Earth’s magnetic poles aren’t set in stone (or ice). Over the past centuries, Earth’s magnetic north has been drifting east at an accelerating pace, shifting thousands of kilometers across the globe. The massive, compass-wobbling trend is being driven by vast oceans of liquid metal in Earth’s interior and some fundamental principles of electromagnetism.
Since the 1830s, the north magnetic pole of Earth has relocated some 2,250 kilometers (1,400 miles) across the upper stretches of the Northern Hemisphere from Canada towards Siberia.
The magnetic north pole’s travel seems to be accelerating too. Between 1990 and 2005, the rate of pole movement increased from less than 15 kilometers (9.3 miles) per year to around 50 to 60 kilometers (31 to 37 miles) per year, according to a 2020 study.
If it continues at this pace, the north magnetic pole will travel up to 660 kilometers (410 miles) toward Siberia over the next decade. The effect is so profound that scientists at the British Geological Survey (BGS) have previously said that all compasses will “probably point eastward of true north” by 2040.
On the other side of the planet, Earth’s south magnetic pole also appears to be on the move, drifting eastwards over Antarctica’s coast. These changes may seem extreme, but bigger shifts are possible. Every 300,000 years or so on average, Earth’s magnetic poles swap entirely; the north pole is transformed into the south pole and the south pole becomes the north pole. Since the last pole swap was 780,000 years ago, some think we’re long overdue for a switch-up.
Earth’s magnetic poles are the result of molten iron and nickel sloshing around its outer core. These liquid metals are conductive and in constant motion due to the planet’s rotation and heat-driven convection. In tune with the principles of electromagnetism, the movement creates electric currents, which generate a magnetic field.
This is known as Earth’s geodynamo system or the dynamo theory. As we’ve seen in recent shifts, the magnetic poles aren’t constant and the geodynamo system can appear fairly chaotic.
As explained by the 2020 study mentioned above, the recent shift towards Siberia is possibly caused by a change in the pattern of flow in Earth’s interior that occurred between 1970 and 1999. The change resulted in the Canadian “blob” becoming elongated and losing its influence on the magnetosphere, causing the pole to slip toward Siberia.
At least, that’s one current theory.
“We know there are irregular changes in the planet’s liquid outer core and that the magnetic field is also weakening under Canada, but it’s not yet possible to say exactly for sure why magnetic north is changing so fast,” Ciarán Beggan, BGS Geophysicist, said in a 2019 statement.
The shifting pole will have minimal impact on your day-to-day life (unless you’re a pre-modern sailor navigating unchartered seas). However, scientists must keep an eye on its movement as the Global Positioning System (GPS) and other satellite-based radio navigation systems will need to be recalibrated with the shift in mind.
Source Link: Why Is Earth's Magnetic North Pole Moving Eastwards Across The Globe?
