- Earth’s magnetic poles flipped over 42,000 years ago, which could be the cause of a global climate crisis New study Found.
- The resulting changes in temperature and radiation levels may have killed many of the large mammals.
- This event may have ultimately contributed to the extinction of Neanderthals.
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Earth experienced a lot of turbulence when its magnetic poles flipped 42,000 years ago.
Scientists have known about this coup since the late 1960s. Earth’s magnetic poles are not static – they are generated by electrical currents from the planet’s liquid outer core, which is constantly moving. Recently, Earth’s magnetic north pole has I wandered big On a road towards northern Russia.
But for the most part, scientists did not believe that the recent flip in the pole had a significant environmental impact. Sure, the planet’s magnetic field became weaker, allowing more cosmic rays to penetrate the atmosphere, but plant and animal life was not known to be affected significantly.
a New study It now indicates an even more dramatic phenomenon: the extra cosmic rays may have depleted ozone concentrations, opening the door to more ultraviolet rays in the atmosphere. Changing weather patterns may have expanded ice cover over North America and dried up Australia, resulting in the extinction of many large mammal species. Meanwhile, a solar storm may have prompted ancient humans to seek shelter in the caves.
As competition for resources increases, our closest human extinct relative, Neanderthals, may have died.
“It could have been a very frightening time, almost like the end of days,” said Chris Tourney, an Earth scientist at the University of New South Wales, in a video describing the new research.
Scientists have not agreed on a specific theory as to why Neanderthals disappeared. Some research suggests Their extinction occurred naturallyNeanderthals intermarried with modern humans or the population became too small to hunt, mate and raise children. Other scientists hypothesized that Neanderthals may have been Compete for resources When modern man began to spread Europe.
Tierney’s study indicates that the death of Neanderthals is not an accident after a major shift in the Earth’s magnetic poles.
Its co-author, Alan Cooper, said, “It was only when I started talking between different fields of science that you could see the connections.” “Before that, none of the different areas had solved 42 [42,000 years ago] It was the main event. “
Ancient trees and caves bear clues of a potential climate catastrophe
To find out what happened to Earth’s climate 42,000 years ago, scientists asked a New Zealander who was alive at the time: the ancient kauri tree. The tree’s rings serve as a record of the levels of radiocarbon – a radioisotope – in the atmosphere over tens of thousands of years. In fact, the rings showed evidence of radiocarbon rise as the magnetic fields flipped, an event known as the “La Champagne Journey”.
The event is not unique in the history of our planet: the British Geological Survey Estimates That four or five polar fluctuations occur every million years.
During these reflections, the magnetic shield that protects our planet from the solar wind (the charged particles flowing from the sun) weakens. Earth’s magnetic north and south pole – not to be confused with the geographic points of the planet’s far north and south – swap places.
The Laschamps flight, the most recent example of this magnetic flip, likely occurred over a period of 1,000 years. This is a moment in the life of Earth, but long enough to change the fate of those who live on this planet.
“In this process of flipping from north to south and from south to north, the Earth’s magnetic field has virtually disappeared,” Tierney said. “The planet is opened to all these high-energy particles from outer space.”
If the sun emits very high levels of radiation in a solar storm during that period, then Neanderthals may need to search for cover.
In fact, La Champagne’s voyage coincided with an increase in cave use across Europe and Southeast Asia. In particular, researchers have found red ocher handprints in caves of the area dating back about 40,000 years. According to the new study, this pigment could be an old form of sunscreen.
Another magnetic reversal could be ‘imminent’
Not all researchers were convinced by Tierney and Cooper’s analysis. Chris Stringer, anthropologist at the Natural History Museum in London, He told the Guardian That although Lachamp’s journey may have contributed to the demise of Neanderthals, it is difficult to know exactly when they died.
“They have really survived for a longer period and have ranged on a wider scale than just Europe, and we have a very weak fix on the timing of their eventual disappearance across swaths of Asia,” Stringer said.
University of Florida geologist James Chanel, He told NPR Historical records of ice boa dating back 42,000 years do not indicate a global climate crisis. However, he added, “there appears to be a link” between the extinction of large mammals and the weakening of the Earth’s magnetic field.
At the very least, the new study provides a hint about what would happen if magnetic north and south flipped again.
Scientists know that Earth’s magnetic field has weakened by about 9% in the past 170 years. The magnetic north pole has also been drifting much faster since the 1990s, at a rate of 30 to 40 miles per year.
This “increased speculation that field reversal may be imminent,” the researchers write. Such an event could bring down energy and space networks. Increased radiation could expose more people to diseases such as cancer.
But scientists doubt that any potential magnetic reversal will be in its infancy. Earth’s magnetic field is still much stronger than it was the last time the poles flipped.