Earth’s magnetosphere doesn’t just endow ourplanet with north and south magnetic poles. It also protects us from the solar wind and cosmic radiation. However, this invisible force is rapidly weakening. And so much so that scientists even begin to say that after some time the magnetic field can turn over, and the poles of the planet will change places.
No matter how crazy it sounds, but this is alreadyhappened before. The last time the inversion occurred about 780,000 years ago and, according to some scientists, it can happen again after about 40,000 years. With the latter, scientists are not sure, and it is precisely this uncertainty that makes us look for answers. At the same time, researchers say that even if this polarity reversal does happen in the future, it will not happen quickly, but over several thousand years.
Of particular interest to scientists at the momentrepresents the so-called South Atlantic Anomaly (JAA) - a huge area of the planet’s magnetic field, extending from Chile to Zimbabwe. It is this phenomenon, according to scientists, that is now causing the earth's magnetic field to weaken. Here his strength is so weak that it poses a threat to the orbiting satellites that can pass through it. Researchers shared their work in the journal Geophysical Review Letters.
Imagine the Earth’s magnetosphere is a peelan orange. Everything under this skin is protected from harmful influences from the outside. JAA, in turn, is a deep dent on this peel. All satellites located in the low Earth orbit of the Earth are also under the skin, but passing through the AAA (a dent in the skin), they come out of its protection, and their electronics become defenseless against destructive streams from space. That is why all devices suspend their work, flying over the AAA.
“We have long known that the magnetic field in thisarea is changing. But we did not know whether this was always characteristic of this region or this is a particular phenomenon, ”says physicist Vincent Hare of the University of Rochester (USA).
One of the reasons scientists know little aboutThe history of the magnetic field in this region of the Earth lies in the lack of archaeomagnetic data - physical evidence about the magnetism of the Earth that could be preserved in archaeological relics of the past.
However, one such evidence fromthe past has been preserved, and it is connected with the ancient African people living in the Limpopo River Valley, which extends to the territories of Zimbabwe, South Africa and Botswana - the regions that are currently located inside the South Atlantic Anomaly.
Life in Africa has always been difficult. But about 1000 years ago, when the inhabitants of these places faced special environmental difficulties, they performed sacred rituals. In times of especially dry seasons, people burned their clay dwellings and grain stores, thus trying to appease the gods and convince them to give the long-awaited rains. Certainly these ancient Africans did not even suspect that with their rituals they would create invaluable ground for scientific research for those who would live several centuries after them.
Clay, like everything existing on Earth, has a pronounced energy and has its own information field, which, among other things, may contain information about the magnetic field of the planet.
“When you heat clay to a certaintemperature, you actually stabilize the magnetic minerals contained in it. In these minerals, “printed” information about the magnetic field is erased and overwritten by data on the current state of the field, ”explains geophysicist John Tarduno.
In other words, an analysis of these clay artifactsIt allows scientists not only to find out more about the cultural characteristics of ancient nationalities that lived thousands of years ago in South Africa, but also to learn about what the Earth’s magnetic field was at that time.
“We were looking for signs of repetitive behavior, sowe believe that they are the reason for the existence of the South Atlantic anomaly today. And we really found them. This information helps us contextualize current changes in the magnetic field, ”says Tarduno.
The study found that the current easing inSAA is not a separate phenomenon in the history of the Earth, but has happened several times in the past. Similar changes, scientists say, should have been observed in 400-450 years. n e., 700-750 years. n e., as well as in 1225-1550. n e. And this information indicates that the location of the South Atlantic anomaly is not a simple geographical coincidence.
“We are starting to get strong evidence that Africa has something unusual. Something that can have an important effect on the general state of the Earth’s magnetic field, ”adds Traduno.
There is an assumption that the attenuation of magneticThe planet’s field, observed for about the last 160 years, is caused by the so-called “African low-speed mantle provinces” or African superplumes (hot mantle flows moving from the base of the mantle at the core of the Earth, regardless of convective currents in the mantle), located at a depth of about 2900 kilometers below the African continent .
“This geological feature should be several tens of millions of years. It stretches for thousands of kilometers, but has very distinct borders, ”the scientists say.
These dense flows exist in the boundary layerbetween the mantle and the core of the planet, and, according to some assumptions, can somehow cause disturbances in the intraterrestrial sources that generate it. But before we can find out for sure, more than a dozen large-scale scientific studies will be required.
Experts say that according to the idea of a changepoles, the beginning of this event will be the processes that take place directly in the core of the planet, however, the results of the latest research suggest that everything that happens with the magnetic field around the Earth is strongly connected with the phenomena that occur in certain areas of the boundary region between the core and the mantle. If this is true, then hardly anyone would have thought that we would be obliged to solve this complex riddle by the usual ancient ritual practiced a millennium ago. Nevertheless, scientists are not yet ready to answer the question of what does all this mean for our future.
“Now we know that these changes in magneticfield arose several times in the past. And the last of them has been observed for the past 160 years. Based on this, we can conclude that all these events are part of one whole, something more, ”the researchers say.
“But it’s too early to talk about whether these changes will really be able to lead to a change in the poles of the planet.”