Magnetic fields are essential for life on Earth’s surface because they protect the planet from the solar wind. Unfortunately, about 565 million years ago, the strength of the magnetic field decreased to 10 percent of its current strength. Then the magnetic field mysteriously bounced back, regaining its strength before the Cambrian explosion of multicellular life on Earth.
This regeneration occurred within a few tens of millions of years and occurred at the same time that Earth’s dense core was forming, suggesting that the core may be the direct cause, according to new research from scientists at the University of Rochester.
The research, published in Nature Communications, provides clues about Earth’s history and future development and how it became a habitable planet.
John Tarduno, William R. Kenan, Jr. says: Professor of Geophysics in the Department of Earth and Environmental Sciences and Dean of Research in Arts, Science and Engineering at Rochester.
Researchers have used palaeomagnetism – the study of magnets trapped in ancient crystals – to pinpoint two important dates in the history of the inner core, and they believe bring back Earth’s magnetic field.
First, the dense inner core began to grow about 550 million years ago, and second, about 450 million years ago, the structure of the growing inner core changed, marking the boundary between the inner and outer core.
How can Earth avoid a Mars-like fate?
Researchers believe that Mars once had a magnetic field, but that field disappeared, leaving it vulnerable to solar winds and surfaces without oceans. It is unclear whether the absence of a magnetic field caused Earth to suffer the same fate.
Earth will surely lose a lot of water if the earth’s magnetic field is not renewed. “This planet will be drier and different from today’s planets,” said Tarduno.
More details can be found here.
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