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We are all familiar with the North Pole. Its characteristic features include the frozen sea, polar bears, the northern lights, and the midnight sun.
But did you know that the definition of the North Pole is not so simple? And in fact, there is more than one North Pole.
According to British climate scientist and explorer Felicity Aston, “There are many North Poles on Earth.”
She told the BBC podcast ‘The Infinite Monkey Cage,’ “There are two types of North Poles we can define: the magnetic North Pole and the geographic North Pole.”
Geographic North Pole
According to Aston, the one most people think of as the North Pole—the true one—is the geographic North Pole.
Imagine Earth as a slightly tilted sphere. A hypothetical rod passing from top to bottom through the center forms the axis on which the Earth rotates.
Where this imaginary axis intersects the surface is the geographic North Pole. It lies over the Arctic Ocean’s waters and ice. Directly opposite this point is the South Pole, located in Antarctica.
The geographic North Pole is located at exactly 90 degrees north latitude, where all lines of longitude converge, Aston explains.
Unlike the magnetic North Pole, this point does not shift.
Magnetic North Pole
Earth is surrounded by a magnetic field generated by electric currents in its liquid metal outer core. This field protects us from solar wind and radiation.
Like a bar magnet, Earth has two magnetic poles: one near the northern hemisphere and one near the southern hemisphere.
The Earth’s magnetic field lines form a pattern similar to those around a bar magnet. These magnetic lines indicate the direction and strength of the field.
The magnetic North Pole is the point where the magnetic field points vertically downward. A compass needle aligns toward this magnetic north.
However, due to the fluid motion of Earth’s outer layer of liquid metals, the magnetic field—and thus the magnetic North Pole—shifts over time.
“For many years it was drifting near Queen Elizabeth Islands in northern Canada,” Aston states. “In the last decade it has increased its speed.”
Until 2019, a European space agency estimated its movement as about 50 to 60 kilometers per year.
Aston says the magnetic North Pole has now moved from Canada towards Siberia’s coast.
Occasionally, the locations of the North and South Poles may swap in a process known as geomagnetic reversal.
Ancient magnetic records suggest this has happened hundreds of times over the last 160 million years, with the most recent reversal about 780,000 years ago.
Other North Poles
Other definitions of the North Pole exist but are less well-known and sometimes debated compared to the magnetic and geographic ones.
Among them is the geomagnetic North Pole, which differs from the geographic North Pole.
The magnetic North Pole is based on Earth’s actual magnetic field, whereas the geomagnetic North Pole is a theoretical location derived from a simplified model of the Earth’s magnetic field.
“It’s a kind of theoretical North Pole where Earth looks like a perfect, uniformly magnetized bar magnet,” Aston explains.
Many computer models use the geomagnetic North Pole as a reference point.
Image source, Dean Conger/Corbis via Getty Images
Then there is the cold North Pole and the inaccessible or unreachable North Pole.
The coldest inhabited place on Earth is Oymyakon, Northeast Siberia, regarded as the coldest settlement near the North Pole.
The inaccessible North Pole is located in the Arctic Ocean and is the point furthest from any land, unreachable from all directions.
There is also the astronomical North Pole used in astronomy.
This is a hypothetical point in the northern sky where Earth’s rotation axis aligns directly with space. It lies directly above the geographic North Pole and close to the pole star, Polaris.
Image source, Neil Benison via Getty Images
“If you think of the sky as a spherical field spinning around the Earth, then projecting this astronomical axis from the equator to Earth’s surface creates what some call another North Pole on the surface,” Aston says.
Methods for Finding the North Pole
Although there are many types of North Poles, theoretically locating them is not very difficult. However, reaching them and pinpointing exact positions can be challenging.
“The last time I skied to the geographic North Pole, a helicopter dropped me about 80 kilometers from the frozen surface of the Arctic Ocean, and then I had to find my own way,” Aston recalls. “All directions look the same.”
“So what do you do in that situation? Use a compass?” she asks.
Image source, Hulton Archive via Getty Images
However, compasses point not to the geographic North Pole, but toward the magnetic North Pole.
But there is a solution. One can use the angle called “declination”, which is the difference between geographic north and the direction a compass needle points. According to Aston, declination “varies depending on your location.”
“If the ice beneath you moves irregularly, it complicates this process further. Ice doesn’t always move in the same direction or velocity,” she adds.
In such cases, GPS is another option.
However, GPS devices rely primarily on batteries which drain quickly in cold weather, so full dependence on them is not recommended.
Older navigation tools like the sextant depend on sunlight and become difficult to use when cloudy, Aston explains.
“There are many methods to locate the North Pole, each with its weaknesses. So ultimately, you combine methods,” she says.
“It also involves a bit of estimation and guesswork.”
Additional reporting by Daisy Stevens from a segment of The Infinite Monkey Cage.
