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Tue. Jul 23rd, 2024

The “near collapse” of Earth’s magnetic field in the distant past could have held the key to complex life » TwistedSifter

By Vaseline May27,2024
The “near collapse” of Earth’s magnetic field in the distant past could have held the key to complex life » TwistedSifter

The “near collapse” of Earth’s magnetic field in the distant past could have held the key to complex life » TwistedSifterThe “near collapse” of Earth’s magnetic field in the distant past could have held the key to complex life » TwistedSifter

We know a lot about how the Earth began and how we evolved from the primordial sludge to the marginally evolved people and planet we see today.

However, there are many mysteries and scientists believe that the “near collapse” of Earth’s magnetic field 590 million years ago could be the key to unlocking at least one of them.

Earth’s magnetic field has changed direction more than a handful of times over millions of years, and sometimes that means a temporary weakening.

Between 591 and 565 million years ago, the field declined for much longer than normal, and soon afterward the first complex animals appeared in the geological record.

This study suggests that this may have made complex life possible.

Our geomagnetic field is one of the things that is different about Earth than, for example, Venus or Mars. It acts as a shield against coronal mass ejections that would cause enormous amounts of radiation, and helps the planet resist the stripping of its atmosphere and the harsh solar winds.

Source: ShutterstockSource: Shutterstock

Scientists believe that any extraterrestrial life can be found on a planet with a similar, powerful magnetic field.

You would think that this necessity would mean that a weakening in the field would be a cause for concern, but scientists have tried and failed to link mass extinction events to previous weakenings.

591 years ago was the lowest field ever recorded, just 1/30th of modern levels, and yet they think this could have made a big difference.

The study authors claim that fields less than 10% of those today persisted for 26 million years, including one of the most vital periods for life.

The animals that existed before were microscopic and/or stationary species. Only after that, about 560 million years ago, did the first active creatures (Ediacaran fauna) first appear in the fossil record.

Source: Ryan Somma Source: Ryan Somma

Experts believe that an increase in oxygen made its way to the ocean and was the necessary ingredient to fuel complex and highly mobile animals. However, they are not sure how much extra oxygen was present.

Either way, the increase in oxygen levels was a huge game changer – and Tarduno and their co-authors think the weakening of the magnetic field could be causing it.

A weaker field translates to more hydrogen escaping the atmosphere, and with less hydrogen able to bond with oxygen, they believe a life-changing shift has occurred.

The authors do admit that it is difficult to model how much more oxygen would have been available due to the weaker field.

“Quantifying hydrogen loss for ultra-low field Earth is challenging because it is observationally inaccessible. Existing models predict an increase in hydrogen loss of 30 to 1,000 percent, and this enormous variation creates a lot of uncertainty about the resulting oxygen increase.”

Still, they think the increase could have been large enough to allow for the Ediacaran fauna.

“The highest estimates could result in a few percent change in oxygen… which could represent a disruption or exceedance of a threshold, allowing Ediacaran animal diversification.”

Source: EOL Learning and Education Group Source: EOL Learning and Education Group

They propose that the protective field could have shrunk so much that the plasma in the upper atmosphere was exposed to the solar wind, significantly increasing the loss of hydrogen ions.

It certainly sounds like something unique was starting around that time, and the lowered magnetic field could have played a role in that.

I wonder if we will ever get a complete picture of how the Earth evolved into our modern version.

If you found that interesting, you might like to read about the mysterious ‘pyramids’ discovered in Antarctica. What are they?

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