A representation of the South Atlantic Anomaly in 2025 (Image source: Finlay, C.C. et al., 2025; cropped)
Using data from ESA’s Swarm satellite constellation, scientists have discovered a growing weak spot in the Earth’s magnetic field. The weak spot is called the South Atlantic Anomaly as it is located over the South Atlantic. This data from Swarm is helping us understand more about the Earth’s complex magnetic field.
Since its launch in November 2013, Swarm has been measuring the Earth’s magnetic field. Swarm is a satellite constellation consisting of three identical satellites. It has now broken the record for the longest continuous magnetic field measurement from space.
The satellite constellation revealed new findings about the South Atlantic Anomaly. The South Atlantic Anomaly is an area where the Earth’s magnetic field is weak. Swarm has shown that there has been a steady expansion of this weak spot between 2014 and 2025. The region has grown by an area comparable in size to continental Europe.
While that weakening spot is concerning enough, Swarm revealed a region with even more rapid decline in magnetic strength. That region is located southwest of Africa. It has experienced a more rapid weakening of Earth’s magnetic field since 2020.
These Swarm data also showed areas of higher magnetic strength. While the southern hemisphere has one such area, the northern hemisphere has two — one around Canada and the other around Siberia. Over the years, though, the magnetic field over Siberia has grown even stronger while the one over Canada has weakened.
Swarm’s data is helping scientists understand the Earth’s magnetic field better. With more information, they can dig deeper to find out the cause of the changes in the field’s strength in certain areas. The Earth’s magnetic field is what protects us from cosmic radiation and charged particles from the Sun. So understanding it is crucial for space safety. These findings were published in the journal Physics of the Earth and Planetary Interiors.
Chibuike Okpara – Tech Writer – 258 articles published on Notebookcheck since 2024
I have always been fascinated by technology and digital devices my entire life and even got addicted to it. I have always marveled at the intricacy of even the simplest digital devices and systems around us. I have been writing and publishing articles online for about 6 years now, just about a year ago, I found myself lost in the marvel of smartphones and laptops we have in our hands every day. I developed a passion for learning about new devices and technologies that come with them and at some point, I asked myself, “Why not get into writing tech articles?” It is useless to say I followed up the idea — it is evident. I am an open-minded individual who derives an infinite amount of joy from researching and discovering new information, I believe there is so much to learn and such a short life to live, so I put my time to good use — learning new things. I am a ‘bookworm’ of the internet and digital devices. When I am not writing, you will find me on my devices still, I do explore and admire the beauty of nature and creatures. I am a fast learner and quickly adapt to changes, always looking forward to new adventures.