Natural disaster: A pole shift 42,000 years ago led to mass extinctions

Massive electrical storms, “auroras” around the world, UV extremes, global climate and environmental changes with mass extinctions: what people suffered 42,000 years ago seemed to be the end of their days. The driving force behind the dramatic events has been the recent reversal of Earth’s magnetic field to date, which is called pole shift. Over the course of 800 years, the North and South Poles swapped positions, reducing Earth’s magnetic field to 28 percent of its current strength.

But even more exciting was the time before the polarity reversal, when the magnetic poles moved across the Earth. Our planet’s magnetosphere collapsed to zero to six percent of its current strength during this phase known as the “Adam’s Event”. Describing the situation 42,000 years ago, Chris Tourney, a professor at the University of New South Wales, says: “We had no magnetic field at all – our cosmic ray shield has completely disappeared.”

Turney is a major one in A study published in the Journal of ScienceWhich, for the first time, accurately documented the time and environmental impact of the recent magnetic pole shift. This is made possible thanks to ancient Kauri trees from New Zealand, which have been preserved in sediments for more than 40,000 years. With their help, it is possible to determine the content of radiocarbon in the atmosphere, which resulted from the collapse of the Earth’s magnetic field. By carefully analyzing the rings of the kauri tree, the researchers were able to create a detailed timescale of how Earth’s atmosphere changed during this time.

The researchers then compared this timescale to records of environmental changes in caves, ice core and peat swamps around the world. With the help of global climate models, they discovered that the growth of ice sheets and glaciers in North America, but also major shifts in wind belts and air pressure in the Earth and in tropical storm systems can be traced back to “Adams”.

One of the first clues the researchers provided was the simultaneous extinction of megafauna on mainland Australia and Tasmania 42,000 years ago. Around the same time, Australia’s environment changed into the predominantly arid form of the dry desert and steppe known today. Evolutionary puzzles such as the extinction of Neanderthals and the sudden appearance of plastic art in caves around the world, according to the study’s authors, may be traced back to an “Adam event.”

With the magnetic field disappearing, the cosmic radiation, which unimpeded into the atmosphere, ripped apart air molecules, separating electrons and the emitted light, Torne explains: The “buzz” of ionized air has triggered the ozone layer and triggered a wave of climate change around the world. . “Sparkling plays of light can be seen all over the world. But the result has also been frequent electrical storms and an intense increase in UV values.”

The study authors believe the massive environmental changes prompted early humans to seek more protection in the caves. It could also explain the sudden appearance of cave paintings around the world some 42,000 years ago. According to study co-author Professor Alan Cooper of the Museum of South Australia, the sharp rise in UV values ​​during solar flares could turn caves into valuable shelters: “It could be that the idea of ​​a widely spread cave drawing of ocher red handprinting is out there. Using it as sunblock, a technique that some groups still use today.

People today can at least withdraw to their permanent homes. But they won’t have much fun there. “If a similar event occurs today, the consequences will be dire for modern society. The incoming cosmic rays will destroy electrical power and satellite networks,” warns Tierney.

However, according to some scientists, the terrifying vision of an impending pole reversal isn’t exactly perfect. They are anxiously watching the current rapid movement of the North Magnetic Pole across the Northern Hemisphere. “This velocity – plus the Earth’s magnetic field has weakened by about 9% in the past 170 years – could indicate an impending reversal,” explains Terney’s colleague Cooper.