Sunday, December 21, 2003

FILE UNDER “ONE MORE THING TO WORRY ABOUT”

I have heard about this before on the websites and in the small press publications of the extremely paranoid, who seem to think that this situation would bring down every computer, communications device, and even simple electric motors, and plunge us all back into a new and probably well deserved stone age. I even wonder what it might do to the pick-ups on the average Stratocaster.

EARTH'S POLES APPEAR POISED TO FLIP

Article Published: Friday, December 12, 2003
By Douglas Fischer Oakland Tribune

SAN FRANCISCO - The Earth's magnetic field has weakened so fast in the past 150 years that scientists suspect the planet's magnetic poles are on the verge of flipping, a chaotic process that could dot the planet with multiple poles for centuries until two stronger poles again emerge. The change would wreak havoc with satellites and navigational aids and leave the Earth exposed to blasts of charged solar particles normally deflected by a strong magnetic field. Speaking Thursday at the American Geophysical Union, an annual international scientific gathering, scientists
cautioned that much is still speculation.
Any flip of the Earth's magnetic poles would happen over several thousand years. More likely, they said, turbulent forces deep in the planet's molten core are sending an errant but not unusual "excursion" to the surface that will ultimately fade and disappear, restoring the planet's protective magnetic field."Chances are this is going to die out," said Jeremy Bloxham, chairman of the Department of Earth and Planetary Sciences at Harvard University. "Reversals are pretty rare." But history is rife with examples. The magnetic field has flipped between 200 and 300 times in the past 150 million years, based on studies of sea floor sediments.
The poles last flipped 780,000 years ago. But the rate of decay scientists are measuring is consistent with a reversal, Bloxham added. More worrisome is that a large patch over the South Atlantic has already reversed and is interrupting some satellites. A change wouldn't be catastrophic, at least as far as scientists can see. No mass extinctions have been tied to past reversals, said John Tarduno, a geophysics professor at the University of Rochester in New York. Typically during a reversal, the Earth loses its two traditional poles and weaker multiple poles pop up and fade away, powered by convection flows deep within the Earth's core, said Tarduno. Compasses would not point "north" but to the closest, strongest field, be it over sub-Sahara Africa or Des Moines. Then, after about 1,000 years, two stronger poles would emerge.




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