Swarm probes weakening of Earth’s magnetic field

In an area stretching from Africa to South America, Earth’s magnetic field is gradually weakening.

A large region of reduced magnetic intensity has developed between Africa and South America and is known as the South Atlantic Anomaly.

Over the past five years, a second centre of minimum intensity has emerged southwest of Africa – indicating that the South Atlantic Anomaly could split up into two separate cells.

However, the growth of the South Atlantic Anomaly indicates that the processes involved in generating the field are far more complex.

Jürgen Matzka, from the German Research Centre for Geosciences, says, “The new, eastern minimum of the South Atlantic Anomaly has appeared over the last decade and in recent years is developing vigorously.

It has been speculated whether the current weakening of the field is a sign that Earth is heading for an eminent pole reversal – in which the north and south magnetic poles switch places.