Recent researches showed that the earth magnetic field is weakening dramatically. This massive disturbance is considered part of a pattern that lasts for over 1000 years.
Earth’s magnetic field is characterized by its ability to protect us from north winds and cosmic radiation, but this invisible force field is rapidly weakening, to the point scientists think it could actually flip the magnetic poles.
The region that concerns scientists the most at the moment is called the South Atlantic Anomaly – a huge expanse of the field stretching from Chile to Zimbabwe.
The field is so weak within the anomaly that it’s hazardous for Earth’s satellites to enter it, because the additional radiation it’s letting through could disrupt their electronics.
One of the reasons scientists don’t know much about the magnetic history of this region of Earth is it lacks what’s called archeomagnetic data – physical evidence of magnetism in Earth’s past, preserved in archaeological relics from bygone ages.
One such bygone age belonged to a group of ancient Africans, who lived in the Limpopo River Valley – which borders Zimbabwe, South Africa, and Botswana: regions that fall within the South Atlantic Anomaly of today.During times of drought, they would burn down their clay huts and grain bins, in a sacred cleansing rite to make the rains come again – never knowing they were performing a kind of preparatory scientific fieldwork for researchers centuries later.
“When you burn clay at very high temperatures, you actually stabilize the magnetic minerals, and when they cool from these very high temperatures, they lock in a record of the earth’s magnetic field. As such, an analysis of the ancient artifacts that survived these burnings reveals much more than just the cultural practices of the ancestors of today’s southern Africans.”
the geophysicist John Tarduno explained.”We found evidence that these anomalies in the South Atlantic have happened in the past, and this helps us contextualize the current changes in the magnetic field.”
Tarduno said. The artifacts revealed that the weakening in the South Atlantic Anomaly isn’t a standalone phenomenon of history.
“We’re getting stronger evidence that there’s something unusual about the core-mantel boundary under Africa that could be having an important impact on the global magnetic field,” Tarduno says.
The current weakening in Earth’s magnetic field which has been taking place for about 160 years is thought to be caused by a vast reservoir of dense rocks in Africa.
Source: Science Alert