![\"Earth's](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/10\/earths-magnetic-field-caused-emergence-of-complex-creatures-credit-nasa-goddard-space-flight-center-.jpeg\")
Earth\u2019s Magnetic Field. Credit: NASA Goddard Space Flight Center \/ Flickr \/ CC BY 2.0<\/p>\nEarth\u2019s Magnetic Field. Credit: NASA Goddard Space Flight Center \/ Flickr \/ CC BY 2.0<\/p>\n
A weak zone in Earth\u2019s magnetic field, known as the South Atlantic Anomaly, has expanded at an alarming rate over the past decade, scientists say. Using 11 years of data from the European Space Agency\u2019s Swarm satellite mission, researchers found that the anomaly has grown by an area nearly half the size of continental Europe since 2014.<\/p>\n
The South Atlantic Anomaly is a region where the planet\u2019s magnetic field is unusually weak, stretching from South America to southern Africa. The magnetic field<\/a> acts as Earth\u2019s invisible shield, deflecting harmful cosmic rays and charged particles from the Sun.<\/p>\n As this shield weakens, more radiation penetrates the atmosphere, raising concerns for satellites and spacecraft operating above the region.<\/p>\n Uneven weakening raises new scientific concerns<\/p>\n \u201cThe South Atlantic Anomaly is not just a single block,\u201d said Chris Finlay, lead author of the new study and Professor of Geomagnetism at the Technical University of Denmark. \u201cIt\u2019s changing differently towards Africa than it is near South America. There\u2019s something special happening in this region that is causing the field to weaken in a more intense way.\u201d<\/p>\n The findings, published this month in Physics of the Earth and Planetary Interiors, show that the anomaly expanded steadily between 2014 and 2025. A section of the Atlantic Ocean southwest of Africa has seen an even faster drop in magnetic strength since 2020. This uneven weakening points to complex forces deep within Earth.<\/p>\n Strange magnetic behavior deep beneath the surface<\/p>\n Researchers trace these changes to the planet\u2019s liquid outer core\u2014an ocean of molten iron about 3,000 kilometers beneath the surface.<\/p>\n The movement of this metal generates electrical currents, which produce the magnetic field that surrounds and protects the planet.<\/a> However, under the South Atlantic, scientists have detected unusual magnetic behavior known as \u201creverse flux patches,\u201d where field lines loop back into the core instead of flowing outward.<\/p>\n Warning: The South Atlantic Anomaly has expanded by an area nearly half the size of continental Europe since 2014.<\/p>\n \u2014<\/p>\n Using 11 years of magnetic field measurements from the European Space Agency\u2019s Swarm satellite constellation, scientists have discovered that the weak region in\u2026 pic.twitter.com\/HFJE6jq2Cg<\/a><\/p>\n \u2014 Brian Roemmele (@BrianRoemmele) October 14, 2025<\/a><\/p>\n \u201cNormally we\u2019d expect to see magnetic field lines coming out of the core in the southern hemisphere,\u201d Finlay explained. \u201cBut beneath the South Atlantic Anomaly we see unexpected areas where the magnetic field, instead of coming out of the core, goes back into the core. Thanks to the Swarm data we can see one of these areas moving westward over Africa, which contributes to the weakening of the South Atlantic Anomaly in this region.\u201d<\/p>\n Swarm mission delivers unprecedented long-term data<\/p>\n The Swarm mission,<\/a> launched in 2013 under ESA\u2019s Earth Observation FutureEO program, consists of three identical satellites that measure magnetic signals from Earth\u2019s core, crust, oceans, and atmosphere.<\/p>\n The mission has now produced the longest continuous record of magnetic field data from space, giving scientists a clearer view of how the planet\u2019s magnetic forces evolve.<\/p>\n ESA\u2019s Swarm Mission Manager, Anja Str\u00f8mme, said the satellites remain in excellent condition. \u201cIt\u2019s really wonderful to see the big picture of our dynamic Earth thanks to Swarm\u2019s extended timeseries,\u201d she said. \u201cWe can hopefully extend that record beyond 2030, when the solar minimum will allow more unprecedented insights into our planet.\u201d<\/p>\n Risks for satellites and space technology<\/p>\n Scientists say the South Atlantic Anomaly\u2019s ongoing expansion highlights how dynamic\u2014and unpredictable\u2014Earth\u2019s magnetic field can be. While there is no immediate danger to life on the surface, the anomaly poses growing risks for satellites,<\/a> navigation systems, and other space technologies that depend on the planet\u2019s magnetic protection.<\/p>\n