Strange behavior in the South Atlantic magnetic field dates back to 11 million years ago, and is unlikely to be related to an impending reversal of Earth’s magnetic field, the researchers have found.
Earth’s magnetic poles, which serve as the basis for our navigation, are actively moving. The magnetic field reverses its polarity every several hundred thousand years, where the magnetic North Pole resides at the geographic South Pole. The last reversal occurred 770,000 years ago, but if a reversal occurred during our lifetime, it could affect navigation, satellites, and communications.
The area is the subject of debate among scientists, some of whom question where it comes from and whether it could indicate the total weakening of the field, and even an upcoming pole reversal.
The South Atlantic Anomaly is an area that stretches from Africa to South America, where Earth’s magnetic field gradually weakens.
Here’s the good news: In research published Monday, scientists from the University of Liverpool said they have evidence that today’s South Atlantic Anomaly is a recurring feature, and unlikely to be related to an impending reversal of the field. magnetic earth.
The researchers analyzed igneous rocks from Santa Elena Island, a small volcanic island located right in the middle of the South Atlantic and found in the South Atlantic Anomaly.
Geomagnetic rock records, which covered 34 volcanic eruptions in the area between 8 and 11 million years ago, revealed that the magnetic field for Santa Elena often pointed away from the North Pole, just as it does now.
Largely generated by an ocean of superheated liquid iron in Earth’s core, the magnetic field creates electric currents, which in turn generate our changing electromagnetic field. The field, which is not static, varies in both strength and direction, according to the European Space Agency.
“Our study provides the first long-term analysis of the magnetic field in this region that dates back millions of years,” he said. Lead author Yael Engbers, a doctoral student at the University of Liverpool, in a statement. “It reveals that the anomaly in the magnetic field in the South Atlantic is not unique; similar anomalies existed eight or 11 million years ago.”
“This is the first time that irregular behavior of the geomagnetic field in the South Atlantic region has been demonstrated on such a long time scale,” Engbers said in the statement. “It suggests that the South Atlantic Anomaly is a recurring feature and is probably not a sign of an impending reversal.
“It also supports previous studies suggesting a link between the South Atlantic Anomaly and anomalous seismic features in the lower mantle and outer core,” added Engbers. “This brings us closer to linking the behavior of the geomagnetic field directly with the characteristics of the Earth’s interior.”
CNN’s Ashley Strickland contributed to this report.
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