In the interests of actually providing some form of information (rather than merely saying "this is what the Doomsayers say")...
It's moving at the moment, so yes.
Apparently 40+km a year, at the moment. At least that's the case for the spot on the Earth's surface where the North Magnetic Pole 'is' (where the 'south' pole's field lines of the internal magneto-dynamic... thingy... come straight up out of the ground, rather than at an angle, which may or may not relate to where the vertical field lines are at any other depth or altitude...). And it has been moving faster, but then it is a chaotic system, so I wouldn't read anything into that.
The Southern Magnetic Pole (the 'north' pole of the Earth's magnet) is apparently drifting only about 10km, at the moment, depending on where you check. And whereas the Northern entity is 80-odd degrees North, the Southern one is only about 60-odd degrees South (and both significantly around the 'back' of the planet (the IDL-side of the "90-degrees East and West" slice), also.
(Actually, after writing the above, I found that I may have been interchangably using references to the "Magnetic" and "Geomagnetic" poles, the latter being the intersection with the Earth's surface. You'll excuse me if I don't trawl through everything
again to make sure that what I was talking about (the Geomagnetic one) didn't include the odd reference to the other by mistake. Especially given it's a mistake/shortcut a lot of people would make anyway.)
Doesnt' the earth's magnetic field switching take, like a couple hundred thousand years?
Sort of. Sometimes it 'flips' very rapidly by geological standards, which could be anything from nigh instantainious to a century or two.
There are also "excursions" of the magnetic field (temporary collapses, maybe 1/5th the strength), as well, these seem to
last on the order of 10^3 or 10^4 years, but how long they take to actually 'spin down' to start with and resolve themselves at the end is unknown (or even if excursions are actually 'not quite' reversals, or reversals 'flipped back the wrong way' recoveries from an excursion). And at this point I think I should point out that there's never been an Extinction Level Event unambiguously associated with these long-term episodes. You could argue because it's a long enough period for any ELE to 'get lost' in it and blamed upon the usual suspects, but there's valued opinion that the solar wind itself keeps the magnetosphere 'spinning' even when the Earth doesn't support it.
Gods know that there's plenty of other stuff (volcanism, asteroids, life itself causing problems like flooding the planet with that poisonous gas, oxygen) that can claim to cause ELEs. I think the main interest that Man would have in a flip is in how it affects power-distribution technology (which is already threatened by solar events) and 'lodestone'-era navigation.
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Topic: 2012 (Read 9719 times)