Weakening of Earths magnetic field due to geomagnetic excursion

[Christopher Shriver]

7 hours ago, N8daGr8 said:

I am fairly new to this subject. Here are my 2 cents. Christopher said this above. 

On 5/6/2024 at 11:04 AM, Christopher Shriver said:

We must remember that astrophysical stuff occurs on a scale of time that is very much larger than any individual's lifespan, let alone a species.

Our modern technology has never seen a geomagnetic excursion and the only evidence that we can find that it has happened is in the environment around us. Scientists, or even pseudo-scientists create theories and try to find evidence to support their theories. Some pull data from extremes and make assumptions in hopes to confirm their theory. We have no idea what a geomagnetic excursion looks like on all of these new fancy diagrams because it has never been recorded.

I'm totally with you so far.

7 hours ago, N8daGr8 said:

I like the youtuber's videos because it encourages me to go out and find more opinions and more data to confirm/deny theories. I also regular these forums because it gives me more perspective. I like reading the articles he presents and seeing how it matches or doesn't with his claims. 

I'm certain there are beneficiaries to that style of content - the issue lies in the format and presentation of information, more often than anything else. Not to mention common pseudo-science as a secondary mark against them. There are vulnerable folks who do not take this time to research, and will accept the narrative presented as truth, without personally validating this worldview-impacting information. Your curiosity is precious, and growing more rare these days among others. Without it, you too would remark on being misled to fear certain aspects of science, as others have remarked on this website over the years.

7 hours ago, N8daGr8 said:

Catastrophism is full of theories. Usually extreme theories. Most occurrences fall somewhere in the middle of 2 extremes. Most scientific theories around the earth's magnetic excursion claim that they happen over millennia. And most data confirms this claim. There will always be anomalous occurrences that will point to the extremes. If you form a theory off an anomaly, you could create some fantastical stories and claims. 

Could his claims and theories be true? Sure. But I wouldn't base my lifestyle, preparations, or fears based on any youtuber's or even scientist's theories that I don't know/trust. 

Overall, you gave what I think is the most valuable advise there is to give. Regardless of credentials, all are prone to error and misguidance, not merely through organic faulting but perhaps a quantum "series of determinants." A sentiment against the enterprising of disinformation is the core of our community's opposition to such figures, if I have read the room correctly thus far, although I personally encourage more inventive ideas, which promote chances for questions that have never been asked, before. Discoveries lay on that path. I'd love to help expand the perimeter of our collective ignorance untoward the Universe.

It's hard to fear geomagnetic excursion when other more likely threats to security and wellness are far less hypothetical and far more realized. Aim squarely your passion for learning at these subjects, saving paranoia for realistic, active, and extreme dangers.

[Yav]

Hello all. I've read all of the responses and I have a few more questions to ask. My apologies if the questions I have are answered already, I would appreciate the linked answers or articles.

From my understanding, geomagnetic poles and magnetic poles are two separate entities. What exactly is shifting and what effect does it have on us in the near future?

From the information that I've seen in another thread, the magnetic strength is weakening, but it is shown that it is a regression to the mean which I can wrap my head around.

What exactly does a geomagnetic excursion entail? What is shifting (geomagnetic poles or magnetic poles) and what is the difference?

Is the magnetic strength or geomagnetic strength weakening?

Is there any evidence of what we could expect between the relationship of our sun and the Earth in the coming years?

[Philalethes]

1 hour ago, Yav said:

From my understanding, geomagnetic poles and magnetic poles are two separate entities. What exactly is shifting and what effect does it have on us in the near future?

Yep, correct. What's rapidly moving is the north magnetic pole, which is essentially the strongest localized part of the field, where the vertical component of the magnetic field goes straight down (hence why the magnetic poles are also called dip poles). This is the direction in which a compass will tend to actually point, although the overall field isn't so straightforward; the angle between true north (i.e. the geographic north pole) and the direction a compass points it's called magnetic declination, and as you can see from a recent map it's not exactly a perfect dipole:

In this video you can see the magnetic north pole (small green dot) as modeled over the past ~400 years, and the fairly rapid movement we've seen lately.

More interesting is perhaps why it has moved so rapidly lately. In Recent north magnetic pole acceleration towards Siberia caused by flux lobe elongation there''s a very good explanation of what's going on. Essentially there is magnetic flux emerging from two relatively large "lobes" in the Northern Hemisphere, the Canadian lobe and the Siberian lobe. On their own each of these could be considered their own magnetic pole, bue the combination of the two causes the actual magnetic pole to lie somewhere along a line between them where the field is nearly vertical; as they write:

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Considered in isolation from the remainder of the global field, each Earth-surface patch of strong radial field would define a magnetic dip pole close to its centre point. The present two-patch structure of the high latitude geomagnetic field then defines two ends of a linear conduit of near vertical field along which the north magnetic pole can readily travel.

Probing a bit further into why there exists fluctuations, it's pointed out that the field we measure on the surface goes through a complex mapping from the so-called core-mantle boundary (CMB), and that changes to this mapping will lead to different structures of the surface field; as they summarize:

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We find that the time-dependent position of the pole along the conduit is largely governed by a balance or tug-of-war between the competing influences of the Canadian and Siberian lobes on the CMB.

In terms of those lobes they go on to explain that what's happened is that the Canadian lobe has become elongated and nearly split into two separate lobes, with one of them being closer to the Siberian lobe, both of which contributing to the magnetic pole moving towards the Siberian lobe. Before concluding they also touch upon the physical mechanism deemed most likely to be behind these changes, which is variations in the flow of Earth's liquid outer core, which is what's generally assumed to generate the geomagnetic field.

The final section where they touch upon the history and potential future of these changes is the most interesting if you ask me. There they among other things point out that according to the models they've used, which match the observations quite well, it wouldn't take much for the movement we're seeing to reverse:

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Will the north magnetic pole ever return to Canada? Given the delicate balance between the Canadian and Siberian flux lobes controlling the position of the pole along the trough of weak horizontal field, it would take only a minor readjustment of the present configuration to reverse the current trend.

Further they point out that according to those models you typically see two, sometimes three, such relatively distinct surface patches of field that combine to place the magnetic pole; over the past few centuries it's apparently been stable around Canada (as seen in the video linked to above), but going further back it seems to fluctuate chaotically around the geographic pole; they write:

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Over the last 400 years, the pole has meandered quasi-stably around northern Canada, but over the last 7000 years it seems to have chaotically moved around the geographic pole, showing no preferred location. Analogues of the recent acceleration may have occurred at 4500 BC and 1300 BC when the speed reached about 3-4 times the average seen in these reconstructions. The most recent of these events coincided with the pole moving towards Siberia (from a region close to Svalbard) where it remained stable for several hundred years

This to me seems to indicate that while we haven't seen the magnetic pole move this rapidly for a few centuries, in the long run this isn't really anything that special, and certainly nothing that would indicate some major change like a geomagnetic reversal, especially considering those last two sentences where it's pointed out that the movement was even more rapid and the pole ended up fairly stable for centuries like it's been for the past few centuries before the recent movement.

So ultimately I think the only effects it will have in the near future is some continued changes in magnetic declination; make sure to keep a recent such map on hand if you live in an affected area and plan on navigating by compass!

I'll also address your other questions, albeit a bit more briefly, as the above should at least give some idea about what's going on.

4 hours ago, Yav said:

What exactly does a geomagnetic excursion entail? What is shifting (geomagnetic poles or magnetic poles) and what is the difference?

To explain what a geomagnetic excursion is, it first bears explaining what a geomagnetic reversal is. A geomagnetic reversal is an event that happens every 500 kyr (kiloyear, thousand years) on average based on our records, where the entirety of the geomagnetic field itself flips, much like we see happen with the heliomagnetic field every ~11 years or so (the Solar cycle); what is now the north geomagnetic pole becomes the south geomagnetic pole, and vice versa (technically the other way around, as the geomagnetic pole in the Northern Hemisphere has southern polarity, strictly speaking, which is why the northern magnetic pole of compass needles point to it). The last time this happened was ~800 kya (kiloyears ago), the so-called Brunhes-Matuyama reversal.

A geomagnetic excursion on the other hand is when the geomagnetic field weakens to the point where it seems like it's undergoing a reversal, where large-scale movement of the dipole field is observed, and with higher-order moments (like the quadrupole moment) becoming more prominent, but without ultimately ending up reversing, and instead returning to its original configuration.

So the difference between this and some smaller-scale movement of the magnetic poles, as explicated above, is quite significant. It entails the field becoming far weaker than we've currently seen, and the aforementioned effects of the geomagnetic field (large-scale movement of the geomagnetic poles and higher-order moments becoming stronger relative to the dipole moment).

4 hours ago, Yav said:

Is the magnetic strength or geomagnetic strength weakening?

When we talk about the strength what we talk about is typically the dipole moment of the overall geomagnetic field. That is what's weakening (as per what I assume you've read in the other threads).

4 hours ago, Yav said:

Is there any evidence of what we could expect between the relationship of our sun and the Earth in the coming years?

Not really in terms of changes to the geomagnetic field, at least none that I'm aware of. The geomagnetic field weakening will in principle cause more particles to penetrate deeper into the atmosphere in various ways, but over the span of time we're talking about the effect is likely going to be small; as shown on the last page the field strength has dropped ~5% over the last 80 years or so, so if that trend continues you might see another 5% drop by the time you're old, and there's certainly no guarantee that the effect on geomagnetic activity is inversely proportional with that drop (i.e. a 5% drop will not necessarily lead to a ~5.3% increase in geomagnetic activity), in fact I strongly doubt that it is.

I also think the weakening will probably slow down eventually too, which we might even observe clearly during our lifetimes if it happens; according to the best model, which is assumed to be very accurate for such a short time ago, around 1700 an equally strengthening trend stopped and reversed to the current weakening we're seeing, which happened over just a couple of decades.