Earth’s magnetic field may not be flipping

Enlarge / It doesn't look like anything to me. (credit: Tom Bridgman/NASA)

Going back millions of years into Earth's history, our planet's magnetic field has frequently gone its own way. The magnetic north pole has not only wandered through the north, but it has changed places with the south magnetic pole, taking up residence in the Antarctic. Going back millions of years, there's a regular pattern of pole exchange, with flips sometimes occurring in relatively rapid succession.

In those terms, our current period of pole positioning is unusually long, with the last flip occurring nearly 800,000 years ago. But the magnetic field has grown noticeably weaker since we started measuring it more than a hundred years ago. The poles have wandered a bit, and there's an area of even more dramatic weakening over the South Atlantic. Could these be signs that we're due for another flip?

Probably not, according to new research published with the refreshingly clear title, "Earth’s magnetic field is probably not reversing." In it, an international team of researchers reconstructs the history of some past flips and argues that what's going on now doesn't much look like previous events.