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North Pole Heads South
blamanj writes "Things are not looking good for Santa. First, news that it's getting warmer at the North Pole, and now, scientists report that the (magnetic) pole itself is on the move. 'Earth's north magnetic pole is drifting from North America at such a clip that it could end up in Siberia in the next 50 years.'"
Is this a part of the cycle of the reversal of Earth's magnetic field? I always though that this cycle took much much longer ( but 1/3 of the way down in under 50 years?).
When I went to school I was taught that the magnetic poles swap places once every 23,000 years, so I guess the NP (or should it be SP - who knows?) is just getting ready to leave.
The so-called "North Pole" is actually a south magnetic pole. Think about it: the north pole of any bar magnet you use as a compass points "North", but with magnets, opposite poles attract, so the north magnetic pole of a magnet points towards the strongest nearby south magnetic pole, so if it's pointing North, there must be a south magnetic pole up North somewhere! Likewise, the South Pole is a north pole.
qntm.org
There is no timetable on which the poles reverse, and it doesn't happen at regular intervals. Yes, I believe the time since the last reversal is longer than the mean time between pole reversals, but the term 'overdue' does not apply here.
Mathematics is made of 50 percent formulas, 50 percent proofs, and 50 percent imagination.
But this site sure has them and this site has some too.
Read them. They are worth it.
It looks like there are two magnetic norths on the planet. Our current one looks like it is just the additive of the major and minor magnetic fields of the earth with their collective strengths oscillating over time... hence the apparent movement.
Could be interesting times (mental note: buy manual tin opener)
-- Intelligence is soluble in alcohol
The magnetic North Pole has never been a single point.
It has always been a general area, and at any given point of time, the *actual* North Pole would be somewhere in that area.
So, given that, this is not really surprising.
-- Intelligence is soluble in alcohol
There's a long period around the reversal when the earth's magnetic field is dowm. No protection from cosmic rays & other miscellaneous high energy particals. Hundreds of years. One resource on the Brunhes-Matuyama reversal about 780K years ago is: here. Here's another more general one on reversals from NASA.
If you want your life to be different, live it differently.
No... flush rotation has nothing to do with the magnetic field. It is related to the coriolis effect (http://en.wikipedia.org/wiki/Coriolis_force) though it seems that the field of physics now implies that the coriolis force is too weak to manifestly impact fast moving water going down the tube. The velocity is a result of conservation of angular momentum. Flow direction (influenced by coriolis) is more impacted by the shape of the container.
The geographic north pole is north by definition, the magnetic north pole is not - so it can head south.
James P. Barrett
that would be a very bad thing. The magnetosphere currently protects our planet from the solar wind. A significantly weakened magnetic field would allow the solar wind to ionize Earth's atmosphere and carry it off into space (read this NASA webpage for more info). Needless to say, that would be very bad. Polarity reversals have occurred frequently in Earth's history, and some argue that they coincide with mass extinction events.
Bzzt.
i gation+by+animals
http://www.google.com/search?hl=en&q=magnetic+nav
um, no, it's not that bad, you seen too much movies!v iew.html
http://www.badastronomy.com/bad/movies/thecore_re
having said that, question is what would happen to birds and other animals that navigate by the magnetic field. anyone know?
if (!signature) { throw std::runtime_error("No sig!"); }
The North pole is NOT defined by magnatic north, but by the axis of rotation of the earth. The magnatic north and the true north pole do not lie on the same place. That's no news.
Well hmm according to http://image.gsfc.nasa.gov/poetry/venus/RevScience .html the earth's magnetic field does not cause mass surface life extinctions. If you would like to make an assertion like that, you really do have to back it up with something. In fact it will cause little change in the way things function, maybe a few thousand extra cases of cancer each year. Now if the field never came back and our atomosphere ionized, then we would be screwed.
Supercomputer simulations do not show that. According to the site: "Reversals take a few thousand years to complete, and during that time--contrary to popular belief--the magnetic field does not vanish. 'It just gets more complicated,' says Glatzmaier. Magnetic lines of force near Earth's surface become twisted and tangled, and magnetic poles pop up in unaccustomed places. A south magnetic pole might emerge over Africa, for instance, or a north pole over Tahiti. Weird. But it's still a planetary magnetic field, and it still protects us from space radiation and solar storms."
False. Cosmic rays *are* deflected by magnetic fields - they are charged particles. (Well, most of 'em - cosmic ray is a tad vague - let's say the ones that are really bad for us.)
Magnetic fields and water/ice are two methods proposed for protection during space missions.
Luckily the earth has plenty of atmosphere to protect as well.
A quick google shows that this incorrect. The atmosphere continues to block most incoming radiation even during those times when the magnetic field has completely collapsed. 'Cosmic ray' is not the right choice of wording here, either-- very little of the incoming radiation meets the definition of cosmic ray, which is good because neither the magnetosphere nor the atmosphere provides much protection against true cosmic rays.
Magnetic field reversals coincide with mass surface life extinctions
This is completely incorrect. There have been numerous studies to look for correlations between pole reversals and extinction rates; no significant correlations have been found by any of the serious researchers (though it is currently fashionable among the half-baked set to claim otherwise--- the fun of Chicken Little Syndrome).
Here's one reputable source: the British Geological Survey. Google will reveal thousands more, but you'll need to sort out which ones are authoritative and which suffer from CLS.
GPS Satellite are NOT in LEO. The GPS constellation orbits at 20,200 km. This is between the LEO sats: Iridiums (780km), the Hubble (569 km), the Space Station (351 km); but much lower than geosynchronous communications or weather satellites (35,786 km). They orbit the earth twice/day.
For a really cool visual demonstration, check out J-Track 3D over at the NASA web site. The GPS satellites are just about the only thing you find between the cloud near the earth, and the Clarke Belt.
- AlanH