Oxford and lead author of the study, stated in a press release that the findings are an important step in trying to understand the role of the ancient magnetic field as life was just emerging on Earth.

Nichols noted that extracting reliable findings from a 3.7-billion-year-old rock is quite difficult, and that it was exciting to see the primary magnetic signals emerge when they analyzed the samples in the laboratory.

Finding rocks that show the age of Earth's magnetic field is quite difficult. Heat found along tectonic plates can alter any preserved evidence in the rocks.

However, the rocks found on the island of Greenland were located on thick continental crust that protected them from heating.

Researchers plan to extract ancient rocks from Canada, Australia, and South Africa for future studies.

More evidence regarding the age of the magnetic field and how it evolved could help researchers understand whether a magnetic field is necessary to support life.

The research was published in the journal "Journal of Geophysical Research".