The Earth’s magnetic field is gradually weakening, scientists have found. Especially quickly it occurs on the site, stretching from Africa to South America. Data came from a series of satellites of the European space Agency Swarm. The anomaly has puzzled geophysicists and caused some technical irregularities in the near-earth spacecraft, reports the European Space Agency.
The magnetic field is vital for our planet. It protects us from cosmic radiation and charged particles from the Sun.
The main magnetic field source is in a liquid outer core containing layers of molten iron. The core is located at a depth of three thousand kilometers below the surface.
It is known that the magnetic field is unstable. Several times in the history of the Earth North and South poles fully reversed Studies have shown that changes not only the direction but also the power of the field.
So, for the last 200 years the magnetic field on average has lost about 9% of their power on Earth. And between Africa and South America formed a large area of low magnetic intensity. Scientists called it the South Atlantic anomaly.
From 1970 to 2020, the minimum field intensity in this region decreased from about 24 000 to 22 000 nanotesla. At the same time, the area of the anomalous zone has grown. It was expanding to the West at a speed of about 20 km per year.
New data showed that southwest Africa was a second center of minimal activity. Scientists have suggested that South Atlantic anomaly can be split into two independent cells.
The appearance of the second minimum does not fit into accepted theory of the formation of the magnetic field of the planet. Scientists have concluded that this process is much more complicated than they expected.
It is noted that the weakening of the magnetic field is safe for those who is at the surface. But satellites flying over these areas at high altitude, with a high probability will encounter technical problems.
The causes of the anomaly remain unknown. Perhaps the magnetic field is weakening because the poles are getting ready to switch places again (this happens on average every 250 thousand years). But this is only a theory. Scientists continue to document changes using satellite data and hope to better understand the processes occurring deep in the bowels of the Earth.
Earlier it was reported that our scientists, the reason for the rapid migration of the North pole from Canada to Siberia. According to them, this is due to changes in the flow of the molten material within the Earth.