In the last 50 years, the minimum intensity in the South Atlantic anomaly has fallen from about 24,000 to 22,000 nanoteslas,and a second center emerged in it over the past decade.
Earth’s magnetic field has lost about 9% of its strength in the last 200 years, the European Space Agency (EEA) reports.
The area where the least intensity is recorded is the so-called South Atlantic anomaly, which covers a large part of South America and extends to South Africa. Between 1970 and 2020, the minimum magnetic field intensity fell in that area from about 24,000 to 22,000 nanoteslas,the agency says.
At the same time, as noted, the area is not static. It is moving westward at a speed of 20 kilometers a year and is also growing. In fact, due to the expansion of the phenomenon, a second centre of minimum intensity has appeared in the last five years, located in southwestern Africa. Scientists now believe that the anomaly could be splitting in two, the ESA, which studies the phenomenon with the help of the Swarmmissionsatellites, launched in 2013.
The magnetic field defends our planet from the flow of electrically charged particles from space. Without him, we’d die of radiation. Thus, a 2019 study estimated that 565 million years ago the magnetosphere nearly disappeared, which could have resulted in the extinction of life on Earth.
However, the South Atlantic anomaly poses no danger on a surface level. The only way it can harm humans is if it causes technical failures in satellites and other ships flying over the area in low-Earth orbit, the ESA asserts.
It is also reported that the weakening of magnetism is within what are considered the limits of normal fluctuations. Thus, the sign of an upcoming reversal of the magnetic field, a phenomenon that occurs around every 250,000 years and temporarily deprives the Earth of protection against the solar wind, should not be considered.
In the meantime, given the importance of this phenomenon surrounded by mysteries, the agency notes that it will continue to study it.
“The new eastern minimum of the South Atlantic anomaly has been forming for a decade, although its development has accelerated in recent years. We are very lucky to have Swarm satellites to investigate the evolution of this anomaly. The challenge now is to understand the processes that in the Earth’s core cause these changes,” quotes the ESA’s statement to J. Matzka,from the German Centre for Geosciences Research (GFZ).