The magnetic poles of Earth have changed often in the planet's history. And there are many indications that the planet is preparing for another shift.
The evidence is in every clay pot that was ever fired. During high-temperature baking, iron materials in clay record the exact state of Earth's magnetic field at the precise moment. By examining pots from prehistory to modern times, geologist John Shaw of the University of Liverpool in England has discovered how the magnetic field has weakened. "When we plot the results from the ceramics," he says, "we see a rapid fall as we come toward the present day. The rate of change is higher over the last 300 years than it has been for any time in the past 5,000 years. It's going from a strong field down to a weak field, and it's doing so very quickly."
No one is sure what will happen.
The field could weaken such that the poles suddenly flip polarity--that is, compasses begin to point to the south magnetic pole. Reversals are unpredictable. They come at irregular intervals averaging about 300,000 years; the last one was 780,000 years ago, making us long overdue.
Scientist Gary Glatzmaier of the University of California at Santa Cruz has observed such reversals as they occur in computer simulations. These virtual events show striking similarities to the current behavior of Earth's magnetic field and suggest we are about to experience another reversal. However, reversals take a few hundred to a few thousand years to complete. "During that time it just gets more complicated," says Glatzmaier. "Magnetic lines of force near the 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."
Of course, since the last magnetic field shift occurred over 780,000 years ago, none of us really knows what happens to humans. But the real magnetic shift will happen over long periods of time, allowing humans to adapt their bodies to a new environment.
The greatest danger of a magnetic pole shift is the breakdown in the magnetic shield that protects us from solar radiation. There is evidence that the shield is not likely to disappear but simply to have weak spots, even holes, that may allow more than normal radiation to penetrate to the surface in a few places. Scientists have presented detailed information about this on the PBS NOVA program Magnetic Storm, originally aired November 18, 2003, but often re-aired. A DVD of this program is available at: http://shop.wgbh.org
Source: Ancient Mysteries newsletter, www.EdgarCayce.org