Earth Magnetic Field Reversals

[Bluespace]

i wish to start a discusion related with it, i have searched so many pages, but there is no up to-date news,

what makes it so?
are we now at the reversal period?, witnessing tusnami's, hurricanes???
what will be the consequences??

also i have started a thread for this in my discussion forum http://www.bluespace4u.com/blue/viewtopic.php?t=10, due to no member activity, i'am now trying to find answers for that HERE,

[Don. Edwards]

Earth's polar reversals happen at a fairly regular rate. But it seems we are somewhat overdue. There are signs that it is an impendings event though. Earth's Magnetic field is at an all time low. I don't believe it will impact weather as much as it will the upper stmosphere and it effects on humans.. PBS had a very good special on NOVA last year that dealt with it. You might want to check with your local library to see if it is posible to check it out if they video lending. The other option would be to go to http://www.shoppbs.org/product/index.jsp?productId=1763672&cp=1412584&page=2&doVSearch=no&clickid=lftnav_sbs_txt&pageBucket=0&parentPage=family

and purchase it. It was a very well made program and they only $19.95 for the DVD. Worth checking into.

Don.

[WildMoon]

I also watched it on PBS. Of course, when the polarity reverses, we're gonna have to change alotta things. I also happen to like being in the northern hemisphere and I don't wanna end up being said to be in the southern hemisphere for some reason . Hmmm...with the polarity switch would they swap the names of North America and South America?

[ajtribick]

Hmmm...with the polarity switch would they swap the names of North America and South America?

Probably not, because it would confuse everybody, and also because you can avoid the whole issue by defining north and south by the Earth's rotation.

Earth's polar reversals happen at a fairly regular rate.

There are however fairly major exceptions, e.g. the Cretaceous superchron, between 120 and 80 million years ago, when the magnetic field didn't flip at all.

[Tanketai]

...when the polarity reverses, we're gonna have to change alotta things.

Change things? Like what? Just names and stuff? (pfff...)

But, I mean, is there any danger to electronic devices or electronic data storage? Could it harm us? (OMG, it's the Y2K all over again!!!)

[Malenfant]

...when the polarity reverses, we're gonna have to change alotta things.

Change things? Like what? Just names and stuff? (pfff...)

But, I mean, is there any danger to electronic devices or electronic data storage? Could it harm us? (OMG, it's the Y2K all over again!!!)

Well, there's the small matter of the magnetic field going crazy so parts of the surface would be unshielded from solar radiation that the mag field would otherwise deflect.

Plus halfway through the reversal there'll be magnetic "pockets" that have their own N-S directions, so Delhi in India might be the North pole for Perth in Australia, but Syndey, Aus might be the north pole for New Zealand. In other words, there'd be lots of north poles at the same time... it'd make navigation a lot more difficult.

[Bluespace]

wherver i searchs about it, the only thing i will found is" Only birds migration will be affected"

but like Malefant said

Well, there's the small matter of the magnetic field going crazy so parts of the surface would be unshielded from solar radiation that the magnetic field would otherwise deflect.

so when this happens , actually atmosphere collapses? will be there so much drastic climatic changes? i have heard that it's the magnetic feild that protects earth from those huge solar flares which emits so much radiation, and if the magentic field in the reversal time become weaker, it can prove harmful, right?, but still there is not much scentific notes on that, i live in india, where most peoples can only rely on internet for infos like these, and about buying that dvd for 19 dollars is out of my subject, here 19 dollars means, about 2000 rs

[eburacum45]

There is not likely to be any noticeable effect on the atmosphere or biosphere during a pole reversal - they have happened many times before and there is no sign of any effects on the biosphere in the fossil record.

There might be some effects on electronic equipment and power supplies, espevially if a CME coincides with a period of low magnetic protection; but a little preparation should avoid the worst problems.

[Jorge]

Actually, as far as human life is concerned (and all other life, really), it may have a real impact. Not enough to endanger the survival of the species or their ability to reproduce, but enough to somewhat increase the rate of mutation and the amount of cancer deseases due to higher radiation environments.

The details would strongly depend on the amount of time the reversal takes to happen and on the kind of solar activity that will happen during that time. Large solar storms would definitely be dangerous.

This is actually one good reason to go back to the Moon. During an inversion, the radiation environment on Earth would be close to what a colony on the Moon would experiment regularly. If we can set up a permanent scientific base there, capable of studying how living things cope with those levels of radiation, we'd be more prepared for an inversion on Earth when it happens.

The Earth is more protected, though, even without a magnetic field. We have a nice little gaseous shield over our heads.

(Lunar radiation, BTW, is not quite the same as orbital radiation due to the existence on planetary surfaces of a kind of secondary radiation that spreads from the surface and IIRC tends to be heavier - therefore more damaging - than cosmic rays and the solar wind.)

[scaddenp]

Given that polarity reversals happen many times in the past, and there is an utter lack of correlation with anything going on in the fossil record, you would have to conclude that the effects on biosphere are pretty minimal. You also have little question as to how long does the process take? "Very quickly" is
what geologists can tell you but given the resolution of dating that could be 1000 years. As far as I know, models suggest weakening field strength, then a reversal but supporting data is flimsy from last paper I read on the subject.

[Jorge]

You won't see the effects of reversals in the fossil records. They are not chatastrophic events and do not cause extintions (although they could accelerate the disappearance of populations and species that are already fragilized before the reversal). An increased rate of radiation-related deseases in living creatures is enough to reduce the average lifespan of those organisms but it's not enough to change significantly the amount of offspring they are able to produce overall. Furthermore, in naturally short-living organisms it is hardly noticeable because there's not enough time in their lives for mutations to accumulate and create real problems. Mutation rates also tend to increase, but since there's usually a significant time lag between the appearence of mutations and their phenotypical expression as new characteristics (although in small populations this time lag is significantly shortened), and since the environment would remain basically the same before and after the reversion, the eventual adaptative advantages of some of those mutations would be rather few. Some new species may arise, some other may become extinct, but these will hardly change the natural rate of speciation and extinction.

A different thing, however, are our lives. We want to live as long as possible, and a high-radiation environment will endanger that. We'll likely live less, unless medicine can be used to counter the effects of radiation.

Left on its own, without enhanced medical technology, the species will survive with ease, although individuals will tend to live shorter lives. The same can be said about the biosphere as a whole.

(as a side note, for reasons still poorly known - but which seems to be connected with their ability to repair damaged DNA - species differ quite a bit in their susceptability to radiation. Roaches will probably live through reversals without feeling the slightest of effects. Most aquatic life also, although here the reasons are known: water shields them)

[Michael Kilderry]

Will the occurence of aurorae be affected by the change in the magnetic field? For example, could the reversal cause them to appear near the equator?

[Dollan]

Taken from the British Geological Survey:

Is there any danger to life?
Almost certainly not. The Earth's magnetic field is contained within a region of space, known as the magnetosphere, by the action of the solar wind. The magnetosphere deflects many, but not all, of the high-energy particles that flow from the Sun in the solar wind and from other sources in the galaxy. Sometimes the Sun is particularly active, for example when there are many sunspots, and it may send clouds of high-energy particles in the direction of the Earth. During such solar 'flares' and 'coronal mass ejections', astronauts in Earth orbit may need extra shelter to avoid higher doses of radiation. Therefore we know that the Earth's magnetic field offers only some, rather than complete, resistance to particle radiation from space. Indeed high-energy particles can actually be accelerated within the magnetosphere.
At the Earth's surface, the atmosphere acts as an extra blanket to stop all but the most energetic of the solar and galactic radiation. In the absence of a magnetic field, the atmosphere would still stop most of the radiation. Indeed the atmosphere shields us from high-energy radiation as effectively as a concrete layer some 13 feet thick.

Human beings have been on the Earth for a number of million years, during which there have been many reversals, and there is no obvious correlation between human development and reversals. Similarly, reversal patterns do not match patterns in species extinction during geological history.

Some animals, such as pigeons and whales, may use the Earth's magnetic field for direction finding. Assuming that a reversal takes a number of thousand years, that is, over many generations of each species, each animal may well adapt to the changing magnetic environment, or develop different methods of navigation.

...John...

[Jorge]

Human beings have been on the Earth for a number of million years, during which there have been many reversals, and there is no obvious correlation between human development and reversals.

Note that this "human development" they refer to is the development of the species, not individual development. We just don't know what happened at individual level in previous reversals - the fossil record is way too scarce for that.

In any case, dismissive reports (there are several of them around) usually fail to take into consideration one factor: human life is today twice as long, in average, than it was during previous reversions. The cause of mortality changed dramatically during this period, with a huge increase in degenerative deseases related with old age and with an environment that is, in general, more radiative than before. So even if it was possible to have a clear picture of the kind of life our ancestors had during previous reversals, simple extrapolation of data from them doesn't seem to me valid. They should at least be weighted against medical reports showing what may happen with higher levels of ambient radiation.

Anyway, what's true is that we don't really know what may happen. Even if the situation in itself is far from new, we made it new by changing dramatically our lives and environment since last time. And I'm not entirely sure that the possibility of a magnetic reversal is being faced with enough seriousness from the point of vue of pubnlic health. It seems to me that the general attitude is "we've got time to study it later". We do, of course, but a little more insight wouldn't hurt, methinks.

[Dollan]

**shrugs** I'm not debating you on this, mind you. I just thought it was an interesting opposing point of view. Frankly, I've never studied these reversals in enough detail to offer my own informed opinion.

...John...

[Jorge]

**shrugs** I'm not debating you on this, mind you.

I know. I just wanted to throw a bit of context in.

In fact, that article agrees with most of what I wrote above, namely:

- Things aren't serious when we look at the big picture
- No mass extinctions are going to happen
- The atmosphere shields us pretty efficiently

Where I disagree with the people who dismiss the issue alltogether is in believing that the thing may be somewhat dangerous to suceptible individuals and therefore lower our average life expectancy if new medical techniques won't prevent that. I'm not entirely satisfied with the way my text came through (I haven't been sleeping enough these days), though, I forgot to mention a number of things and this could have transmitted the wrong idea.

For instance, although I didn't write this before, I also think that these new medical procedures and techniques will be a fact: everything that contributes to the treatement of cancer is useful, and that's a very intense field of medical research these days. So I don't think that the impact on human life is really going to happen. I also believe that some species may be harmed by increased levels of radiation. I'm thinking, for instance, of cheetahs, a species that is already pretty frail, definitely endangered, and which doesn't seem to be very sound, genetically. This species and a few others in the same general situation may suffer and even disappear, but it's not clear if the same wouldn't happen even without the reversion and the vast majority of the species will not be harmed in any way.

Something else I forgot to mention is that another source of danger is the combination of a disappearing magnetic field with a depleted ozone layer, but in any case the layer's depletion by itself is already harmful, as those folks in southern Argentina and Chile already know better than they'd like. The reversion may simply potentiate some problems that already exist.

But basically I also tend to have a dismissive attitude even if a bit more cautious than other people's. I think that the issue should be better studied, that's about all. But I'm not worried.

[Hunter Parasite]

**shrugs** I'm not debating you on this, mind you.

I know. I just wanted to throw a bit of context in.

In fact, that article agrees with most of what I wrote above, namely:

- Things aren't serious when we look at the big picture
- No mass extinctions are going to happen
- The atmosphere shields us pretty efficiently

Where I disagree with the people who dismiss the issue alltogether is in believing that the thing may be somewhat dangerous to suceptible individuals and therefore lower our average life expectancy if new medical techniques won't prevent that. I'm not entirely satisfied with the way my text came through (I haven't been sleeping enough these days), though, I forgot to mention a number of things and this could have transmitted the wrong idea.

For instance, although I didn't write this before, I also think that these new medical procedures and techniques will be a fact: everything that contributes to the treatement of cancer is useful, and that's a very intense field of medical research these days. So I don't think that the impact on human life is really going to happen. I also believe that some species may be harmed by increased levels of radiation. I'm thinking, for instance, of cheetahs, a species that is already pretty frail, definitely endangered, and which doesn't seem to be very sound, genetically. This species and a few others in the same general situation may suffer and even disappear, but it's not clear if the same wouldn't happen even without the reversion and the vast majority of the species will not be harmed in any way.

Something else I forgot to mention is that another source of danger is the combination of a disappearing magnetic field with a depleted ozone layer, but in any case the layer's depletion by itself is already harmful, as those folks in southern Argentina and Chile already know better than they'd like. The reversion may simply potentiate some problems that already exist.

But basically I also tend to have a dismissive attitude even if a bit more cautious than other people's. I think that the issue should be better studied, that's about all. But I'm not worried.

Not trying to worry you, but I think Mass extinction is infact, an iminent threat. Because ive made a little correalation between Some major asteroids hitting the earth. My little comparisons were made out of boredom over the summer and are stuck somewhere under my bed and i can't remember them. ok, point is the Asteroids hitting earth go on a schedule of a few million years. The next one is overdue by a good 2 million years or so. We can have a meteor strike that can wipe us out at anytime. For all we know, there could be one coming right now. Also, another thing i wrote in my book of junk, we could lose our atmoshpere in a few millions years because of breakage of the O-zone layer, Decaying of our core, etc.

Feel free to make any corrections. and im trying to sound indefinent because my theories arent proven, so they could be wrong.

[Michael Kilderry]

Not trying to worry you, but I think Mass extinction is infact, an iminent threat. Because ive made a little correalation between Some major asteroids hitting the earth. My little comparisons were made out of boredom over the summer and are stuck somewhere under my bed and i can't remember them. ok, point is the Asteroids hitting earth go on a schedule of a few million years. The next one is overdue by a good 2 million years or so.

Just because we've been lucky for quite sometime doesn't mean we are going to be hit by an asteroid any minute now, minor bodies having collisions with the Earth is more of a random thing, not a thing that has a rhythm or a pattern of occurence.

We can have a meteor strike that can wipe us out at anytime. For all we know, there could be one coming right now.

I think that most asteroids that are large enough to cause serious damage to the Earth would be discovered before they impact. If there was a meteor heading our way for a collision course in the near future, someone would know about it.

Also, another thing i wrote in my book of junk, we could lose our atmoshpere in a few millions years because of breakage of the O-zone layer,

We aren't going to lose all of it in a few million years though.

Decaying of our core, etc.

I don't think that will happen for a long time.

Feel free to make any corrections. and im trying to sound indefinent because my theories arent proven, so they could be wrong.

And there you are.

[Malenfant]

Not trying to worry you, but I think Mass extinction is infact, an iminent threat. Because ive made a little correalation between Some major asteroids hitting the earth. My little comparisons were made out of boredom over the summer and are stuck somewhere under my bed and i can't remember them. ok, point is the Asteroids hitting earth go on a schedule of a few million years. The next one is overdue by a good 2 million years or so. We can have a meteor strike that can wipe us out at anytime. For all we know, there could be one coming right now. Also, another thing i wrote in my book of junk, we could lose our atmoshpere in a few millions years because of breakage of the O-zone layer, Decaying of our core, etc.

Feel free to make any corrections. and im trying to sound indefinent because my theories arent proven, so they could be wrong.[/color]

This is nothing new, and nothing predictive either.

[Jorge]

Well, the others already replied what I would reply on the asteroid thing (and good that they did too, because I don't read green text), but I must add a little something:

Mass extintion is not imminent: mass extinion is a fact, caused by human activity. We're losing tens of species every year especially due to habitat destruction, particularly in the rainforests of the world (because they are the most species-rich ecosystems we have or, in jargon, the most biodiverse).

What I wrote before was that a magnetic inversion in itself would not cause a mass extintion, and we know that because no other inversion did. But an inversion now would put an extra factor of environmental stress to a seres of ecosystems that are already extremely stressed. And that is definitely bad news.