There is a continuation of a unsafe trend.
Earth's magnetic field serves as a shield against hazardous radiation from space, especially the Sun's charged particle flux. The scientists can, however, not say how long today's anomaly will persist. Based on a reconstruction of the Earth's magnetic field of the past, scientists from the Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences and the Universities of Iceland, Liverpool, and Nantes now show that the anomaly is probably not a precursor of a switching of the poles.
"Our research suggests instead that the current weakened field will recover without such an extreme event, and therefore is unlikely to reverse", said Richard Holme, a co-author of the study. The quality and structure of the Earth's magnetic field has changed at various circumstances all through land history.
The position of the poles and the direction of the compass needle is a permanent feature of the planet. Within their new study, published in Proceedings of the National Academy of Sciences of the United States of America PNAS, the scientists reconstructed past changes in Earth's magnetic field using paleomagnetic data from sediment cores and volcanic rocks from across the globe.
Two years ago, geologists from the University of Rochester (USA) made an wonderful discovery, they were able to detect extremely unusual magnetic anomaly in South Africa from the banks of the Limpopo river, where the magnetic field strength fell sharply and fallen to critically low values in the XIII-XVI centuries of our era. For example, about 40 thousand years ago, the North needle of a compass would point to the South pole and South to North. As it turned out, the Earth's magnetic field drastically weakened at this point of Africa at least three times during the fall of the Roman Empire and at the beginning and end of the Middle ages.
It has been suggested that due to the weakening of the magnetic field over the last two hundred years, the Earth's poles could flip at any moment.
To do this, scientists have collected samples of minerals, occurred shortly before these disasters, and checked which side was "rotated" field, trapped in crystals of iron and other magnetic materials in the strata of these rocks.
A study of the most recent near-reversals of the Earth's magnetic field by an global team of researchers, including the University of Liverpool, has found it is unlikely that such an event will take place anytime soon.
Most likely, the field strength will continue to fall for another few centuries or thousands of years, after which it will smoothly start to grow, without causing large-scale changes in the bowels of the Earth. Where it leads and when it will begin, geologists do not yet know.