The magnetic field reliably protects the Earth from cosmic radiation and the solar wind, which is capable of destroying the gaseous envelope of the Earth. Its existence is explained by the processes occurring inside the planet with an iron core and molten metal surrounding it.
However, there are places on Earth where there is a deviation of the magnetic field strength from normal values. The concept of magnetic anomalies emerges.
About what areas of magnetic anomaly are, physics tells quite extensively. Understanding the causes of their occurrence, the possible consequences of their occurrence, as well as the patterns of physical processes in these areas is a powerful tool for studying the magnetic field and the interior of the Earth.
What are areas of magnetic anomaly
The protective magnetic field is constantly changing. When observing the Earth's magnetic field, the question of what are the areas of magnetic anomaly is relevant. Indeed, it is in such areas thatdeposits of minerals, as well as malfunctioning technical equipment.
Magnetic anomalies are areas in which there is a deviation of the magnetic field from the corresponding values in neighboring areas. Most of these phenomena are believed to be caused by underground deposits of magnetic iron ores.
The question of what areas are called magnetic anomalies also implies an understanding of the magnitude of the impact of a magnetic field with deviant parameters. Depending on the scale, such anomalies are divided into:
- Continental, whose area is from 10 to 100 thousand km2.
- Regional, occupying from 1 to 10 thousand km2.
- Local, the distinguishing feature of which, as a rule, is the occurrence of iron ore in the bowels of the earth.
The East Siberian magnetic anomaly belongs to the continental zones. And the most noticeable representative of local areas is the Kursk magnetic anomaly.
Kursk magnetic anomaly
The unusual behavior of the Earth's magnetic field in the region of Belgorod and Kursk was first noted in 1773. The cause of the anomaly in this area was the iron ore deposits discovered in the bowels of the earth. The magnetic field strength in some areas of the Kursk Magnetic Anomaly (KMA) exceeds the norm by 2-3 times.
The amount of iron in the ore basin is 50% of the world's iron ore reserves. A Kursk Magneticthe anomaly is considered the most powerful on the planet. The territory of the KMA covers an area of more than 160,000 km2, covering 9 regions of the Central and Southern part of Russia.
Brazilian Magnetic Anomaly
Inhabitants of the southern regions know firsthand what areas of magnetic anomaly are. The phenomenal Brazilian Magnetic Anomaly (BMA) is located off the Brazilian and South African coasts. The uniqueness of the BMA lies in the fact that the cause of its occurrence is the "failure" of the Earth's magnetic field.
The BMA discovery belongs to the Koro space telescope. In 2011, his measurements of proton fluxes from the Sun to the Earth indicated a region in which the particles traveled farther than elsewhere on the planet. Subsequent observations and studies have pointed to the difference in the magnetic field from normal values in the region.
BMA is the area with the weakest magnetic field. Protons here can descend up to 200 kilometers from the surface of the planet. Due to the high level of radiation over the territory of the BMA, equipment fails, aircraft, satellites and even spaceships fail. As a result of the influence of the Brazilian magnetic anomaly, space objects such as the Hubble telescope and the Phobos-Grunt interplanetary station were affected.
Strip magnetic anomalies
Considering the question of what areas of magnetic anomaly are, one cannot fail to mention the World Ocean. Along ocean ridges for hundreds and even thousandskilometers stretched so-called band anomalies having an ordered structure. The values of the magnetic field strength in such areas are above or below the norm. Such deviations are called positive or negative anomalies of the magnetic field. A similar feature of the magnetic field of the oceans is based on the spreading of the ocean crust and the magnetism of rocks.
