It’s time to recalibrate the navigation systems of ships, planes and (depending on the time of year) Santa’s sleigh: the position of the magnetic North Pole is officially changed, continuing its shift from Canada to Siberia.
Experts from the US National Oceanic and Atmospheric Administration (NOAA) and the British Geological Survey (BGS) have joined forces – as they do every five years – to produce a new global magnetic model (WMM) more precise.
While the geographic North Pole remains fixed (at the top of the Earth’s axis of rotation), the WMM locates the magnetic North Pole – where the Earth’s magnetic field points downward, a perfectly vertical magnetic field.
And as the iron and nickel inside our planet changes, so does Earth’s magnetic field, meaning the North (and South) poles are also constantly in motion. If you use a compass or GPS system, it is crucial to know exactly where these points are.
“The current behavior of magnetic north is something we have never observed before,” says BGS global geomagnetic field modeler William Brown.
“Magnetic north has been moving slowly around Canada since the 1500s, but over the past 20 years it has accelerated toward Siberia, increasing its speed each year until about five years ago, when it suddenly decelerated from 50 to 35 kilometers. [31 to 22 miles] per year, which represents the largest deceleration in speed we have ever seen. »
Research suggests that two giant magnetic lobes – one under Canada and one under Siberia – are causing the magnetic north to shift. Sometimes the changes are dramatic enough that an emergency update is necessary, outside of the usual 5-year cycle.
We now have a more accurate map of magnetic north, which should be valid for another half-decade. For the first time, a higher resolution map is also available, which offers more than 10 times more detail: it has a spatial resolution of around 300 km at the equator, compared to the standard 3,300 km.
According to the BGS team, driving 8,500 km (5,282 miles) from South Africa to the UK in a straight line would leave you with 150 km (93 miles) of road at the end, if you used the old WMM by report to the new WMM for your navigation.
That’s how much of a difference this can make, and mapping and logistics companies, as well as governments and official agencies, will now be making updates.
However, we won’t need to apply any updates to our own phones or navigation systems – everything will happen automatically.
The magnetic North Pole was first discovered by Sir James Clark Ross in northern Canada in 1831.
Since then, researchers have gradually been able to follow it with more precision, thanks to ground measurements taken around the world as well as satellite readings in space.