Earth’s magnetic field makes life on Earth possible as it protects our planet from harmful solar radiation. This magnetic field, as it exists today, has two poles — north and south. But it turns out this arrangement was not always the case.
A new research carried out by scientists at the Carnegie Institution of Science, suggests that Earth may have had multiple magnetic poles in the past.
In fact, there were periods in Earth’s history, between 500 million and 1 billion years ago, when something strange happened to Earth’s magnetosphere and the planet may have been enveloped in a multipolar magnetic field.
The planet Earth has magnetic nature because of its core which is made of molten iron. Earth’s core was not solid from the start but it was once molten and later it started to solidify. Researchers believe that ancient Earth had multiple poles for some time during the transition and wanted to test the magnetic properties of earth when it had molten core.
For the study, researchers examined rocks that had magnetic properties since their formation. Scientists know that Earth was dipolar for nearly 4 billion years, but something happened to its dipolar nature between 0.5 and 1 billion years ago (also known as Neoproterozoic Era).
“These findings could offer an explanation for the bizarre fluctuations in magnetic field direction seen in the geologic record around 600 to 700 million years ago,” Driscoll added. “And there are widespread implications for such dramatic field changes.”
The findings were published in Geophysical Research Letters.