The directionally challenged may find a new curveball thrown their way, as researchers reveal that in our lifetime we may see flip in what we know to be North and South. For those who know their way around navigating the wild, seeking directions in the stars, or even reading the face of a compass, you may have to reconsider the norm or repaint the stars to fit a changing magnetic field that may soon have Antarctica pointing North.
Shifts in the Earth's magnetic field is not a new discovery, rather it's something scientists have observed for years. It fact, it is estimated that roughly 800,000 years ago, what we consider to be North and South were reversed. And over the course of its lifetime, the Earth has flipped its magnetic field a handful of times, though the occurrence is rare on a human scale of time.
It's a process researchers believe begins with a weakening in the field prior to the inversion of the poles, similar to the state the Earth's magnetic field is currently in. And with new evidence pointing that the inversion of the poles only took 100 years to occur the last time the Earth turned topsy turvy, some researchers are questioning whether we may seen an inversion in our lifetime as well.
"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" lead author and director of the Geochronology Center at UC Berkeley, Paul Renne says.
The new study, published this upcoming November in the newest issue of Geophysical Journal International, analyzed new data collected this past summer by a European Space Agency (ESA) satellite orbiting the Earth. And what they found is that evidence suggests the Earth's magnetic field is weakening 10 times faster than researchers originally estimated.
And while the Earth's current magnetic state was analyzed from space, to discover the conditions leading to the reversal that happened nearly 786,000 years ago the researchers looked deeper into the Earth's crust for a hint at an answer.
Renne and a team of researchers dug through sediments left behind by an ancient lake at the base of the Apennine Mountains in Italy for a trace of evidence. Mixed into the sediment lies ashen layers from previous volcanic eruptions, ash made of magnetically sensitive minerals that allowed the researchers to find the direction the magnetic field once pointed before the ash was embedded in sediment. Then, utilizing argon-argon dating, wherein radioactive K-40 decays into Ar-40 at a specific rate, the researchers were able to pinpoint the inversion of the magnetic field with great accuracy over the 10,000 year span the sediments were composed of, dating the flip to roughly 786,000 years ago.
"It's amazing how rapidly we see that reversal" UC Berkeley graduate student, Courtney Sprain says. "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."
