The Earth’s magnetic field is created by the movement of iron in the outer core. It protects our planet against harmful radiation from space. Our shield has weakened by about 10 percent in the last 200 years or so, according to Swedish scientists from Lund University. However, the currently observed anomalies in the magnetic field do not mean that we are dealing with a reversal of the poles.
The anomalies observed in some parts of the Earth gave rise to speculations about the allegedly changing magnetic poles of our planet. An analysis of the traces of this field from the last 9,000 years shows that nothing of the kind is happening, and that the anomalies will most likely disappear over time.
It weakens, but it doesn’t turn around
It has been known for a long time that the magnetic field surrounding the Earth (which, among other things, protects it from harmful radiation) is not stable. It is also known that in the past – on average every 200,000 years – its poles have reversed.
Scientists have also observed that our planet’s field has decreased by 10 percent over the past 180 years. At the same time, in the South Atlantic region, an area was created in which the magnetic field is much less powerful. This is the so-called South Atlantic anomaly.
It even caused damage to the satellites passing over this region caused by solar radiation. This has led to speculation and suspicion that the Earth’s magnetic field “tends” to reverse.
In the pages of the Monday edition of the academic journal “Proceedings of the National Academy of Sciences”, however, scientists from the University of Lund in Sweden argue that nothing is happening.
“ We have mapped changes in the Earth’s magnetic field going back 9,000 years and it turns out that anomalies such as the one in the South Atlantic are likely recurring phenomena related to changes in the strength of the planet’s magnetic field, explained Lund University geologist Andreas Nilsson.
A number of benefits
Researchers analyzed various sources of information from ancient times – burnt archaeological artifacts, samples of volcanic material and various types of sediments from lakes and seas, for example. You can read from them information about the magnetic field in a given period – both its strength and direction.
“We developed a new modeling technique that combines these indirect observations from different time periods and locations into a single magnetic field reconstruction spanning 9,000 years,” said Nilsson. Based on the similarities with the reconstructed anomalies, we predict that the South Atlantic anomaly is likely to disappear in the next 300 years and the Earth will not reverse poles, he added.
There are more benefits of the new map, note the authors of the study. Such analyzes allow for a better understanding of the processes taking place inside the planet, which cause the formation of the magnetic field. They can also allow for a more accurate determination of the time of the formation of geological and archaeological finds.
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