The Earth's magnetic poles are a component of the planet's geomagnetic field, arising from the movement of molten iron and nickel flows around the central solid core, due to currents in the ionosphere, local anomalies of the earth's crust, etc. The magnetic pole is recognized as a point at which the geomagnetic field is at right angles to the surface of the planet. In total there are two poles - north and south, which are not antipodal due to the asymmetry of the field.
The magnetic pole of the Earth in the northern hemisphere is essentially the south, because. this is where the field lines go below the surface. And the "true" north pole is in the south, where these lines emerge from under the surface.
It is assumed that mankind has known about the existence of magnetic poles for a very long time. Already in 220 BC, images of the first compass, which was called the "heavenly table", were made in China. It was a small spoon rotating in the middle of a bronze plate. The exact coordinates of where the north and south magnetic poles of the Earth are located were established in the thirties and forties of the XIX century. In 1831 the Ross brothersdetermined that the north pole is at 70 degrees 5 minutes north latitude and 96 degrees 46 minutes west longitude. And the south magnetic pole has the following coordinates: 75 degrees 20 minutes south latitude and 132 degrees 20 minutes east longitude (established in 1841). As of the beginning of the 21st century, the location of these points has changed significantly. The north magnetic pole of the Earth "left" from the point determined in 1831 by 1340 km, and the south - by 1349 km (from the location of 1841, respectively). The trajectory of movement of these points is not linear - they can also perform return actions.
In recent years, scientists have noted that the displacement of the Earth's magnetic poles has accelerated significantly. Some attribute this to the fact that in 1969-1970. there was a geomagnetic jump, which significantly changed the parameters of the planet's field. Further, the correction of the location of the coordinates was carried out under the influence of the jumps of 1978 and 1991-1992. In addition, the Earth's magnetic pole is influenced by the overall strength of the field, which has fallen to a minimum value over the past century. In this regard, there are assumptions about a possible reversal of the poles, when they change places, which will cause numerous destruction and natural disasters. Over the past two million years, the change of poles has already taken place about 20 times, of which the last one fell out for a period of about 0.8 million years ago. However, no one can predict exactly when this will happen next time, because. all previous events were irregular.
In the course of research in 1993, conducted with rocks from the bottom of the Pacific Ocean, it was found that after a polarity reversal, the magnetic field first receives a maximum charge, and then its strength gradually wanes. Perhaps this is some kind of universal mechanism that makes it possible to strengthen the protection of life on the planet from cosmic radiation. Without it, our Earth would be lifeless, like Mars, where there is a very weak field, or like Venus, where it does not exist at all.
