Compasses may point south

In the future your compass could become obsolete. The needle instructing you of the north, will in fact be pointing south, and vice-versa. That, at least, is what will happen in a few thousand years when the earth's magnetic field undergoes a reversal.

Researchers, who published their findings in the journal Nature, are claiming that they have seen evidence pointing to the beginning of a complete reversal of the Earth's magnetic poles.

Gauthier Hulot of the Institut de Physique du Globe de Paris studied satellite data from 20 years ago, in comparison with data from the present, in order to make this prediction.

Upon examination of the motion of the Earth's liquid core off the southern tip of Africa as well as the North Pole, anomalies were found. While the general westward rotation normally observed was still in place, the iron which was supposed to be flowing down to the center was flowing upwards, and vice-versa.

The earth's magnetic field is generated by the motion of the earth's liquid core, the 'geodynamo'. Thus these magnetic flux reversals seen off of Africa and the North Pole are disconcerting.

According to Hulot, "The present rate of change is not tremendous, but it's still quite worrisome."

While polarity reversal isn't unheard of, it is not a frequent event. The last reversal occurred 780,000 years ago, after the island of Hawaii was formed.

What is unusual, Hulot commented, is that previously reversals "happened much more often, every 100,000 years or even 50,000 years."

Thus, this reversal comes as "an amazingly rapid change" according to geophysicist Peter Olson of Johns Hopkins University.

Currently, the Earth's magnetic north is located near Ellef Ringnes Island in the Canadian Arctic, while the magnetic south pole is off the coast of Antarctica. So how soon is that going to change?

According to Dr. Olson, at least not until "early in the next millennium."

However, the switch isn't quite instantaneous. As the earth's poles begin to switch, our planet's magnetic field will weaken to approximately one-tenth its strength for about 3,000 years.

Eventually the magnetic field will power itself back up to full strength, but reversed.

As Dr. Hulot points out, "all of the Earth is protected from charged particles from the sun thanks to the Earth's magnetic field, and these particles could be dangerous not only to satellites but to life".

No real need to fret though. Unless you're a satellite, astronaut or animal that relies on the magnetic field for navigation, the pole reversal should have no effect on you or your ancestors.

Even if you do fall into one of the above categories, you'll likely only experience disorientation now and then.