The temporary collapse of the Earth’s magnetic field 42,000 years ago caused a major crisis Climate changes that led to global environmental shifts and mass extinctions.
As a new international study co-led by the University of New South Wales (UNSW), Sydney and the Museum of South Australia showed, this dramatic turning point in Earth’s history, mixed with thunderstorms, diffuse auroras and cosmic radiation, resulted from the reflection of the Earth’s magnetic poles and the changing solar wind. The results have been published in the journal Science (also read: Researchers fly things propelled by light).
“For the first time in history, we have been able to accurately determine the timing and environmental impacts of a recent magnetic pole reflection.”Says Chris Tourney, professor at the University of New South Wales and co-lead author of the study.
Discoveries were made possible thanks to ancient New Zealand curry trees, which have been preserved in sediments for more than 40,000 years. “By using ancient trees, we were able to measure and date the increase in radioactive carbon levels in the atmosphere caused by the collapse of the Earth’s magnetic field,” Tourney said in a statement.
While scientists already knew that the magnetic poles were temporarily reversed 41-42,000 years ago, They didn’t know exactly how, if any, life on Earth was affected. But researchers were able to create a detailed timeline of how Earth’s atmosphere changed during this time by analyzing rings in ancient kauri trees.
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“Kauri trees, like Rosetta Stone, help us standardize records of environmental change in caves, ice core and peatlands around the world.”Says Associate Professor Alan Cooper, researcher emeritus at the Museum of South Australia.
The researchers compared the newly created timeline with records from locations across the Pacific and used it to model global climate, and found that the growth of ice sheets and glaciers in North America and major changes in major belts of wind and tropical storm systems could be traced back to the Adams event, which the researchers launched On British science fiction writer Douglas Adams.
It was a time when random cosmic events coincided with extreme environmental changes It is found around the world 42,000 years ago.
One of his first clues was that megafauna in Australia and Tasmania went through simultaneous extinctions during this period.
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“It never seemed to be true, because it was a long time after the arrival of the Aborigines, but around the same time the Australian environment changed to the present arid state,” says Professor Cooper. The paper suggests that this event could explain many other evolutionary mysteries, such as the extinction of Neanderthals and the sudden and widespread appearance of plastic art in caves around the world.
Colombian physicist Santiago Andres Triana of the Belgian Royal Observatory is commenting on this Reflection of magnetic poles is a phenomenon that occurred many times in the past and the exact causes of it are not fully understood.
“We know that the magnetic field is created by the dynamo effect in the basic liquid of the Earth. Currents in this ocean of liquid iron generate magnetic fields that in turn provide more energy to these currents, in a feedback process that results in a magnetic field as wide as the one we currently observe. However, this process is not completely stable, Triana says the magnetic reversal that occurred 42,000 years ago is evidence of this.
Triana adds that, “During this relatively short period of reversed polarity, the magnetic field strength was much lower than the normal intensity. This allows more radiation from the electrically charged particles from the sun to reach the surface of our planet, causing massive damage to the ozone layer, thus affecting On the climate and the environment in general. “
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According to Triana, the magnetic field is currently weakening, albeit at a relatively slow rate: “We also know that“ vibrations ”occur periodically in the magnetic field, such as the one presently seen by the rapid drift of the magnetic north pole from Canada to Siberia.
The magnetic reversal revealed by the Laschamps event, as the phenomenon described in the study is called, shows that sudden changes in the Earth’s interior can occur on a very fast (geologically) time scale and that they can adversely affect the viability of our planet. That is why it is important to study and understand the processes occurring in the Earth’s core as accurately as possible. Our future may depend on it, “Triana says.