Posted on 04/10/2002 2:33:45 PM PDT by aculeus
The Earth's magnetic poles might be starting to flip say researchers who have seen strange anomalies in our planet's magnetic field.
The magnetic field is created by the flow of molten iron inside the Earth's core. These circulation patterns are affected by the planet's rotation, so the field normally aligns with the Earth's axis - forming the north and south poles.
But the way minerals are aligned in ancient rock shows that the planet's magnetic dipole occasionally disappears altogether, leaving a much more complicated field with many poles all over the planet. When the dipole comes back into force, the north and south poles can swap places.
The last reversal happened about 780,000 years ago, over a period of several thousand years. Now Gauthier Hulot from the Institute of Earth Sciences in Paris and his colleagues think they have spotted early signs of another reversal.
South African anomaly
They used data from the Ørsted satellite to study strange variations in the Earth's magnetic field. In particular, one large patch under South Africa is pointing in the opposite direction from the rest of the Earth's field and has been growing for hundreds of years.
The anomalies have already reduced the overall strength of the planet's magnetic field by about 10 per cent. If they continue to grow at the same rate, the Earth's dipole will disappear within just two millennia.
But Ørsted is the first satellite to take a snapshot of the Earth's magnetic field for 20 years, and such scant data makes it difficult to predict future shifts.
"We can't really tell what will happen," says Hulot. "But we speculate that we're in an unusual situation that might be related to a reversal."
Journal reference: Nature (vol 416, p 620)
I hate when that happens.
Why should we care? Especially, since it's over several millennia. Does this affect us today? Now?
Is the sky falling?
Who cares? All life will have perished due to global warming by then.
Nothing will stick to your refrigerator.
Nah. Just that your bathwater will swirl the other way when it goes down the drain.
It could also mean the Cubs will win the World Series in the near future....
Mark W.
All the AC current will flow backwards the other half of the time though.
It will now have to be described as a cosine curve.
Any biophysicists here have a more informed idea?
Its now moving away from its (former) Hudson Bay location at a rate now exceeding several hundred kiometers - PER YEAR, if I recall the reference correctly.
D**m Canadians couldn't keep Gretzsky where he belongs, and now they're losing the North Pole!
Nah. The English drive on the wrong side of the road already. It almost causes a polar shift but we haven't hit critical mass yet.
t could also mean the Cubs will win the World Series in the near future...
Now that is stretching things a bit. But it could cause their synapses firing the other way and that would be fun to watch.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.