Australian scientists have found signs that the reversal of the Earth’s magnetic poles 42,000 years ago caused previously unknown catastrophic climate changes, which, in turn, led to a mass extinction. This is reported in an article published in the journal Science.
The researchers dubbed the event the Adams’ Geomagnetic Transition Event, after science fiction writer Douglas Adams, author of The Hitchhiker’s Guide to the Galaxy. It was caused by the displacement of the Earth’s magnetic poles and changes in solar activity. It was dated by the remains of New Zealand cowrie (southern agatis) trees, which captured in their tree rings a burst of radiocarbon in the atmosphere caused by the collapse of the Earth’s magnetic field.
Scientists also found that the rise of ice sheets and glaciers in North America and global changes in winds and tropical storms coincide with the Adams event. At the same time, the mass extinction affected the megafauna (large animals) of Australia and Tasmania, when the habitat became more arid. The authors of the work also associate global climate change with the disappearance of Neanderthals.
During the event, the Earth’s magnetic field almost completely disappeared, while the Sun entered the phase of minimum solar activity, which simultaneously enhances the effect of cosmic rays. As a result, the ionization of the outer layers of the atmosphere increased, and auroras began to appear more often in lower latitudes. Perhaps the changes forced people to seek refuge in caves, which was the impetus for the development of rock art.