A study by scientists from the University of Liverpool, USA, revealed unusual magnetic field behavior in the South Atlantic region that took place from 8 to 11 million years ago. These findings indicate that the South Atlantic Magnetic Anomaly is a recurring phenomenon, and therefore is not an unambiguous sign of an imminent change in the planet’s magnetic poles.
The South Atlantic Anomaly is an area of the earth’s surface that is characterized by a significant decrease in the intensity of the magnetic field, in comparison with other zones located at the same geographical latitude. The level of protection against harmful cosmic radiation has been reduced here. This, in particular, is manifested in the fact that in this area there are malfunctions in the operation of technical devices on board satellites and spacecraft.
In a new study, scientists led by Yael A. Engbers analyzed paleomagnetic traces preserved in igneous rocks from Saint Helena, which lies at the center of the South Atlantic Anomaly.
The remanent magnetization of these rocks, which were ejected to the surface by 34 different volcanic eruptions that occurred between 8 and 11 million years ago, showed that during this period the direction of the Earth’s magnetic field in the vicinity of St. Helena often deviated from the direction of the northern geographic pole, just like in our days.
The Earth’s magnetic field protects our planet from charged solar particles called the solar wind and other cosmic radiation. The South Atlantic Magnetic Anomaly is a local weakening of this field, and its origin has not yet been scientifically explained. Some scientists believe that it may indicate an imminent change of magnetic poles on Earth (when the south and north magnetic poles change places). According to Engbers and her team, the confirmation of the fact of the historical recurrence of the unusual behavior of the magnetic field in the vicinity of the anomaly zone indicates that this anomaly is not associated with the approaching change of the Earth’s magnetic poles.