Some 42, years ago, in an event known as the Laschamp Excursion, the poles did just that for around years, before swapping back -- but scientists were unsure exactly how or if it impacted the world.
Earth's magnetic north pole is heading for Russia and scientists are puzzled. Now, a team of researchers from Sydney's University of New South Wales and the South Australian Museum say the flip, along with changing solar winds, could have triggered an array of dramatic climate shifts leading to environmental change and mass extinctions. Scientists analyzed the rings found in ancient New Zealand kauri trees, some which had been preserved in sediments for more than 40, years, to create a timescale of how Earth's atmosphere changed over time.
Read More. Evidence suggests that, for hundreds to thousands of years at a time, our planet has had four, six, and even eight poles at a time. This is what has happened when the magnetic poles flipped in the past. And when it happens again, it won't be good news for humans.
Now you might think, eight poles must be better than two. But the reality is that: Multiple magnetic fields would fight each other. Earth's magnetic field is what shields us from harmful space radiation which can damage cells, cause cancer, and fry electronic circuits and electrical grids. With a weaker field in place, some scientists think this could expose planes to higher levels of radiation, making flights less safe. This could also disrupt the internal compass in many animals who use the magnetic field for navigation.
Even more extreme, it could make certain places on the planet too dangerous to live. But what exactly will take place on the surface is less clear than what will undoubtedly happen in space. Satellites and crewed space missions will need extra shielding that we'll have to provide ourselves. Without it, intense cosmic and solar radiation will fry circuit boards and increase the risk of cancer in astronauts. Our modern way of life could cease to exist.
But carrying out measurements on these archeological artifacts is difficult. For one, the magnetism in ancient objects is very weak — not enough to move a compass needle. And if any objects were heated and cooled several times, several magnetic patterns will be superimposed. Lastly, their reliability is dependent on the objects remaining in the same location that the heating took place. Despite these difficulties, researchers have largely mapped modern changes in the magnetic field beneath western Europe and the Middle East.
Juvenile loggerhead turtles dig their way out of underground nests on the beaches of Florida, enter the sea and travel far into the Atlantic Ocean sometimes completely traversing it. Then, after many years, they return to the same Florida beaches on which they were born. They navigate this featureless, 9,mile 14,km journey by detecting the strength and direction of the magnetic field.
Additionally, Earth is constantly bombarded with a stream of charged particles arriving from the Sun and cosmic rays, mostly protons and atomic nuclei, from deep space. In the period leading up to a reversal, the magnetic field becomes weaker and significantly less effective at shielding us from those particles. While some geologists note that mass extinctions seem to correlate with these time periods, humans or our ancestors have been on Earth for several million years.
During that time there have been many reversals, and there is no obvious correlation with human development. The direct effect on mankind could be only slight, but not so for technology.
We use artificial satellites for navigation, television broadcasting, weather forecasting, environmental monitoring and communication of all kinds. Without the protection of a magnetic field, these satellites could be seriously disrupted by solar wind or cosmic rays colliding with electronic circuits. Recent geological studies have suggested a possible reason for the anomaly. It is widely believed that our Moon was formed when Earth was struck by the planet Theia 4. It now appears that the remains of Theia may lie beneath our feet.
Scientists suggest that these rock masses are the missing remains of Theia and that they interfere with the convection of molten iron — giving rise to the weak magnetic field in the South Atlantic. Why it's so hard to treat pain in infants. This wild African cat has adapted to life in a big city. Animals Wild Cities This wild African cat has adapted to life in a big city Caracals have learned to hunt around the urban edges of Cape Town, though the predator faces many threats, such as getting hit by cars.
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