Swarm Reveals Growing Weak Spot in Earth's Magnetic Field

The South Atlantic’s Giant Weak Spot In The Earth’s Magnetic Field Is Growing

Look, we don’t really want to advertise the point of vulnerability in a key Earthly defense against invaders, but this is getting hard to miss.

Satellites reveal weak spot in Earth's magnetic field keeps growing: "There's something special happening"

The weak spot, known as the South Atlantic Anomaly, was identified in the 19th century and expanded in recent years.

Vast Anomaly in Earth's Magnetic Field Keeps Growing, Satellites Reveal

A giant dent in Earth's magnetic field is continuing to expand, according to the latest data from a trio of satellites monitoring our world.

Swarm reveals growing weak spot in Earth's magnetic field

Using 11 years of magnetic field measurements from the European Space Agency's Swarm satellite constellation, scientists have discovered that the weak region in Earth's magnetic field over the South Atlantic—known as the South Atlantic Anomaly—has expanded by an area nearly half the size of continental Europe since 2014.

Earth’s magnetic field has a weak spot that’s growing

For 11 years, the European Space Agency’s Swarm satellite constellation has been tracking shifts in Earth’s magnetic field. ESA said on October 13, 2025, that a weak spot over the South Atlantic and South America is growing and stretching toward the tip of Africa. Meanwhile, a strong spot over Siberia is increasing. Image via ESA (Data source: Finlay, C.C. et al., 2025). Earth’s magnetic field has a weak spot that’s growing Earth’s magnetic fiel…