Over the past 40 years the north magnetic pole has been drifting northwest from Canada to Siberia at the rate of 50 kilometres a year.
The pole’s recent speed up is just one of a number of anomalies that have unexpectedly thrown the world’s magnetic field map slightly out of whack and prompted an earlier-than-scheduled update, which is currently delayed by the US Government shutdown.
That might sound dramatic, but it’s not going to send anyone using modern navigation systems into a spin because GPS doesn’t rely on the magnetic field, said geophysicist Louis Moresi of the University of Melbourne.
“It’s only going to cause trouble for people who use compasses to navigate around. Even then most of them are used to making corrections,” Professor Moresi said.
“The old navigators would be a bit wise to this.”
It also isn’t a sign the magnetic field — the big bubble of magnetism that helps protects us from cosmic rays — is weakening or the poles are about to flip.
“It doesn’t tell you there’s anything weird happening, it’s a natural process,” Professor Moresi said. European explorers embarked on gruelling expeditions in the 19th century in search of the magnetic poles.
James Clark Ross reached the north magnetic pole in 1831. Roald Amundsen found the pole again in a different spot in 1903. Ernest Shackleton claimed to locate the south magnetic pole in 1909, but the location was disputed.
But both poles have moved on since then.
While the north magnetic pole has made a beeline across the International Date Line towards Siberia over the past 119 years, the south magnetic pole has moved 580 kilometres and now sits 220 kilometres off the coast of Antarctica in the Australian economic zone.
The reason for the wandering is because the Earth’s magnetic field isn’t based around a perfect bar magnet stuck through the Earth’s core. Instead, it’s created by a layer of molten iron in the Earth’s outer core, which is constantly moving.
As a result, the magnetic poles also move. And they do it independently of each other — which bizarrely means the north and south poles aren’t even directly opposite each other.