![\"South](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2025\/10\/72670a3dfb80d4d32b32be2bd5213251.jpeg\"\/)
<\/p>\nMore than a decade of satellite monitoring has mapped Earth\u2019s magnetic field as it subtly altered between 2014 and 2025 \u2014 and what scientists have learned is remarkable. The South Atlantic Anomaly, a weak region, is expanding, the north magnetic pole is moving towards Siberia, and the unseen shield that protects life against solar and cosmic radiation is evolving at a rate never recorded before.<\/p>\n
After a Global Force<\/p>\n
The Earth\u2019s magnetic field is similar to a huge, constantly changing bubble that shields the planet by deflecting charged particles and radiation from the Sun. It\u2019s created far below our feet in a sea of molten iron that churns around in the outer core some 1,800 miles down. When the liquid metal moves, electric currents result, which produce the magnetic field.<\/p>\n
Since 2013, the European Space Agency\u2019s Swarm mission \u2014 a trio of satellites known by the nicknames Alpha, Bravo, and Charlie \u2014 has been tracking this hidden force with greater precision than ever before. Each of the three spacecraft tracks both direction and magnitude of the magnetic field enveloping the planet, helping scientists to break down signals that reach not only from the core but also from the crust, oceans, ionosphere, and magnetosphere.<\/p>\n
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South Atlantic Anomaly 2025 compared to 2014. (CREDIT: ESA (Data source: Finlay, C.C. et al., 2025))<\/p>\n
Through employing only Swarm data and not combining several satellite sources, scientists ensured the record to be reliable in space and time. Their research builds an uninterrupted image of the manner in which the Earth\u2019s core<\/a> field evolved over the past eleven years.<\/p>\n The Expanding Weak Zone<\/p>\n One of the research\u2019s most astonishing discoveries is above the South Atlantic Ocean. There, in the region called the South Atlantic Anomaly, the magnetic field is unusually weak \u2014 a region where satellites can be hit with excess radiation that occasionally leads to failures or even temporary shutdowns.<\/p>\n Since 2014, the region of weak field has grown by nearly two million square miles \u2014 about half the size of continental Europe. The weakest field throughout the region has dropped over 330 nanoteslas, and the affected region now covers nearly one percent of Earth\u2019s surface.<\/p>\n Chris Finlay, professor of geomagnetism at Denmark\u2019s Technical University<\/a> and senior author of the study, states that the South Atlantic Anomaly is not a single unit. \u201cIt\u2019s changing differently towards Africa than it is near South America,\u201d he says. \u201cThere\u2019s something strange going on in this region that\u2019s causing the field to reduce in a more deeper way.\u201d.<\/p>\n Swarm is ESA\u2019s first constellation of Earth observation satellites designed to measure the magnetic signals from Earth\u2019s core, mantle, crust, oceans, ionosphere and magnetosphere, providing data that will allow scientists to study the complexities of our protective magnetic field. (CREDIT: ESA\/AOES Medialab)<\/p>\n Underlying that area, Swarm\u2019s measurements show enigmatic \u201creverse flux patches\u201d where magnetic field lines abruptly dip back into Earth\u2019s interior instead of bending outward. A reversed zone has migrated westward under Africa in recent years, likely fueling the current decline in field strength there.<\/p>\n A Tug-of-War in the North<\/p>\n Whereas the South Atlantic is weakening, a drama is being enacted in the Northern Hemisphere. Two strong magnetic regions<\/a> \u2014 one located over Canada and the other over Siberia \u2014 are engaged in what scientists call a magnetic tug-of-war.<\/p>\n During the last decade, the Canadian sector has lost strength and diminished by approximately 0.65 percent of Earth\u2019s surface area \u2014 approximately India\u2019s size. The Siberian sector, on the other hand, has gained power by approximately 0.42 percent, an area roughly the size of Greenland. The changing balance goes some way to explaining why the North Magnetic Pole has been moving so swiftly towards Siberia in recent years.<\/p>\n When you\u2019re trying to understand Earth\u2019s magnetic field, you should know it\u2019s not a simple bar magnet,\u201d Finlay added. \u201cIt\u2019s only with the satellites like Swarm that we can get an idea of how dynamic and complex it is.\u201d<\/p>\n Changes in strong magnetic field over Canada and Siberia. (CREDIT: ESA (Data source: Finlay, C.C. et al., 2025))<\/p>\n Peering Beneath the Surface<\/p>\n To observe why these transformations appear as they do on the surface, researchers looked deeper \u2014 to the boundary between Earth\u2019s outer liquid core and solid mantle, around 1,800 miles beneath the earth\u2019s surface. There, massive currents of molten iron generate magnetic patterns that change and evolve with time.<\/p>\n From 2014 to 2025, the big magnetic features under Africa moved west, and the ones under Siberia and Alaska moved south and west. Some of them got stronger, some of them got weaker. These deep movements ripple out and slowly alter the magnetic field<\/a> we sense near the surface.<\/p>\n The Swarm data show that nearly all of the variation you can quantify at Earth\u2019s surface \u2014 more than 99 percent of it \u2014 can be explained by core-scale motion. They are driven by powerful buoyancy forces, rotation, and magnetohydrodynamic waves that churn in the liquid metal.<\/p>\n Why It Matters<\/p>\n Changes in Earth\u2019s magnetic field can be far-reaching, although they appear unreal. Compasses and navigation devices depend on it. Satellites exposed to more radiation in regions where the field is weak can become infested with bugs or even be irreparably damaged. Even space travelers in orbit around our planet depend on this magnetic shield for protection against nasty solar storms.<\/p>\n Magnetic Field Intensity (F) at Earth\u2019s surface in the northern polar region (a) in Epoch 2014.0 and (b) in Epoch 2025.0. Units are nanoTesla (nT) Presented in an Azimuthal Nearside Perspective projection. (CREDIT: Physics of the Earth and Planetary Interiors)<\/p>\n South Atlantic Anomaly is already known to space organizations as a threat. Spacecraft passing over the region are more likely to be corrupted with data or experience equipment failure, leading to radiation-hardened equipment being designed and shutdown planning when crossing the zone.<\/p>\n The Mission That Keeps Watching<\/p>\n ESA\u2019s Swarm mission<\/a>, which began in late 2013 within the agency\u2019s FutureEO programme, was planned for four years but remains active. The satellites currently offer the longest continuous record of magnetic field measurements ever made from space.<\/p>\n Due to the long timeseries of Swarm, we can actually see the big picture of our dynamic planet,\u201d said ESA\u2019s Swarm Mission Manager Anja Stromme. \u201cThe satellites are all healthy and providing us with excellent data, so hopefully we can keep this record going way beyond 2030.\u201d.<\/p>\n Scientists will employ the growing Swarm data to more rigorously test computer models known as geodynamo models \u2014 digital replicas of the molten core\u2019s movement. They may eventually forecast how the field will evolve decades in the future, as meteorologists forecast the atmosphere.<\/p>\n Evolution of the South Atlantic weak field region in terms of the area contained within contours of magnetic field Intensity (F) at Earth\u2019s surface between 2014.0 and 2025.0. (CREDIT: Physics of the Earth and Planetary Interiors)<\/p>\n Practical Implications of the Research<\/p>\n An improved knowledge of the alteration of Earth\u2019s magnetic field will better protect satellites, power lines, and navigation systems that rely on magnetic data. Monitoring weaknesses like the South Atlantic Anomaly might lead to more efficient spacecraft construction<\/a> and safer flights into space.<\/p>\n For scientists, these findings give them a broader view into the hidden machinery of Earth\u2019s interior.<\/p>\n By comparing Swarm\u2019s magnetic recording with computer simulations of fluid-dynamics, researchers can uncover how liquid iron flows within the core \u2014 and how that movement drives the magnetic field that sustains life on Earth.<\/p>\n Research findings are available online in the journal Physics of the Earth and Planetary Interiors<\/a>.<\/p>\n Related Stories<\/p>\n![\"Swarm](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2025\/10\/1e1b852e4a9e7360a6ff814a5555aa06.jpeg\"\/)
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