The flip of the Earth's axis will occur after the strength of the planet's magnetic field drops by another 90%, which may happen in the next few centuries, physicists from France and Denmark say.
The position of the poles and where the compass needle points were not always the same as today. Periodically, about once every 450 thousand or a million years, the North and South poles of the Earth change places, traces of which scientists have found in the structure of ancient clays and volcanic rocks. Such changes are both short-term and permanent.
For example, after the last time shift of the axis, which happened about 40 thousand years ago, the north arrow of the compass pointed to the modern South Pole. In addition, about 780 thousand years ago, the poles were constantly directed in these directions, and subsequently their position changed dramatically.
Two years ago, geologists from the University of Rochester (USA) made an amazing discovery. They managed to find an extremely unusual magnetic anomaly on the territory of South Africa off the banks of the Limpopo River, where the strength of the magnetic field dropped sharply several times and dropped to critically low values in the 13th-16th centuries AD.
This first indicated that the revolutions of the Earth's poles do not occur randomly, but at special points with anomalous properties, where the mantle rocks are close to the surface and at the same time interfere with the normal circulation of matter in the planet's core. Observations of a similar point in South Africa show that this process could have already begun in the recent past.
Tuveni and his colleagues figured out how much the Earth's field must weaken for such a coup by studying samples of ancient volcanic rocks excavated from the bottom of the sea off the coast of Italy and off the island of Guadeloupe in the Caribbean.
These deposits, the researchers note, have been continuously forming over the past five million years, allowing them to track fluctuations in field strength and the direction in which its poles were directed.
To do this, scientists measured how much radioactive beryllium-10, generated in the atmosphere as a result of the interaction of cosmic rays and carbon, is present in each layer of these rocks. Accordingly, the more of this substance was present in volcanic ejections, the weaker the field was, preventing the penetration of "guests" from space.
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It turned out that during this time five complete shifts of the Earth's axis and several tens of temporary shifts of the poles occurred at once. Each of them began at a time when the field strength fell to a level ten times lower than today.
How will this affect our civilization and animals? According to geologists, such a drop in the strength of the magnetic field will disable the entire satellite constellation, deprive the ISS or alien colonies of earthlings of communication with the "big homeland" and lead to the bombardment of the Earth by cosmic rays and radioactive elements.
They can simply accelerate the evolution of life and increase the likelihood of developing cancer, or completely destroy all flora and fauna. Further excavation and observation of field fluctuations using satellites will help to understand which of these scenarios will be closer to the truth, scientists conclude.