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The history of the Earth suffered a turning point 42,000 years ago, when a reversal of the magnetic poles caused a breakdown of the magnetic field, causing major environmental changes and mass extinctions, according to a study released Friday.
Research from the Australian University of New South Wales and the Museum of South Australia, published in the journal Sciences, points out that this event was caused by a reversal of the Earth’s magnetic poles, combined with the change in the solar winds, which produced electrical storms, extensive auroras and cosmic radiation.
“For the first human beings who had to live that moment it must have seemed ‘the end of days'”, considered one of the authors, Alan Cooper, of the Museum of South Australia.
The researchers, who dubbed this period the Adams Event, suggest that it may explain evolutionary mysteries, such as the extinction of Neanderthals or the sudden appearance of figurative art in caves around the world, considering that humans had to seek new shelters.
Although scientists already knew that the magnetic poles changed about 41,000 / 42,000 years ago (known as the Laschamps Event), they did not know exactly if and how it affected life on Earth.
Study co-author Chris Turney, from the University of New South Wales, noted that the research allowed for the first time “accurately” dating the timing and environmental impacts of the last magnetic pole shift.
The ancient kauri trees of New Zealand, which have remained in sediment for more than 40,000 years, have given clues to researchers, who, through growth rings, were able to measure and date the maximum levels of atmospheric radiocarbon caused by the magnetic collapse and created a detailed timescale of how the atmosphere changed.
The researchers compared this timescale with records from locations across the Pacific and devised global climate models to find that the growth of North America’s ice sheets and glaciers and major changes in winds and tropical storm systems they go back to the Adams event.
One of the first clues was that the megafauna of mainland Australia and Tasmania suffered a simultaneous extinction 42,000 years ago.
The magnetic poles of the Earth have a natural dislocation, but sometimes, for reasons that are not clear, these movements can be more drastic and about 42,000 years ago they moved completely.
