New research suggests the Earth's poles could flip within the period of a human lifetime.
Researchers determined a magnetic reversal, that took place 786,000 years ago, may have occurred over the course of only about a century, UC Berkeley reported.
"It's amazing how rapidly we see that reversal," said UC Berkeley graduate student Courtney Sprain. "The paleomagnetic data are very well done. This is one of the best records we have so far of what happens during a reversal and how quickly these reversals can happen."
The Earth's magnetic field is believed to be decreasing 10 times faster than usual, suggesting one of these pole switches is coming in as soon as within a few thousand years.
In the past these types of reversals have had little effect on living creatures, but could destroy our electrical grid and generate currents if it happened today. The magnetic field also protects us from harmful radiation from the Sun, and humans could see a significant increase in cancer rates if this protection is weakened.
To make their findings the researchers took measurements of the magnetic field alignment in the lake sediment in the Sulmona basin of the Apennine Mountains east of Rome, Italy. The team used argon-argon dating, often used to determine the age of rocks, to examine layers of ash above and below this sediment.
Through this method the team was able to determine the date of the Matuyama-Brunhes transition, which they believe occurred 786,000 years ago.
"What's incredible is that you go from reverse polarity to a field that is normal with essentially nothing in between, which means it had to have happened very quickly, probably in less than 100 years," said Paul Renne, director of the Berkeley Geochronology Center and a UC Berkeley. "We don't know whether the next reversal will occur as suddenly as this one did, but we also don't know that it won't."
The findings were published in the November issue of the Geophysical Journal International.
