The magnetic field of the earth can run much faster than previously thought




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Our sun emits a constant stream of radiation and particles into space. Fortunately, the magnetic shield of the Earth protects most of this solar bombardment from the surface. This field changes constantly in intensity and can even change direction – changing the magnetic north pole in the magnetic south pole and vice versa.

Delivery of the artist from the magnetosphere of the earth.NASA

The last complete geomagnetic reversal occurred about 780,000 years ago. Modern geomagnetic measurements have shown that the magnetic field of the earth fades rapidly, by almost 16 percent since 1840. It is still unclear what the observed changes control and whether such changes are a sign that a complete magnetic reversal will take place soon, such as suggested by some researchers. While studying past geomagnetic changes, as preserved in the history of igneous rocks, most scientists assumed that a complete magnetic pole shift should last several centuries to several thousand years.

A research team from the University of Taiwan has now been published A study suggesting that the magnetic field of the earth can change direction much faster than previously thought. The team studied the annual growth days of a stalagmite in the Sanxing cave, located in southwestern China.

The sampled stalagmites and stalactite formations in the Sanxing cave, China.Chou et al. / PNAS

The 3-inch long core covers about 16,000 years. The scientists analyzed the magnetic properties of the individual layers and discovered two phases with a weaker magnetic field, between 105,000 and 103,000 and 98,000 to 92,000 years ago. During the more recent phase, the magnetic north pole "moved" from Alaska to a place in the Antarctic Ocean. What stunned the scientist was the speed of this almost complete reversal, apparently only 144 years, with a few decades as a margin of error of the radiometric dating technique used. & Nbsp;Then the magnetic field switched back to the "normal", modern polarity.

Magnetic field variability and inclination as measured in the 95,000-year-old cave deposits.Chou et al. / PNAS

although disaster movies Imagine a grim fate for life on Earth when the magnetic field flip-flops of the planet, in reality there seems no correlation between magnetic reversals and extinction rates. & nbsp; Even during a complete reversal, the magnetic field not only completely disappears. Residual magnetism still offers some protection and the atmosphere of the earth alone is sufficient to protect life from the most harmful effects of space radiation. Modern electronics & nbsp; – both on the surface of the earth and in the track & nbsp; – there is still a high risk of interference and jamming due to particles and radiation. A pole shift can not be predicted (despite claims on social networks), since magnetic reversals have been randomly distributed over time in the past. In some periods the earth's magnetic field changed every 20,000 years, but with a number of periods of constant polarity lasting millions of years. Nonetheless, as the paper suggests, if significant magnetic disturbances can really take place in just a century, this poses new challenges for our civilization, because the technology should be ready to deal with such changes.

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Our sun emits a constant stream of radiation and particles into space. Fortunately, the magnetic shield of the Earth protects most of this solar bombardment from the surface. This field changes constantly in intensity and can even change direction – changing the magnetic north pole in the magnetic south pole and vice versa.

Delivery of the artist from the magnetosphere of the earth.NASA

The last complete geomagnetic reversal occurred about 780,000 years ago. Modern geomagnetic measurements have shown that the magnetic field of the earth fades rapidly, by almost 16 percent since 1840. It is still unclear what the observed changes control and whether such changes are a sign that a complete magnetic reversal will take place soon, such as suggested by some researchers. While studying past geomagnetic changes, as preserved in the history of igneous rocks, most scientists assumed that a complete magnetic pole shift should last several centuries to several thousand years.

Now a research team from the University of Taiwan has published a study suggesting that the earth's magnetic field can change direction much more quickly than previously thought. The team studied the annual growth days of a stalagmite in the Sanxing cave, located in southwestern China.

The sampled stalagmites and stalactite formations in the Sanxing cave, China.Chou et al. / PNAS

The 3-inch long core covers about 16,000 years. The scientists analyzed the magnetic properties of the individual layers and discovered two phases with a weaker magnetic field, between 105,000 and 103,000 and 98,000 to 92,000 years ago. Moved during the more recent phase & # 39; the magnetic north pole moves from Alaska to a place in the Antarctic Ocean. What stunned the scientist was the speed of this almost complete reversal, apparently only 144 years, with a few decades as a margin of error of the radiometric dating technique used. Then the magnetic field switched back to the "normal", modern polarity.

Magnetic field variability and inclination as measured in the 95,000-year-old cave deposits.Chou et al. / PNAS

Although disaster films represent a grim fate for life on Earth when the magnetic field flip-flops of the planet, there seems to be no correlation between magnetic reversals and extinction rates. Even during a complete reversal, the magnetic field not only completely disappears. Residual magnetism still offers some protection and the atmosphere of the earth alone is sufficient to protect life from the most harmful effects of space radiation. However, modern electronics – both on the surface of the earth and in an orbit – still have a high risk of interference and jamming due to particles and radiation. A pole shift can not be predicted (despite claims on social networks), since magnetic reversals have been randomly distributed over time in the past. In some periods the earth's magnetic field changed every 20,000 years, but with a number of periods of constant polarity lasting millions of years. Nonetheless, as the paper suggests, if significant magnetic disturbances can really take place in just a century, this poses new challenges for our civilization, because the technology should be ready to deal with such changes.


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