18:54 08 February 2017
A recent study involving ancient trees in California has revealed evidence of ‘abnormal solar activity’ that took place in 5480BC. Researchers discovered high amounts of carbon-14 in the tree rings which they say could have been the result of a change in the sun’s magnetic activity.
The international team went to California where they measured carbon-14 levels in ancient trees that can live for thousands of years.
AJ Timothy Jull of the University of Arizona said: ‘We measured the 14C levels in the pine sample at three different laboratories in Japan, the US, and Switzerland, to ensure the reliability of our results,’
‘We found a change in 14C that was more abrupt than any found previously, except for cosmic ray events in AD 775 and AD 994, and our use of annual data rather than data for each decade allowed us to pinpoint exactly when this occurred.’
Their analysis suggests that there could have been a series of strong solar bursts and fluctuations in solar magnetic activity or the sun may have been in an ‘unknown phase of grand solar minimum’ during that time.