Current Readings
What Is This?
The South Atlantic Anomaly is a region where Earth's magnetic field is dramatically weaker than normal. It stretches from South America to Africa and has been growing since at least 2014.
ESA's Swarm satellites measured 11 years of continuous data revealing the anomaly has expanded by nearly half the size of Europe. The weakening accelerated after 2020.
Beneath the anomaly, reversed magnetic flux goes back into the core instead of out — linked to the African LLSVP, a mysterious super-hot blob outside Earth's core.
Satellites crossing the SAA experience increased radiation exposure, causing malfunctions, data corruption, and elevated risks for astronauts aboard the ISS.
Key Facts
• Field threshold: <26,000 nT defines the anomaly boundary
• Minimum field: 22,094 nT (2025) — down 336 nT since 2014
• Westward drift: ~0.3–0.6°/year
• The ISS passes through the SAA ~15 times per day
• Hubble Space Telescope cannot take observations during SAA passes
• Not a sign of imminent pole reversal — likely a decade-to-century fluctuation