Interesting: ‘Over the last 200 years, the globally averaged magnetic field has lost around 9% of its strength, with the South Atlantic Anomaly leading the way.’

May 26, 2020: New data from Europe’s Swarm satellites show something strange is afoot in Earth’s magnetic field. The South Atlantic Anomaly might be splitting in two. “A new, eastern minimum of the South Atlantic Anomaly has appeared over the last decade,” says Jürgen Matzka, from the German Research Center for Geosciences. “In recent years it has been developing vigorously.”

The South Atlantic Anomaly is a weak spot in Earth’s magnetic field centered roughly on the Atlantic side of South America. Discovered in 1958, it has been growing and shifting for decades. The latest data from Swarm show a new weak spot forming just off the southern tip of Africa.

“We are very lucky to have the Swarm satellites in orbit to investigate this development,” says Matzka.

Launched in November 2013, Swarm is a constellation of 3 identical satellites flying in formation around Earth. They are equipped with magnetometers, star…