From time to time, the magnetic poles of the Earth change places. In the entire history of the Earth, this happened a few hundred times as indicated by geological data. The last inversion of poles occurred about 781 thousand years ago.
No periodicity was found in the inversses of the magnetic field of the Earth. Sometimes it occurs very often — at intervals of several tens of thousands of years, and sometimes the magnetic field remains unchanged for millions of years.
Many scientists believe that now we are at the early stage of the new inversion of the magnetic field of the Earth.
The magnetic field both on Earth and on other planets is generated
Inversion of the magnetic field is also due to internal convection processes in the kernel. Most of the time positively and negatively charged parts of the land core are stable in the area of rotation poles, however, from time to time, unpredictable convection processes can derive them from equilibrium and then inversion of poles is possible.
At the same time, a disturbed equilibrium of charged parts of the nucleus both lead to inversion and simply to temporary disturbances of the magnetic field and return to the previous state. This has already happened about 41 thousand years ago.
Inversion of magnetic poles does not mean the end of the world or a global catastrophe. Thus, for example, no connection was established between the inversions of the magnetic field and the mass extinction of animals or plants: the inversion affects the biosphere quite a little.
Some believe that changing magnetic poles can affect the movement of continents, which will lead to massive earthquakes and tsunami. It certainly could lead to essential human victims. However, the analysis of data on the change of poles in the past does not find evidence that it was accompanied by such disasters.
In addition, seismic activity is due to the processes in the land mantle, and not in the core. The mantle is of course contact with the core, however, millions of years will be required, so that changes in the kernel affect the mantle and tactonics of the plates.
Some danger inversion of the magnetic field still carries. Firstly, during the inversion, the magnetic field of the Earth can relax and as a result, a larger amount of solar radiation will reach the surface. This may lead to an increase in the number of cancers and genetic mutations among newborns.
Secondly, the increase in solar radiation may affect the operation of electronics. If this happened instantly, then the technological collapse would probably be waiting for us, when all or a significant part of the electronics would fail, but this will occur gradually for hundreds of years and will be expressed in an increasing number of electronics faults. We will have time to react by upgrading power grids and electrical appliances, so this should not lead to any catastrophes.
Thus, once again, I note that the change of magnetic poles of the Earth has already happened more than once and many times will occur. At the same time, inversion does not entail any global catastrophes. At the time of inversion, the amount of solar radiation of the reaching surface may increase, but this increase will occur very slowly according to human standards.
Some data show that maybe we are now at the very beginning of a new inversion, which can take from 100 to 1000 years.