Scientists warn that a weakened area of Earth’s magnetic field over the South Atlantic is expanding rapidly and could cause serious satellite malfunctions, including complete shutdowns, according to a new study.
The area has expanded considerably over the past 11 years. PHOTO: NASA
Earth’s magnetic field, essential for protecting life against cosmic radiation and charged particles from the Sun, is generated by the ocean of molten iron in the planet’s outer core, about 3,000 kilometers deep. The movement of this molten iron generates electrical currents that create the Earth’s magnetic shield, but the exact mechanisms remain poorly understood, according to the study cited by The Independent.
Using measurements obtained over 11 years from three identical satellites launched in 2013, the researchers were able to precisely analyze the magnetic signals coming from inside and outside the planet. Their conclusion: The South Atlantic Anomaly – an area where the magnetic field is unusually weak – has expanded by an area equivalent to nearly half of continental Europe from its 2014 size.
“Something special happens in this region that causes the field to weaken more intensely,” explains the study’s lead author, Chris Finlay, from the Technical University of Denmark.
Researchers believe this distortion is related to abnormal patterns at the boundary between Earth’s liquid core and mantle. Instead of the magnetic field lines going out of the core, in certain areas they are going back into it – an unexpected behavior. The data also show that one of these areas is moving westward over Africa, helping to widen and intensify the anomalies.
Important changes were also observed in other regions of the planet: over Siberia, the magnetic field intensified, while it weakened in the Canadian area. These variations affect satellite navigation systems and determine the level of radiation to which satellites in low Earth orbit are exposed.
Experts warn that spacecraft and astronauts – including those on the International Space Station – passing through the South Atlantic Anomaly could be exposed to higher doses of radiation than in the past.
The study, published in the journal Physics of the Earth and Planetary Interiors, emphasizes the need for continuous monitoring of the magnetic field.
