What Would Actually Happen In a Magnetic Pole Shift?

By the author of Be Ready for Anything and the online course Bloom Where You’re Planted

What would happen if the Earth’s magnetic poles literally flipped upside down? If north was south and south was north? Would it just be our compasses going awry or would this result in a catastrophic end for the citizens of Planet Earth? Would a pole shift be the end of humanity?

It depends on who you ask.

For example, the UK Daily Mail describes this horrific scene:

This sounds like the plot for a disaster movie: an invisible magnetic force-field that defends life on Earth against killer rays from space goes awry. Blasts of radiation destroy our satellite communications and bring the world’s electricity supplies crashing down.

Chaos reigns. Human cancer cases multiply as unshielded radiation from the sun devastates people’s DNA. Billions of creatures the world over die because their ability to migrate becomes fatally confused by changes in our planet’s magnetic field.

Ultimately, Earth’s atmosphere itself could be blown away by fierce solar winds, as happened long ago to our sister planet Mars when its magnetic field dissipated.

But hold the popcorn. This is not a sci-fi movie. Leading scientists warn that this may really happen, because of an imminent revolution at the Earth’s core. (source)

Meanwhile, Science 20 rebuts the doomsday scenario.

If we get a magnetic pole reversal, then from studies of previous reversals and modeling, the main risk is increased UV as a result of the ozone layer damaged by repeated solar storms. It would mean that you need to wear more sunblock cream on sunny days…

…The risks from solar storms are always present, whether it’s a magnetic reversal or not. The main risk of a solar storm is of GPS satellites glitching for hours, recovering once it is over – and of power cuts. We used to think that the power cuts could be severe and cost getting on for a trillion dollars and risk power cut for months or longer. 

However, the grid is more resilient than those early studies suggested. It is now thought to be similar to a major hurricane in effect, perhaps up to $100 billion in costs for the US and only local short-term power cuts…

…Some people get scared that it would lead to climate effects like ice melting at the poles, earthquakes, etc. This is a magnetic pole shift, not a geographical one. All that happens is that your compass starts to point in a different direction and eventually it points south instead of north. (source)

There are many signs that the poles are indeed going to flip.

When a pole shift occurs, it is a temporary phenomenon – it always shifts back. The problem is, we don’t know precisely when this will happen. But the signs that it is imminent are present.

Geophysicist Daniel Baker of the University of Colorado at Boulder noted that over the past 200 years the planet’s magnetic field has weakened by 15 percent, it can be a sign of the imminent geomagnetic inversion. (source)

EarthSky provides other clues about an impending shift.

What currently has geophysicists like us abuzz is the realization that the strength of Earth’s magnetic field has been decreasing for the last 160 years at an alarming rate. This collapse is centered in a huge expanse of the Southern Hemisphere, extending from Zimbabwe to Chile, known as the South Atlantic Anomaly. The magnetic field strength is so weak there that it’s a hazard for satellites that orbit above the region – the field no longer protects them from radiation which interferes with satellite electronics.

And the field is continuing to grow weaker, potentially portending even more dramatic events, including a global reversal of the magnetic poles. (source)

NASA is even more specific.

“The latest satellite data, from the European Space Agency’s Swarm trio, which began reporting in 2014, show that the battle is raging at the edge of the core.”

During the reversal, a magnetic field transforms into a weaker and more complex form. It can lose a tremendous amount of its present-day strength. Researchers claim that changes within the Earth have already weakened the field over the South Atlantic to such an extent that satellites in the region have experienced memory failure.

“The north magnetic pole is on the run, a sign of enhanced turbulence and unpredictability. A cabal in the Southern Hemisphere has already gained the upper hand over about a fifth of the Earth’s surface. A revolution is shaping up,’ reads the magazine.

“If these magnetic blocs gain enough strength and weaken the dipole, even more, they will force the north and south poles to switch places as they strive to regain supremacy. Scientists can’t say for sure that is happening now — the dipole could beat back the interlopers. But they can say that the phenomenon is intensifying and that they can’t rule out the possibility that a reversal is beginning.” (source)

When it does happen, it won’t be overnight. It could take 1000-2000 years for it to occur, which is good news. The shift would be gradual, which would give us time to adapt – and survive.

Precisely how gradual is it? According to NASA, “The magnetic north pole has been creeping northward – by more than 600 miles (1,100 km) – since the early 19th century, when explorers first located it precisely. It is moving faster now, actually, as scientists estimate the pole is migrating northward about 40 miles per year, as opposed to about 10 miles per year in the early 20th century.”

A pole shift has happened many times in the past.

Historically, pole shifts happen approximately every 200,000 years. The last pole shift was 780,000 years ago, so we’re quite overdue.

Reversals are the rule, not the exception. Earth has settled in the last 20 million years into a pattern of a pole reversal about every 200,000 to 300,000 years, although it has been more than twice that long since the last reversal. A reversal happens over hundreds or thousands of years, and it is not exactly a clean backflip. Magnetic fields morph and push and pull at one another, with multiple poles emerging at odd latitudes throughout the process. Scientists estimate reversals have happened at least hundreds of times over the past three billion years. And while reversals have happened more frequently in “recent” years, when dinosaurs walked Earth a reversal was more likely to happen only about every one million years.

Sediment cores taken from deep ocean floors can tell scientists about magnetic polarity shifts, providing a direct link between magnetic field activity and the fossil record. The Earth’s magnetic field determines the magnetization of lava as it is laid down on the ocean floor on either side of the Mid-Atlantic Rift where the North American and European continental plates are spreading apart. As the lava solidifies, it creates a record of the orientation of past magnetic fields much like a tape recorder records sound. The last time that Earth’s poles flipped in a major reversal was about 780,000 years ago, in what scientists call the Brunhes-Matuyama reversal. The fossil record shows no drastic changes in plant or animal life. Deep ocean sediment cores from this period also indicate no changes in glacial activity, based on the amount of oxygen isotopes in the cores. This is also proof that a polarity reversal would not affect the rotation axis of Earth, as the planet’s rotation axis tilt has a significant effect on climate and glaciation and any change would be evident in the glacial record. (source)

This wasn’t the only shift in our planet’s history.