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Poles apart -

The North Pole and the South Pole have been getting weaker and weaker over the past one thousand years or so. But what does that mean exactly?

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Decreasing strength -

Some scientists theorize that the geomagnetic field is decreasing in strength just before it completely reverses direction—something it has done several times in the past.

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Decreasing strength -

In other words, if their magnetism continues to decay, it could trigger a pole flip, where north becomes south and south becomes north!

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Magnetic field flips -

Magnetic field flips aren't all that common. On average, they've happened around every 200,000 to 300,000 years. But the last one was 780,100 years ago, so some believe we're overdue a change.

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A temporary flip -

However, this doesn't include a temporary flip that occurred 41,000 years ago. The reversal only stuck for 250 years before switching back to the positions the poles remain in today.

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Mid-ocean ridges -

Mid-ocean ridges provide evidence of geomagnetic reversals. This is because tectonic plates of the Earth's crust (lithosphere) move apart and are filled in with magma. 

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Mid-ocean ridges -

As magma escapes, cools, and solidifies on the seabed, it imprints a record of the direction of the magnetic field at the time.

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Magnetic fields -

Magnetic fields are generated by electric charges in motion. In a bar magnet, the moving charges are electrons orbiting in atoms. In the Earth, they are electrons moved around by circulating currents of molten iron.

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Molten iron outer core -

The reason pole flips happen is still a mystery. However, scientists believe it has something to do with the molten iron outer core of the Earth.

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Molten iron outer core -

The rotation of the Earth's molten iron outer core is what generates the magnetic field. The core cools slowly and movement occurs due to convection. Imagine it like water boiling in a saucepan.

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The magnetic field -

But there's a big difference between this process and a boiling saucepan: moving charges are present that generate the magnetic field.

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Dynamo process -

This is referred to as a self-exciting dynamo process, where the electrical currents flowing in the slowly moving molten iron create a magnetic field.

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Positive feedback loop -

The magnetic field then induces electric currents. These currents in turn generate their own magnetic field which induces more electric currents, in a positive feedback loop.

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Chaos and mystery -

A lot of chaos and turbulence is generated as the molten iron core moves around. This turbulence is the most widely accepted explanation for pole reversal, but no one can say for sure at this time. It's still a mystery.

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Lines of attraction -

Magnetic poles are located where the magnetic lines of attraction enter Earth. For a polarity reversal to occur, the magnetic field needs to weaken by about 90% to a threshold level. This process can take thousands of years.

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The World Magnetic Model (WMM) -

Developed jointly by the US National Geophysical Data Center and the British Geological Survey, the World Magnetic Model (WMM) is a large spatial-scale representation of the Earth's magnetic field.

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Location -

The North Magnetic Pole, also called the North Geomagnetic Pole, is currently located near 80.8 degrees north by 72.7 degrees west, in Ellesmere Island, Canada. 

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The moving North Magnetic Pole -

In 2022 it was reported that the North Magnetic Pole was moving out of the Canadian Arctic and toward Siberia so erratically that scientists were surprised.

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The moving North Magnetic Pole -

The speed of the North Magnetic Pole's movement has increased since the mid-90s from 9 miles (15 kilometers) per year to 34 miles (55 kilometers) per year. In recent years, it has even careened over the international date line toward the Eastern Hemisphere.

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Foreshadowing? -

Does this movement foreshadow a pole flip event, alongside the decaying of the Earth's magnetic field? Only time will tell.

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Pole flipping -

The flipping of the magnetic poles doesn’t mean the Earth would no longer have a magnetic field. However, imagine that your compass would continue to point North, when you're actually facing South.

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Pole flipping -

The good news is, life has survived and thrived despite pole flips that have happened in the past. It doesn't mean global catastrophe.

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The effects of a flip -

During solar storms, there is a higher-than-normal influx of energetic particles, which are mostly harmless to us. But it's a different story for our modern-day technology.

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The effect on tech -

Charged particles from the solar wind (that our magnetic field usually protects us from), could have devastating effects on tech were a pole flip to occur. 

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The Carrington event -

In 1859, a powerful geomagnetic storm made aurorae visible in the Caribbean and telegraph systems failed. However, back then operators were capable of operating the system without power.

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Much more disruptive -

If such an event were to happen today, given our reliance on tech, it has the potential to be a lot more destructive. But it's a worst-case scenario.

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Multiple poles -

Multiple poles can also form when a reversal event takes place, confusing navigation systems. But the process can take place over hundreds, or even thousands, of years.

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Geomagnetic activity -

It's also important to note that previous pole reversals don't suggest the flip led to more volcanoes, earthquakes, or climate changes.

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Nothing to fear -

You can rest assured, while it might sound scary, a pole flip is not something you need to worry about too much. 

Sources: (NASA) (IFL Science) (NBC News) (Space.com) (Astronomy)

See also: The space war is closer than you might think

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