"Over the last 200 years, the magnetic field has lost around 9% of its strength on a global average. A large region of reduced magnetic intensity has developed between Africa and South America and is known as the South Atlantic Anomaly."
The South Atlantic Anomaly is interesting. In past years satellites are being made to shutdown while passing the regions to avoid damage from the lack of protection from harmful particles.
Not the original commenter but I am in the industry, and its true, many satellites shut down during this region over the South Atlantic.
For that reason, it is not a popular orbit unless there is a larger driver behind the selection. For example the ISS goes right through it in order to be above Russia for a reasonable portion of its orbit. I believe Astronauts have reported increases in optical flashes during this part of the orbit as more energetic particles pass through their eyes.
we can't coordinate basic health care communication on an emergency. Let's hope someone finds a way to place Advertising on those big magnets in case we came to need them.
If the magnetic field completely disappeared tomorrow the top layers of the atmosphere would start to be ionized and stripped away. There'd also be a slow change in the composition of the atmosphere due to neutron bombardment.
The process would only take a mere million years or so!
In the meantime the Earths atmosphere alone also blocks cosmic radiation to the extent that there's no immediate harm to life.
Geologist here: no. Geomagnetic field reversed thousands of times in the Phanerozoic (last 650 My) without any relation with mass extinction events. Organisms can deal with this kind of events.
More info? According to Wikipedia, the Phanerozoic Eon has been lasting for 541 million years (I rechecked because wasn't sure what My meant at first). How would we even detect extinction events from a few million years back? Also, hundreds of millions years divided by thousands of geomagnetic field reversals sounds like very rare (considering the briefness of human existance). Also, ecosystem collapses are probably not all the same: there's gigantic explosions (a la dinosaur killer), there could be ocean acidifaction, etc.
There are a lot of good pop science books to read about the history of life on earth.
"The Ends of the World" is probably the best one. "The Rise and Fall of the Dinosaurs" is also a good one, and it doesn't focus purely on the dinosaurs as the title suggests, but about how we know how they evolved and existed.
Yes. Some technology and techniques will trickle down from defense and aerospace like it usually does. Manufacturing will be scaled up and infrastructure retrofitted. Events much more traumatic like an atmospheric EMP have been a design concern since shortly after we developed nuclear weapons. We've got well understood technology to solve any issues that come up.
Alanna Mitchell's "The Spinning Magnet" is a good popular-level book on the Earth's magnetic field, how it was discovered and investigated, and what's currently known about it: https://www.indiebound.org/book/9781101985168
Space-based X-ray telescopes also need to take the South Atlantic Anomaly into account; data taken while the instrument is in the SAA is disregarded.
Yes, but it's very localized. The magnetic field of earth is typically modeled as a dipole where the magnetic field strength is the same as you go around the equator at the same altitude.
Maybe with northern lights over equator, I'd have to think about it more, but it's odd to think of an aurora where the magnetic field lines are parallel with the ground rather than normal to the ground (particles are much more mobile along field lines rather than across field lines in plasmas).
When space weather activity increases and more frequent and larger storms and substorms occur, the aurora extends equatorward. During large events, the aurora can be observed as far south as the US, Europe, and Asia. During very large events, the aurora can be observed even farther from the poles.
That's a very weird and not very precise way to word this. Of course I would expect auroras to be regularly visible in the far northern parts of the USA and Europe:
Should be possible to estimate how long it would take to hypothetically spread over the whole globe (this probably won't happen). Any idea what time scales we are talking about here? My best guess based on the animation would be ~50 years rather than hundreds of years, but would be nice to have a solid estimate rather than guessing.
Could this time of field weakening and events such as cambrian explosion[0] be related?
Does any human activity impact Earth's magnetic field directly or is it irrelevant at this scale? Activity like mining metals out of the planet, large amounts of construction. Movement of metal in ways of air planes and vehicles.
If molten magma is the source of our magnetic field and the earth slowly spews out lava over time, is it causing out magnetic field to weaken over time?
This might be slightly offtopic but what do you make of the concept that magnetic fields and global warming might be associated? [1]
> Activity like mining metals out of the planet, large amounts of construction. Movement of metal in ways of air planes and vehicles.
That is ENTIRELY insignificant, and not even worth mentioning. The deepest hole humans have ever been able to create was about 12km deep. That is less than 0.18% of the earth‘s radius.
Human activity is limited to the upper parts of earth‘s crust, which is itself only a fraction of earth. Magnetism happens WAAAAAY deeper.
"The deepest hole humans have ever been able to create was about 12km deep."
This interesting: We've sent humans 384400 km away from our planet, we've sent an object more than 22E9 km away [1], yet we cannot drill a hole deeper than 12 km into our own planet.
You hit a temperature/pressure threshold pretty quickly once you start going down.
It's hard to engineer materials or machinery that can cope with the kind of pressures and temperatures created when drilling deeper than a few kilometres.
Also pouring government funds into something like this is not as glamourous as manned space flight missions. A good example is that we know more about the surface of the Moon than we know about the ecosystems in the Mariana trench.
> Human activity is limited to the upper parts of earth‘s crust, which is itself only a fraction of earth. Magnetism happens WAAAAAY deeper.
But doesn't that assume that metal/mineral deposits closer to the surface, or at the surface, those that humanity has mostly exploited, do have no effect at all?
What if surface deposits and those closer to it act as some kind of "coating" leading to slight changes in dynamics we still don't understand or might not even realize yet actually exist? When we are very much like ants: In the singular seemingly insignificant, a single ant would never be seen as capable as "harvesting" any bigger animal carcass. Yet the scale and endurance of these ants make it possible for them to slowly pick apart something that would normally consider them quite insignificant in their actions, very much like we've been doing for a very long time.
In that context, I'm kinda skeptical about how often the impact of human activity is belittled as supposedly having an "insignificant" contribution to global-scale environmental changes. Reminds me way too much about how climate change is to this day still argued as something "natural", and many past human activities that were declared "safe and inconsequential" at the time, ended up still having very real lasting and global effects, like atmospheric nuclear weapon tests.
It makes me wonder how much of that argument is connected to religious beliefs along the lines of "Humans could never seriously threaten or impact God's creation, and if we do, then God intended for it to do so", which sometimes manifests in weird ways like considering environmentalism as a form of "native evil" [0]
We also diluted their concentrations and refined them, so it's not only "just moving them a few km up", we spread it way out in way smaller concentrations than natural deposits tend to be, which prior existed in very different structures due to the way they get formed.
And to note: I'm not saying that's actually a thing, what I'm taking issue with is these reflexive declarations of human activity supposedly being "too insignificant" as regularly being the go-to answer to many environmental changes and issues to categorically deny human activity as having any and all influence on them.
Imho that's just short-sighted and belittles how often we have been absolutely wrong with that kind of approach, only to then later having to admit "We fucked up and now there's not really a way to fix it, our bad".
Because contrary to popular belief, not even 21st-century humanity is without flaws, we are not omniscient, even when quite often pretend to be to justify that kind of false hubris of "insignificant human activity".
The difference to climate change is that the earth never experienced such a rapid change in climate short of cataclysmic events in the time periods we can indirectly observe, whereas the earth's magnetic field changing happened quite often and quite suddenly even before humans came around.
And the similarity is how for literally decades that possibility was either belittled or quite bluntly suppressed when the changes couldn't be as directly observed and didn't as directly impact us, as they are doing by now.
That's what I take issue with, I'm not arguing that changes to the magnetic field are without a doubt the result of human activity, I'm merely taking issue with how quickly and nonchalantly such possibilities are hand-waved away with "human activity is just too insignificant".
When by now it turns out human activity has been significant enough to kick-off a process that can be very much described as "terraforming", or rather "venusforming" terra.
The disparity in the magnitudes of energy involved should mean human activity has a negligible effect. When you consider how massive earth is, how massive the core is, and how much energy it takes for the core to have the angular momentum it currently does, what few things we are doing to the crust aren't relevant except in very localized areas that do not extend to the height of these satellites.
I thought the Cambrian explosion was more closely related to the oxidization of the atmosphere by pond scum. Free oxygen becoming available in the atmosphere for organisms to use allowed the formation of collagen and chitin, both of which are necessary to form the large structures complex life needs, and also allowed for more efficient breathing, which allowed for larger and more complex life.
That word oxidization or oxidation is really misleading! It's not that the atmosphere was oxidized but the opposite - CO2 was reduced to produce free oxygen molecules. I think it should be called "oxygenation" instead.
Interestingly the first person to talk about pole reversals was the American holistic healer Edgar Cayce. On the 11th day of August, 1936: Q What great change or the beginning of what change, if any, is to take place in the earth in the year 2,000 to 2,001 A.D.?
(A) When there is a shifting of the poles. Or a new cycle begins. Ref [826-8]
Geologist of the time did not believe a word of it. However, during WW2 the detecting instrumentation for submarine warfare detected on the sea floor alternating bands of magnetic polarization, which is now evidence for the reversal of the magnetic poles. Humans do have non-physical experiences, e.g. dreams, etc. but now most non-physical experience is discounted, ignored, except for thinking.
> When there is a shifting of the poles. Or a new cycle begins.
He actually is not talking about magnetic poles. He clarifies further:
"There will be shifting then of the poles – so that where there has been those of a frigid or the semi-tropical will become the more tropical, and moss and fern will grow. And these will begin in those periods in ‘58 to ‘98, when these will be proclaimed as the periods when His light will be seen again in the clouds. As to times, as to seasons, as to places, alone is it given to those who have named the name – and who bear the mark of those of His calling and His election in their bodies. To them it shall be given." - https://www.edgarcayce.org/about-us/blog/blog-posts/cayces-p...
> Geologist of the time did not believe a word of it.
I mean, did anybody ask them? Perhaps they would have been familiar with Professor Matuyama's work.
Finally, how many other predictions did he make? Any chance people have cherry-picked a couple of his ideas that seem kind of close to right?
This is why claims without evidence are effectively meaningless.
It's not enough to have a belief. At the very least, you need a logical derivation of your theory.
If I threw out a prediction in this comment that just happened to become true in 100 years, should I get any credit for it? Should people think that I somehow had some special insight? No.
Logic & evidence. Those are the only things of value when make claims or predictions.
I'd recommmend Sunfall by British physicist Jim Al-Khalili as an entertaining fictional account of the catastrophic effects of an weakening in the Earth's magnetic field, followed by attempts to remotely restart flow activity in the core.
Since Earth’s magnetic field derives from the convection currents of magma in the outer core, and since moving magma also drives tectonic activity... is there any potential relationship between this anomaly and earthquakes/volcanos?
The magnetic field is generated in the outer core, while surface vulcanism and earthquakes are driven by the upper mantle. These areas are about 2,000 miles different in depth. There's obviously some kind of relationship because it's all one planet, but nothing direct enough to care about in this situation.
"Sorry to disappoint the "we're all going to die" crowd, but the South Atlantic Anomaly has been developing at least since 1840, and appears to be an effect of long-term, mysterious flows in Earth's outer core."
According to Wikipedia [0], there have been 183 magnetic reversals the past 83 million years (and many more throughout the history of the Earth, including the reign of the dinosaurs). The weakening of the Earth's magnetic shielding is no laughing matter, but the impact of the Chicxulub asteroid was certainly far greater.
I know almost nothing about this but I'd say this is unlikely. The dinosaur era spanned millions of years and the poles flip several times per million years. So they survived through dozens of flips.
There was a 2013 paper titled "Mass Extinction and the Structure of the Milky Way" that you might find interesting: https://arxiv.org/abs/1309.4838 - I don't know if there have been any significant follow ups since it published.
Basically our galaxy is a spiral galaxy with four arms, and it's rotating. The center moves slower than the outside, and our sun's orbit is near the inner rim of the Orion arm. We orbit the galaxy roughly every 240 million years and in that time we cross the dense galactic arms every so often (arms aren't symmetrical).
The paper: "A correlation was found between the times at which the Sun crosses the spiral arms and six known mass extinction events."
I'm not sure what you responded to since it was removed, but I assume it was something to do with the subject of the article...
Why would all magnets cease to work if the Earth's magnetic field went funky? Surely neither the magnets on my fridge nor the magnets in a train's electric traction motors do not depend on the earth's magnetic field being oriented any particular direction. I'm not sure, but I think AC train traction motors don't even have permanent magnets in them. Compasses would get messed up though.
I. I just honestly don't understand what you're saying. Or where you would've come up with that. Or what the purpose would be. Or why you even think this exists.
Coal, oil, gas fossil fuels are all contained in the earth's crust and make up an extremely small fraction of it. The crust is just 1% of the volume of the planet and the mantle that the rigid plates float on is 84% of the volume.
I'd wager that all the crude fossil fuels in the world might be able to have a minor impact on a single decently sized volcano if it were all in one spot beneath it, but it's not.
The views above are primarily opinion formed off the cuff combined with a few minutes of research. I'm open to being shown that I am incorrect.
While life developed pretty much right away, multicellular life has existed for less than 15% of earth's existence. All of earth's coal is from an even more recent period when plants had newly developed wood and nothing could decompose it yet.
Earth seems to have been just fine without hydrocarbons for most of its existence.
That still gives us a 100 million years or so. Even our best drilling/mining tech is quite inefficient thankfully. The result of burning that energy on the surface will hit us way sooner.
By looking at the video it looks like an anomaly in the Amazonas. What is causing this? Deforestation?
If so we need to change economic system to one based on nature. So that eco systems have an economic value. Ie a tree in Amazonas has a value to earth and its inhabitants since it provides oxygen. In current market economic system common resources are not priced fully. It may be profitable to chop down tree and sell the wood. Use previous Amazonas land for example to create more farmland to breed cows.
The South Atlantic Anomaly is interesting. In past years satellites are being made to shutdown while passing the regions to avoid damage from the lack of protection from harmful particles.