Exposing PseudoAstronomy

January 29, 2009

Planet X and 2012: The Pole Shift (Magnetic) Explained and Debunked


Continuing my series on Planet X and 2012, one of the main claims of what will actually happen is termed a “Pole Shift.” Sounds scary, huh? The Earth’s pole(s) … shifting!?

But what does it actually mean? Well, Earth actually has two sets of North and South Poles – the geographic and the magnetic. Most of the doomsdayers that I’ve heard seem to imply that they are talking about a geographic pole shift, but some also talk about a magnetic pole shift. Since both are completely different, and since they are significant enough topics by themselves, I am doing separate posts on them. This one addresses the magnetic pole.

All posts in this series:

Earth’s Magnetic Field

Most people have either seen in-person or in video a crane in a junkyard that, instead of a hook at one end, has a large metal plate. They have then seen that metal plate “activated” by something, and it becomes a strong magnet – strong enough to lift multi-ton cars. What you have just witnessed is called an “induced magnetic field.”

Induced magnetic fields are created by electricity moving in circles. It’s the principle behind all electromagnets (most medical imaging today relies upon it) and electric motors. It’s also what our planet’s magnetic field is created by.

Earth’s magnetic field is called a “magnetic dynamo” because it is produced by liquid metals moving around in Earth’s core. As these metals move, they induce currents, which create magnetic fields. Since the planet has a net rotation in one direction, the created magnetic field is built up and roughly aligned with that axis of rotation.

Earth’s magnetic field is in the form of a “dipole,” meaning that it has a “North” and “South,” or “positive” and “negative” side to it, much like a bar magnet. The field breaches Earth’s surface at the south magnetic pole, extends into space in what is known as the “magnetosphere,” and dives back into Earth at the north magnetic pole, as illustrated in the figure on the right.

Polar Wander

In 2001, Earth’s north magnetic pole was at coordinates 81.3° N by 110.8° W. But in 2004, three years later, it had moved to 82.3° N by 113.4° W. And a year later, in 2005, it was at 82.7° N by 114.4° W. Similarly, the south magnetic pole shifted, as well.

But, how could that happen? Earth’s magnetic field should be stationary, just like the geographic poles, right? Isn’t this evidence of something catastrophic happening?

In a word: No.

Earth’s magnetic poles appear to wander throughout time, and not just due to the continents drifting. “Polar wander” refers to it moving, while “true polar wander” refers to it moving relative to a fixed coordinate system that takes the continents’ movement into account. The field strength also is not constant with time, varying by location and by year. It also varies on much longer timescales, flipping over entirely (north becoming south and vice versa). The last time it flipped occurred approximately 780,000 years ago. (Evidence for this is found in the magnetic field of relatively fresh ocean crust, among other places.)

It is unknown at this time what causes Earth’s magnetic field to wander, vary, and occasionally flip. Modeling the field is very difficult, and all of the physics of it is not yet understood. The oft-portrayed simple magnetic field, as shown in the diagram above, is not correct. The field is much more complex, and it was featured in NASA’s Astronomy Picture of the Day in November of 2002, shown on the right. The magnetic field lines are a tangled mess and only when you average over them to you get the dipole magnet that most of us are familiar with.

What Happens When the Field Shifts?

Nothing of importance. As I explained in the above section, Earth’s magnetic field has been shifting at a rate of over 1° per year for many years, with data going back well over a century. And, alas for the doomsdayers, nothing bad has happened.

What Happens When the Field Flips?

This scenario – which we are almost certain will happen again since it has happened many many times in geologic history – is a little more dangerous, but that is mostly because we are an electronic society.

In terms of humans and biology, again, nothing of importance will happen. The magnetic field is relatively weak, and if you go in for an MRI you are exposed to fields many orders of magnitude larger than Earth’s. And nothing bad happens unless you’re wearing metal. Birds may be a little confused, but they existed prior to the reversal 780,000 years ago and seem to have gotten through it just fine, as anyone who lives in a city and deals with pigeons on a daily basis can attest.

In terms of what would happen to the field, it would not just shut off one day and then come back the next in the opposite direction. It won’t shut off at all. It will decrease in its strength while more magnetic field lines in the north start to turn “south,” and more in the south start to turn “north.” When more than half are the opposite of what they were, then the net effect will be that the field has flipped over.

So what will happen to us in a decreased magnetic field? Well, the main problem is that the magnetosphere will shrink. This “protective bubble” that shields us from the sun’s streaming charged particles will no longer extend as far into space. So, very high-orbit satellites will be exposed to more radiation, and consequently they will be more prone to failure, especially during any burst of solar activity, unless we have developed better ways to shield their electronics. Similarly, a burst of solar activity can induce magnetic fields in power lines (and railroad tracks) on Earth, causing surges that can short out the grid. This can (and likely will, as it already has in the past) cause blackouts, as happened in 1989 in Canada.

Does this mean the end of the world? No. It means we need to upgrade our power distribution systems around the world and keep them updated as opposed to how they’ve been languishing for decades. In fact, just today (January 28, 2009), the American Society of Civil Engineers released their 2009 annual report card, giving the US’s energy infrastructure a “D+” (the average grade was a “D”). They state:

Progress has been made in grid reinforcement since 2005 and substantial investment in generation, transmission and distribution is expected over the next two decades. Demand for electricity has grown by 25% since 1990. Public and government opposition and difficulty in the permitting processes are restricting much needed modernization. Projected electric utility investment needs could be as much as $1.5 trillion by 2030.

Now, contrast what I’ve explained the effects would be with what doomsday folks are saying, such as this article:

“As the shift approaches, things begin to go out of balance, and the magnetic field begins to fluctuate significantly over a very short period of time (about 3 – 6 months). This would be like a full moon getting bigger and bigger every day. What happens then is that people start to go crazy emotionally. This breaks down economical and social structures on the planet because it is only people who keep these structures together.”

A very quick analysis shows: We’ve got a false analogy (magnetic field changing has nothing to do and is nothing like the moon changing size), an assumed effect without any causation, and then a reducio ad absurdum when they just take the assumed effect to extreme levels.

What Would Cause This Magnetic Pole Shift That You’ve Said Won’t Happen in 2012?

Good question. The mechanisms proposed – that I’ve heard and read about – really amount to nothing but misunderstandings, numerology, or conjecture founded in superstition. They include: Earth’s rotation switching directions, Earth getting whopped by an asteroid, The sun’s magnetic field flipping ours, Planet X (Planet X seems to be able to do anything, as I’ll talk about in future posts), and some various mystical things.

I wish I could state, “needless to say, these (a) won’t happen and (b) even if they did can’t flip our magnetic field.” I can still say it if I chop off the “needless” part. The fact that when I just did a Google search to try to find folks’ mechanisms for this the first few pages were nearly all doomsday pages should tell you that these are very popular ideas in popular culture. So, I really do need to say: “These (a) won’t happen and (b) even if they did can’t flip our magnetic field.”

Without addressing each individual claim, I will broadly address the two categories of claims – a large external physical force, or a large external magnetic force. The basic reason why neither of these will happen in 2012 is that there is nothing that we know of that has enough force to affect Earth’s field on a global scale. Let’s say, for example, we get hit by an asteroid. An asteroid that’s huge – 100 km in radius (all of which have known been identified and have known orbits). Assuming the asteroid is the densest and heaviest – an iron-nickel asteroid (a composition which only 10% of asteroids are) – then it would have a mass of about 4.2·1015 kg. That’s a lot. But Earth has a mass that is 6.0·1024 kg … over 109 times more. It would be like a grain of dust hitting a car. NOTHING will happen to the Earth as a whole. Yes, it would be bad for us and for life, but the planet really wouldn’t care. Now, if another planet were to hit us, then Earth would be in trouble.

So what about a large external magnetic force? There’s nothing large enough that’s nearby. Sure, if we were to pass by a magnetar, we’ll be in trouble. Those have magnetic fields on the order of ~1015 times stronger than Earth’s. But the sun’s magnetic field really shows no evidence of affecting ours to the point of flipping it. There is no evidence at all – historic or validated theoretical – to show that the sun’s magnetic field, which is only up to ~10x stronger than Earth’s, can flip ours. After all, if it could, then it would every 11 years, since that’s how often the sun’s field flips.

So I’ve now given two ways that this really could happen – if a planet-mass object or an extraordinarily large magnetic field were to hit us or come near us, that could affect Earth’s rotation or magnetic field to the point where we would get a magnetic pole reversal (or, I guess a really big “shift”). However, we now again get to the question of evidence: There is none. We would know of a planet-sized (or larger) object that is close enough to come near us in 4 years (the end of 2012), or even 40 years. You can read my post on the Real Planet X for more information on that. Similarly, we would see effects of a gigantic magnetic field nearby that’s close enough to affect us in the near future, something we also do not see any evidence for.

Final Thoughts

Despite this post being over 1800 words – another long one – I still feel as though I’ve only scratched the surface of this topic. That’s mainly because there are nearly as many variations of what’s “predicted” to happen with the magnetic pole shift as there are people making the predictions. In this post, I’ve tried more to focus on the background information – the state of the science – and then point out why many of the main predictions are not correct nor feasible when confronted with what we can actually observe. It’s impossible to get into every single claim because more crop up as soon as you debunk one (much like conspiracy theories).

Hence I have tried to give you the basic information to be able to figure out why the idea of 2012 somehow coinciding with an event that will cause a magnetic pole shift has no basis in reality. If you come across (or have) a claim that I haven’t addressed within this topic, please leave a comment!


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