The Earth’s magnetic north pole has been slowly inching its way across the Arctic for decades, but recently, its path has experienced some shifts that have stood out to scientists and those who depend on navigation systems.
This century, the magnetic north pole’s movement has suddenly shifted toward Siberia for some reason. It has raised questions about what might be behind the change and how much its motion matters.
The magnetic north pole is not to be confused with the geographic North Pole, a fixed point where the axis of the Earth and its surface meet. Magnetic north is the changing location where the magnetic field lines of the planet converge.
The field is produced by the churning of the planet’s outer core, a layer of molten nickel and iron that begins about 1,800 miles beneath the Earth’s surface.
The magnetic pole shifts over time as the core’s fluid dynamics change. This process is called the geodynamo. But now, something different is happening.
“The current behavior of magnetic north is something that we have never observed before,” said William Brown, a global geomagnetic field modeler at the British Geological Survey.
The magnetic north pole was first discovered by explorer James Clark Ross in 1831. Since then, it has shifted gradually.
Throughout the past century, its movement from Canada to Russia has sped up, increasing from about six miles per year to 31 miles per year by the 2000s. But in the last five years, its movement has slowed down to about 22 miles per year.
British and American scientists have traced this movement throughout the years. They release a new edition of the World Magnetic Model (WMM) every five years. The tool is used by GPS systems and navigation devices that map the magnetic north pole.
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The latest edition was released in December, and its location was closer to Siberia than it was five years prior. Industries like aviation, navigation, and shipping rely on magnetic fields to run smoothly, so this movement is a big deal.
GPS systems, aircraft, and military equipment track the magnetic field and depend on accurate models of magnetic north to operate correctly. When the magnetic field moves, these models need to be updated to account for the shifts.
“The more you wait to update the model, the larger the error becomes,” said Arnaud Chulliat, a senior research scientist at the University of Colorado, Boulder.
“The way the model is built, our forecast is mostly an extrapolation given our current knowledge of the Earth’s magnetic field.”
It is still unclear why the speed of the magnetic north pole changed so drastically. Some scientists believe that the shift could be influenced by changes in the strength of the magnetic field near Canada and Siberia. The field is weakening in Canada but growing stronger around Siberia.
The weakening of the magnetic field could possibly signal a geomagnetic reversal, which is when the north and south magnetic poles trade places.
Such an event is not expected to happen anytime soon. The last reversal occurred around 780,000 years ago. Researchers will continue to monitor the field and record its future movement.
