Where is the North Pole?
The obvious answer, you might say – probably in an exasperated tone – is of course, in the north; the northernmost north, so to speak, where you couldn’t go any further north, exactly where Santa Claus lives.
But the answer, it turns out, is not so simple (or fanciful) – but that’s because the question itself is kind of misleading. The question isn’t “Where is the North Pole,” but rather “Where are the north poles?”
The north … poles?
That’s right, there isn’t just the one; there are actually three distinct north poles. First, there is “true north,” which is the northern end of the axis on which the Earth rotates.
Then, there is the “geomagnetic north,” which is determined by the spin of the planet’s protective magnetic bubble, or the magnetosphere. The magnetosphere’s spin is not perfectly aligned with the Earth’s spin. The northern pole of its axis sits a little off the northwest coast of Greenland.
Finally, we have the magnetic north, which is defined as the point at which magnetic field lines point vertically down. It is the direction to which all compasses point. But unlike the completely fixed true north and the almost fixed geomagnetic north, the magnetic north shifts and changes over time because of the changes in the Earth’s magnetic core. Depending on the decade, our compasses have been pointing us in different directions!
But, in 2018, scientists noticed something strange about magnetic north’s movement.
For the last century or so, the direction in which our compasses point has gradually been moving north from Greenland towards Siberia at a more or less steady pace. Every five years, scientists would update the World Magnetic Model – the standard model used for navigation by the US and UK departments of defense, NATO and all civilian GPS systems – with the latest magnetic north.
Accordingly, scientists working on the model met in 2005, 2010, 2015 – and then, unexpectedly, in an emergency session in 2019. This was because, by early 2018, scientists had realised that the model would soon exceed the acceptable limits for magnetic-based navigation – the magnetic north seemed to be galloping across the Northern Hemisphere at an unprecedented pace.
“The north magnetic pole is quite a sensitive place,” said Phil Livermore, a geophysicist at the University of Leeds. “Things are acting very strangely at high latitude.”
The World Magnetic Model had to be updated before the model’s next regular update, slated for 2020.
The magnetic tug-of-war
No one actually knows why the magnetic north has sped up its movement, but some scientists have a few plausible ideas. At the 2018 American Geophysical Union fall meeting, Livermore presented what he calls a magnetic field “tug-of-war” that may offer an explanation for the recent odd behaviour.
According to him, the magnetic north appears to be controlled by two patches of magnetic field – one under northern Canada and the other under Siberia – that are engaged in a perpetual tug-of-war. Historically, the magnetic field under Canada was stronger, but things may be changing.
“The Siberian patch looks like it’s winning the battle,” said Livermore. “It’s sort of pulling the magnetic field all the way across to its side of the geographic pole.”
This could be because of the jet stream in Earth’s liquid core that is weakening the Canadian field, but there is no scientific consensus on this.
Is the GPS still accurate, though?
Given the information we have now, the shifting of the magnetic north seems to be little more than a scientific curiosity. And no, your GPS would have been entirely reliable even if the World Magnetic model wasn’t updated in time – as long as you weren’t using it in the Arctic region!
As for predicting the magnetic north’s movements in the future – “We don’t have any idea,” said Geoff Reeves, a space scientist at Los Alamos National Lab. “What we know is what it’s doing now is different, and that’s always exciting scientifically.”
Did you know the Earth has three north poles? How often do you use the GPS, and what would you do if the magnetic north rendered it useless? Type out your answers in the comments below!