Pole Reversal Science Quicky

The geologic record shows that hundreds of pole reversals have occurred throughout Earth's history; they happen when patches of iron atoms in Earth's liquid outer core become reverse-aligned, like tiny magnets oriented in the opposite direction from those around them. When the reversed patches grow to the point that they dominate the rest of the core, Earth's overall magnetic field flips. The last reversal happened 780,000 years ago during the Stone Age, and indeed there's evidence to suggest the planet may be in the early stages of a pole reversal right now.

The geomagnetic field is currently weakening, possibly because of a growing patch of reverse-alignment in the liquid core deep beneath Brazil and the South Atlantic. According to Tarduno, the strength of Earth's magnetic field "has been decreasing for at least 160 years at an alarming rate, leading some to speculate that we are heading toward a reversal."

The reversal might happen, or it might be aborted — Earth is too complex a system for scientists to know which outcome to expect. Either way, the process will drag on over the next few thousand years, giving us time to adjust to the changes.

Full Article: http://www.livescience.com/18426-earth-magnetic-poles-flip.html