Enzo Campitella 5 hours ago 8 minutes
A representation of the Earth’s magnetic field. Source: NASA / Goddard Space Flight Center
Modern scientific discovery looks like something out of a movie. The reversal of Earth’s magnetic field thousands of years ago plunged the planet into an environmental crisis It could have resembled a TV disaster series. Earth’s magnetic field is dynamic and has been reversed on many occasions, when the magnetic north and south poles alternate.
In today’s world that is totally dependent on electronics, such investment could seriously disrupt communication networks.. But he also posted it Live Science The effect could be more serious. for the first time, Scientists have found evidence that polar reversal could have serious environmental ramifications. His research links the reversal of a magnetic field some 42,000 years ago with global climate change, which is causing extinctions and modifying human behavior.
Earth’s magnetosphere – the magnetic barrier that surrounds the planet – is caused by the agitation of hot molten metal around its iron core. This continuous flow of liquid generates electricity that in turn produces magnetic field lines, which curve around the planet from pole to pole, according to NASA.
How does the magnetic field work
Like a protective bubble The magnetic field protects the earth from solar radiation, Which is vital to life on this planet. On the side of the sun-facing planet, the constant bombardment of the solar wind crushes the magnetic field, extending no more than 10 times the Earth’s radius. However, on the side of the planet moving away from the sun, the field extends much farther into space, creating a huge “magnetic tail” that reaches beyond the moon.
Magnetic field and poles (geographic and magnetic)
The two points on Earth where magnetic field lines meet are the North Pole and the South Pole.. But although these positions are relatively stable, the poles – and the magnetic field itself – are not stable. Once every 200,000 to 300,000 years, the field becomes weak enough to completely reverse polarity.. The process can take hundreds or even thousands of years.
The study’s lead author, Alan Cooper, said magnetic particles preserved in volcanic sediments and other sediments tell scientists when reversals occurred in the past because these particles are in alignment with the magnetic field at the time of their deposition, indicating the location of the magnetic north pole. He is an honorary professor Department of Geology at the University of Otago In New Zealand.
Magnetic field reflections
Researchers recently wondered whether a relatively recent, brief polarity reversal, called Laschamps Excursion, which occurred between 41,000 and 42,000 years ago, could be related to other radical changes on Earth at that time that were not attributed prior to activity in the magnetosphere. The study authors noted that they suspected that during a time when our protective magnetic field was reversing and was weaker than normal, Exposure to solar and cosmic radiation can affect the atmosphere enough to affect the climate.
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Previous studies of Greenland ice core samples dating back to Laschamps have revealed no evidence of climate change. This time, however, researchers have turned their attention to another potential source of climate data: kauri trees (Agathis australis) preserved in swamps in northern New Zealand. They cut cross sections, or “biscuits”, from preserved tree trunks and Observed changes in carbon 14 levels, Which is a radioactive form of the element, during a period that included the Laschamps reflection. Their analysis revealed elevated levels of radiocarbon in the atmosphere during Laschamps, When the magnetic field is weakening.
“Once we count the exact moment from the kauri record, we can see that it matches perfectly with records of climate and biological change around the world,” Cooper said. Live Science. For example, around that time, The megafauna became extinct in Australia and Neanderthals became extinct in Europe; Their degradation has accelerated due to climate-related changes in their ecosystems.
Effects that have occurred
They may have caused widespread climate disturbances and related extinctionss. They found that a weak magnetic field, acting at 6% of its natural strength, can cause significant climate impacts “through ionizing radiation that severely damages the ozone layer, permits ultraviolet rays and changes the ways in which the energy of the ozone layer is emitted from the sun. Air “.
The red ocher handprints were made in the Spanish cave of El Castillo approximately 42,000 years ago, and it is suggested that they represent the use of an ancient form of sun protection. (Image credit: Paul Pettitt, Government of Cantabria)
The highly ionized atmosphere could also have generated bright auroras around the world and produced frequent thunderstorms.“It made the sky look similar to a disaster movie,” Cooper said. In the note, the place of publication of which was the scientific journal Science, indicates that Another important change occurred at that time in Homo sapiens, as rock art began to appear in places around the world. This included the earliest examples of hand stencils in red, now suspected It was actually a sign of sunscreen application, a practice still found in modern indigenous groups in Namibia. High levels of UV rays from a weak magnetic field may lead humans to seek refuge in caves, or force them to protect their skin with minerals that block the sun’s rays.
Scientists cannot accurately predict when the next magnetic field will reverse. However, some evidence, such as the migration of the Arctic current through the Bering Sea region, and the magnetic field itself weakened by nearly 10% in the past 170 years, suggests that The extension may be closer than we think, Which makes it all the more urgent for researchers to fully understand how large changes in our magnetic field can shape environmental changes on a global scale.