Home / Science / Earth's magnetic field nearly collapsed 565 million years ago

Earth's magnetic field nearly collapsed 565 million years ago

Artistic concept of the geodynamo and magnetic field of the earth during a pole reversal. Image: NASA

Earth's magnetic field, which protects life from intense sunlight, nearly collapsed 565 million years ago, according to a study published on Monday Nature Geoscience .

When the Magnetic Field Collapsed Life on Earth would have been very challenging because the solar wind would probably distract the planet from its atmosphere and hit the surface with harmful radiation.

Fortunately, the molten core of our planet began to solidify during the late Ediacaran period, according to the new release. This recharged magnetic field of the Earth was at its weakest point. Now, half a billion years later, Earth's magnetic field is ten times stronger than it was at this early time.

Scientists led by Richard Bono, a researcher of paleomagnetism at the University of Rochester, used ancient crystals from a site near the city of Sept-Îles, Quebec, to create this timeline of inner "nucleation" or solidification of the Earth to reconstruct.

It is believed that the core of the earth was completely fluid at some point, and the question of when it began to solidify has baffled scientists for decades. Estimates of the past ranged between 500 million and 2.5 billion years. The Bono team is now providing evidence that it began 565 million years ago.


Inner Earth Model: Kelvin Song

The inner core of the Earth is a solid iron-nickel alloy that is as hot as the surface of the Sun (about 5,430 ° C). This nucleus is surrounded by a fluid outer core that drives the Earth's magnetism with its convection cycles. The inner core grows slowly by "freezing" molten iron and nickel to its mass, a process that pumps heat into the outer core and strengthens the Earth's magnetic field.

Crystals were key in investigating researchers because Earth's magnetic field leaves their field Fingerprinting in some minerals by influencing the direction and orientation of lattice formation Researchers studied feldspar and pyroxene crystals from Ediacaran-aged rocks near Sept -Îles, which showed that the magnetic field was broken during the late Ediacaran by the reversal of his Polari 20 times faster than today.

These are signs of an impending geodynamic collapse, the team reported. The fact that the field became stronger after this time than collapse suggests that nucleation began and the Earth's dynamo gave the juice it needed to build the field.

The timeline suggested by Bono and his colleagues suggests that the nucleation occurred just before the Cambrian explosion, a period of enormous evolutionary progress 541 million years ago, which led to the rapid emergence of animal life.

Read more: Take a look at these trippy NASA visualizations of space magnetism

Evidence of weak magnetism in the late Ediacaran period has led some scientists to assume that the Earth is without strong field was irradiated erasure event. The organisms that could have had an advantage during this period were mobile or hard-shelled species that could protect themselves from radiation, and they flourished at the beginning of the Cambrian era.

Bono and his colleagues mention this speculative correlation, but note There is no general consensus on whether the weak magnetic field is related to the Cambrian explosion

"The Ediacaran era of ultra-low geomagnetic field strength is intriguing," they write Authors in the newspaper. "Proposals that decreased magnetic shielding has had an impact on the profound changes in animal development that characterized this and the subsequent early Cambral interval are controversial."

Further research is needed to improve our understanding of it how and if there are fluctuations in this area The magnetic intensity of the earth influenced the evolution of life. Bono and his colleagues have presented compelling evidence to resolve the debate on the age of the core of the earth.

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