Earth's magnetic field collapsing!

[Alex]

All the cool kids will die off of skin cancer

Then the chicks will be ours!!!!!!!!

Except that the chicks will also die off of skin cancer. So I think you better start considering homosexualism.

[Kuciwalker]

We can KIDNAP the chicks and make them stay indoors

[Ned]

Originally posted by MrWhereItsAt

Heh. If it was on the Discovery channel then I saw the same programme. But I can claim to have some more knowledge from a few Honours level Physics papers in Geomagnetism.

This change is NEVER instantaneous, unless you count a few hundred - thousand years as immediate. At the current rate we have several tens of thousands of years before there is any real risk of extra cosmic radiation at ground level. And we are 'overdue' by several hundred thousand years (the average time between reversals has been 200,000 years, we have gone 700,000 since the last one) for a reversal in the same way Wellington is 'overdue' for a magnitude 8.0 earthquake.

* MrWhereItsAt wishes he knew what actually gave rise to the 'secular' variations in magnetic fielde strength...

What causes it? Solar Flares?

[The Andy-Man]

maybe this has something to do with the 'rise' in temperatures. ie, another possible explanation for 'global warming'

[Ned]

The Andy Man, I find it more than interesting that the reduction in the magnetic field coincides with end of mini ice age.

During the recent spate of solar flares, news reports showed just how those flares impacted the Earth's magnetic field. The flares would counteract the field, reducing it. This has got to act as a drag on our core's rotation in some fashion.

However, a reduction in the field does not explain why the magnetic field flips. It would be interesting to see what the causation theories are rather than just note that the flips occur. For example, can the effect be reproduced in computer models?

It just seems to me that the cause of the flip must be some force acting on the core external to the earth. It also seems to me that the most likely candidate for the source of the influence is the sun.

[monolith94]

so... when do I get my super-powers?

[General Ludd]

Originally posted by Smiley
So is it this decrease in magfield strength that explains the rise in cancer rates, or is that smog really that bad?

I thought it was all the nuclear testing.

[Frozzy]

What causes it? Solar Flares? [/QUOTE]

What causes what? If you mean the cosmic radiation, then that is from the flares from the sun, yes.

[Ned]

Frozzy, no, what causes he reduction in magnetic field strength?

[Frozzy]

The liquid core changes the direction of the electric current, so instead of going north to south, it goes south to north. This takes a very very long time. It has to weaken the strength of current before it can change the direction.

[Ned]

Frozzy, is this phenomenon entirely self-contained or is it influenced or induced externally to the Earth?

[Ned]

Just as an example of what I mean, the Earth's axis of rotation itself rotates 360 degrees as we traverse around the galaxy. This implies a conservation of momentum on a galatic scale. Could something similar be happening to the Earth's core in response to solar or galatic fields?

[Kuciwalker]

The Andy Man, I find it more than interesting that the reduction in the magnetic field coincides with end of mini ice age.

Didn't someone already point out that this was mere coincidence, as it wasn't until that point that we started measuring the phenomenon in the first place?

[Ned]

Skywalker, oh. We have no magnetic field data prior to 1845?

[Frozzy]

We do, actually.

Take ancient pots or Hawaiian lava for example. When rock cool quickly, they are magnatised according to the status of the magnetic field. Samples of lava in Hawaii from ~ 750,000 years ago have an alignment of anywhere between south, east, north east, north west. Those of ~1,000,000 years ago are south aligned.