The magnetic north pole just isn’t where it used to be.
Ever since James Clark Ross first identified it on the Boothia Peninsula in Canada’s Nunavut territory in 1831, scientists have been carefully measuring its location ever since. But in recent years, it’s been inching closer and closer to Siberia at a surprisingly rapid pace.
Now, researchers from U.K. and Denmark say they’ve uncovered the reason for this mysterious movement: Two writhing lobes of magnetic force are duking it out near Earth’s core.
“The wandering of Earth’s north magnetic pole, the location where the magnetic field points vertically downwards, has long been a topic of scientific fascination,” the researchers write in their paper, which appears in the May 5 issue of Nature Geoscience.
Earth’s magnetic field is generated by molten iron in its outer core. The flow of this liquid iron can influence the location of the planet’s magnetic poles. While poles have drifted and even swapped places numerous times over the course of Earth’s long history, what’s different about this recent shift is how quickly it’s happening. From 1999 to 2005, Earth’s magnetic north pole went from shifting 9 miles at most each year to as much as 37 miles in a year.