Earth's magnetic polarity shifted several thousand years ago and it was an event that happened faster than expected, a new research conducted in Chinese caves on stalagmites has found.
Researchers from China, Taiwan and Australia have described their study of stalagmites in a cave in China in a release and in it, they explain how so far, modern humans have experienced the reversing polarity of Earth's magnetic field only once, but even that was long before there was any electronics or satellites in orbit. Thousands of years back, they might not have even noticed the flip.
Now in modern times, magnetic field reversal might be troublesome and interfere with everyday life. Electronic devices like mobile phones, GPS enabled devices and satellite-reliant technology could be thrown out of whack. That is one of the reasons why scientists are keen on studying past reversals; to try and predict when it might happen next.
For this, researchers reportedly travelled to the Sanxing Caves in Guizhou Province, southern China. In the caves, the samples of stalagmite columns — pillar-like deposits of salts from floor caves up — are known to contain evidence of changes that the magnetic field might have gone through going back several thousand years, reports Phys.org.
Earth's magnetic field, notes the release, is generated by the intensely hot, ball of liquid metal churning at the planet's core. It is at depths of about 2,735 km deep below the surface. This churning of molten metal can go through small changes and this will invariably affect the magnetic field. Previous research suggests that a complete reversal is likely to take many thousands of years to complete.
This new study's results, however, suggest that the Earth's magnetic field reversal can happen in as few as 100 years.
The stalagmite sample taken from the caves had a record of a magnetic field reverse happening between 107,000 and 91,000 years ago. This is a span of just 16,000 years. High-resolution cryogenic magnetometers were used to precisely study the stalagmite samples carefully, notes the report, and as a result, researchers traced changes in magnetic fields a lot more precisely than any previous study.
Through the study, the team found that around 98,000 years ago, there was a magnetic field reversal that happened just over a time period of a century and a half. This is, say the researchers, roughly 10 times faster than what scientists believed possible on Earth.
