The earth is surrounded by a magnetic field. It is what keeps the compass needle pointing north and protects our atmosphere from the constant bombardment of charged particles from space, such as protons. Without magnetic field our atmosphere will slowly disappear under the influence of harmful radiation, and life will almost certainly not be able to exist in the form that we observe today.

Geomagnetic reversals

You may think that the magnetic field is an infinite, constant aspect of life on Earth, and to some extent you would be right. But the Earth's magnetic field is actually changing. About once every few hundred thousand years or so, it flips over. The North Pole changes places with the South. And when this happens, the magnetic field also tends to become very weak.

Anomaly of the South Atlantic

Geophysicists are now alarmed by the realization that the strength of the Earth's magnetic field has been declining over the past 160 years at an alarming rate. This collapse is concentrated in a vast expanse of the southern hemisphere and extends from Zimbabwe to Chile. It is known as an anomaly of the South Atlantic. The strength of the magnetic field in this place is so weak that it even poses a danger to satellites that orbit the Earth over this area. The magnetic field no longer shields them from radiation that interferes with satellite electronics.

Consequences of the reversal of the magnetic field

But that's not all. The strength of the magnetic field continues to weaken, potentially heralding even more dramatic events, including a global reversal of the magnetic poles. Such a significant change will affect our navigation systems as well as power transmission. The Northern Lights can be seen on different latitudes. In addition, at very low field strengths, more radiation will reach the Earth's surface during the global roll, which can also affect cancer rates.

Scientists still do not fully understand the extent to which these effects will be achieved, so their research is especially relevant. They use some possibly unexpected sources of data, including 700 years of African archaeological records, to investigate the matter.

Origin of the Earth's magnetic field

Earth's magnetic field is created by the presence of iron in liquid outer core our planet. Thanks to data from observatories and satellites that study the magnetic field in recent times, scientists can accurately model what it would look like if we placed a compass directly over the Earth's swirling liquid core.

Reverse Polarity Spot

These analyzes show a striking feature: Below southern Africa, there is a patch of reversed polarity at the core-mantle interface where the liquid iron of the outer core meets the rigid part of the Earth's interior. In this region, the polarity of the field is opposite to the average global magnetic field. If we could set up a compass deep under southern Africa, we would see that in this unusual area, the arrows that indicate north actually point south.

This slick is the main culprit in the anomaly in the South Atlantic. In numerical simulations, unusual patches similar to this have appeared just before geomagnetic reversals.

Throughout the history of the planet magnetic poles changed quite often, but the last reversal occurred in the distant past, about 780 thousand years ago. Given the rapid decline in the strength of the magnetic field in the last 160 years, the question arises of what happened before.

The study of archeomagnetism

During archeomagnetic research, geophysicists and archaeologists try to learn about the past of the magnetic field. For example, the clay used to make pottery contains no a large number of magnetic minerals such as magnetite. When the clay was heated during the process of making pottery, its magnetic minerals lost the magnetism they may have had. When cooled, they recorded the direction and intensity of the magnetic field at that time. If the age of the pottery can be determined (using radiocarbon dating, for example), then there is also a chance to reconstruct the archeomagnetic history.

Through the use of this kind of data, scientists have a partial history of archeomagnetism for northern hemisphere. In contrast to this, in southern hemisphere these records are very scarce. In particular, there is virtually no data from South Africa, which, along with South America, could provide a better understanding of the history of the modern anomaly.

Archeomagnetic history of southern Africa

But the ancestors of modern South Africans, metallurgists and farmers who began to migrate to the region about 2000-1500 years ago, accidentally left us some clues. These Iron Age people lived in mud huts and stored grain in fortified mud bins. As the first Iron Age agronomists in southern Africa, they relied on rainfall.

These communities often responded to times of drought with cleansing rituals that entailed the burning of granaries. These somewhat tragic events for ancient people were ultimately a boon for the study of archeomagnetism. As with the firing and cooling of pottery, the clay in the granaries recorded the earth's magnetic field as it cooled. Since these ancient huts and grain bins are sometimes found intact, scientists can use them to get data on the direction and strength of the magnetic field at that time.

Scientists have focused their attention on sampling from the Iron Age sites that dot the valley of the Limpopo River.

Magnetic field flux

Sampling along the length of the Limpopo River provided the first data on the magnetic field of southern Africa between 1000 and 1600 AD. Scientists have found that around 1300, the strength of the magnetic field in this area was declining as rapidly as it is today. Then its intensity increased, albeit at a slower pace.

The appearance of two intervals of rapid field decay - about 700 years ago and the present one - suggests the opposite phenomenon. Perhaps in South Africa did this anomaly appear regularly, and is it older than the data showed? If so, why is it repeated in the same place?

Over the past decade, researchers have accumulated seismic wave analysis data from earthquakes. Since seismic waves travel through the layers of the Earth, the speed at which they travel is an indication of the density of the layer. Scientists now know that a large area of ​​slow seismic waves characterizes the main mantle boundary under southern Africa.

This particular region is most likely tens of millions of years old, and its boundaries are clear. It is interesting to note that the spot of reverse polarity practically coincides with its eastern edge.

Scientists believe that the unusual African mantle changes the flow of iron in the core from below, which, in turn, changes the behavior of the magnetic field at the edge of the seismic region and the reverse polarity patch.

It is assumed that this area grows rapidly and then slowly returns to normal. From time to time, a single spot of reversed polarity can grow large enough to dominate the southern hemisphere's magnetic field.

How does inversion happen?

The traditional idea of ​​inversion is that it can start anywhere in the nucleus. However, the new conceptual model suggests that there may be specific locations at the core-mantle interface that contribute to these reversals of the magnetic field. It is not yet known whether the current magnetic field will begin to decrease in the next few thousand years, or if it will simply continue to weaken over the next two centuries.

But the evidence provided by the ancestors of modern South Africans will no doubt help scientists further study their proposed inversion mechanism. If this idea is correct, the pole reversal could start in Africa.

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The Earth's magnetic field is a natural "shield" of the planet from the cosmic and solar radiation. In fact, if the Earth did not have its own magnetic field, then life, in the form familiar to us, would be impossible on it. The intensity of the Earth's magnetic field is distributed non-uniformly and averages about 50,000 nT (0.5 Oe) on the surface and varies from 20,000 nT to 60,000 nT.

Rice. 1. "Snapshot" of the main magnetic field on the Earth's surface in June 2014 based on data from Swarm satellites . Areas of a strong magnetic field are marked in red, and areas of a weakened one are marked in blue.

However, observations show that Earth's magnetic field is gradually weakening, while the geomagnetic poles are shifting. As stated in the aforementioned report, these processes are influenced, first of all, by certain cosmic factors, although traditional science does not yet know about them and does not take them into account, trying to find answers in the bowels of the Earth to no avail.

Data transmitted by Swarm satellites launched by the European Space Agency (ESA) ), confirm the general trend of the weakening of the magnetic field, and the highest level of decline is observed in the Western Hemisphere of our planet .

Rice. 2. Change in the strength of the Earth's magnetic field over the periodfrom January 2014 to June 2014 according to Swarm. In the figure, lilac color corresponds to an increase, and dark blue - to a decrease in the intensity in the range of ±100 nT.

Analyzing the consequences of many natural disasters, scientists have found that before the start of seismic activity, anomalies of the Earth's magnetic field appear. In particular, the earthquake that occurred on March 11, 2011 in Japan was preceded by the activation of the Pacific lithospheric plate in subduction zones. This event has become a kind of indicator of a new phase of seismic activity associated with the acceleration of the movement of this lithospheric plate. The displacement of the geomagnetic poles located in Eastern Siberia and the Pacific Ocean, due to cosmic factors, led to large-scale changes in secular magnetic variations in the territory of the Japanese archipelago. The result of these phenomena was a series powerful earthquakes, magnitude 9.0.

It is officially believed that over the past 100 years, the Earth's magnetic field has weakened by about 5%. In the region of the so-called South Atlantic Anomaly off the coast of Brazil, the attenuation was even more significant. However, it is worth noting that earlier, however, as now, ground-based measurements are carried out pointwise, moreover, on land, which can no longer reflect the full picture of secular changes in the magnetic field. Holes in the Earth's magnetic field are also not taken into account - a kind of gaps in the magnetosphere through which huge fluxes of solar radiation penetrate. For reasons unknown to conventional science, the number of these holes is constantly growing. But we will talk about them in future posts.

It is known that the weakening of the Earth's magnetic field leads to a polarity reversal, in which the north and south magnetic poles change places, their inversion occurs. Research in the field of paleomagnetism has shown that earlier during polarity reversals, which occurred gradually, the Earth's magnetic field lost its dipole structure. The inversion of the magnetic field was preceded by its weakening, and after it the field strength increased again to the previous values. In the past, these reversals occurred on average about every 250,000 years. But since the last, according to scientists, about 780,000 years have passed. However, official science cannot yet give any explanation for such a long period of stability. In addition, the correctness of the interpretation of paleomagnetic data is periodically criticized in scientific circles. One way or another, but the rapid weakening of the magnetic field today is a sign of the beginning of global processes, both in outer space, as well as in the bowels of the Earth. That is why the cataclysms occurring on the planet are caused more by natural factors than by anthropogenic influence.

Traditional science still finds it difficult to find an answer to the question: what happens to the magnetic field at the moment of inversion? Does it disappear completely or does it weaken to certain critical values? There are many theories and assumptions about this, but none of them seem to be reliable. One of the attempts to simulate the magnetic field at the moment of reversal is shown in Fig. 3:

Rice. 3. Model representation of the main magnetic field of the Earth in its state of the art(left) and in the process of polarity reversal (right). Over time, the Earth's magnetic field from a dipole can turn into a multipole one, and then a stable dipole structure will form again. However, the direction of the field will change to the opposite: the north geomagnetic pole will be in place of the south, and the south will move into the Northern Hemisphere.

The very fact of the presence of significant magnetic anomalies at the time of polarity reversal can lead to global tectonic phenomena on Earth, and also pose a serious danger to all life on the planet due to the rising level of solar radiation.

The development of methods for observing the Earth's magnetic field, as well as for septon field of the Earth is engaged in . These data make it possible to timely respond to their variations and take countermeasures aimed at eliminating or minimizing natural disasters. Preliminary identification of the sources of future elements (earthquakes, volcanic eruptions, tornadoes, hurricanes) makes it possible to launch adaptive mechanisms, which significantly reduces the intensity of seismic and volcanic activity, and there is time to warn the population living in a dangerous area. This direction of advanced scientific research called climate geoengineering and includes the development of its new direction and methods, completely safe for the integrity of the ecosystem and the life of people, based on a fundamentally new understanding of physics - TO PRIMORDIAL ALLATRA PHYSICS. To date, a number of successful steps have been taken in this direction, which have acquired a solid scientific basis and practical confirmation. The initial stage of the practical development of this direction is already demonstrating stable results ... .

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Literature:

Report “On the problems and consequences of global climate change on Earth. Effective Ways to Solve These Problems” by an international group of scientists of ALLATRA International Public Movement, November 26, 2014;

27.07.11 The magnetic layer of the Earth began to shrink at a high speed.
This will lead to an increase radiation background and weakening the protection of all living things. World science is concerned: new satellites are being launched to record the rate of these messages.

General: The earth has a magnetic field, the north pole of which is located at the geographic south pole.

To obtain a magnetic field of the desired direction, around the globe, in a plane perpendicular to the axis of rotation of the Earth, there must be a stable current sheet. Such a layer exists and is called the ionosphere.

The sun, as a result nuclear reactions flowing in it, radiates into the surrounding space great amount charged particles of high energy, the so-called solar wind.

In composition, the solar wind contains mainly protons, electrons, a few helium nuclei, oxygen ions, silicon, sulfur, and iron. Particles that form the solar wind are entrained upper layers atmosphere in the direction of the Earth's rotation. Thus, a directed flow of electrons is formed around the Earth, moving in the direction of the Earth's rotation. As a result of the presence of this current, the Earth's magnetic field is excited.

As a result of the interaction of the ionospheric current and the Earth's magnetic field, a torque acts on the Earth, directed in the direction of the Earth's rotation.
Thus, the Earth with respect to the solar wind behaves similarly to a DC motor with self-excitation. The source of energy (generator) in this case is the Sun.

It should be noted that magnetic flux, caused by the current of the solar wind, penetrates the flow of red-hot lava inside it, which rotates with the Earth.
As a result of the interaction of the current field of the ionosphere and the flow of red-hot lava, an electromotive force is induced in it, under the influence of which a current flows, which also creates a magnetic field. As a result, the Earth's magnetic field is the resulting field from the interaction of the ionospheric current and the lava current.

Since both the magnetic field and the torque acting on the earth depend on the current in the ionosphere, and the latter on the degree of solar activity, with an increase in solar activity, the torque acting on the Earth should increase and the speed of its rotation should increase.

What is happening to the Earth's magnetic field today? I asked the famous nuclear physicist Igor Nikolaevich Ostretsov.

The actual picture of the Earth's magnetic field depends not only on the configuration of the current sheet, but also on magnetic properties earth's crust, as well as on the relative location of magnetic anomalies.

Here we can draw an analogy with a circuit with current in the presence of a ferromagnetic core and without it. It is known that a ferromagnetic core not only changes the configuration of the magnetic field, but also significantly enhances it.

The current sheet of the Earth, to a large extent, determines the course of electrical processes in the atmosphere (thunderstorms, auroras, the fires of "Saint Elmo").
It has been noted that during volcanic eruptions, electrical processes in the atmosphere are significantly activated. This phenomenon can be explained as follows. When a volcano erupts, a column of hot gases (plasma) is ejected. The convective motion of hot gases closes the current sheet of the ionosphere with the Earth's surface. Thus, a leakage current appears, which activates electrical processes during eruptions.

In particular, it is possible that the relationship electromagnetic processes in the Sun-Earth system can provide the possibility of developing powerful power plants using solar energy.

It is known that the geographic poles constantly make complex loop-like movements in the direction of the Earth's daily rotation with a period of 25,776 years.

Typically, these movements occur near the imaginary axis of rotation of the Earth and do not lead to noticeable climate change. But few people noticed that at the end of 1998 the overall component of these movements shifted. Within a month, the pole shifted towards Canada by 50 kilometers. At present, the north pole is "creeping" along the 120th parallel of the western longitude.

It can be assumed that if the current trend in the movement of the poles continues until 2015, then the north pole can move 3-4 thousand kilometers. The end point of the drift is the Great Bear Lakes in Canada. The South Pole, accordingly, will shift from the center of Antarctica to the Indian Ocean.

The shift of the magnetic poles has been recorded since 1885. Over the past 100 years, the magnetic pole in the southern hemisphere has moved almost 900 km and Indian Ocean.

The latest data on the state of the Arctic magnetic pole (moving towards the East Siberian world magnetic anomaly through the Arctic Ocean): showed that from 1973 to 1984. its movement was 120 km, from 1984 to 1994. - more than 150 km. Characteristically, these calculated data were confirmed by specific measurements of the location of the north magnetic pole. As of the beginning of 2002, the drift velocity of the north magnetic pole increased from 10 km/year in the 1970s to 40 km/year in 2001.

In addition, the strength of the earth's magnetic field is decreasing, and very unevenly.

Thus, over the past 22 years, it has decreased by an average of 1.7 percent, and in some regions - for example, in the southern part Atlantic Ocean, - by 10 percent. However, in some places on our planet, the magnetic field strength, contrary to the general trend, even slightly increased.

We emphasize that the acceleration of the movement of the poles (by an average of 3 km/year per decade) makes us think that this movement of the poles should be seen not as a particular phenomenon, but as a reversal of the Earth's magnetic field.

The acceleration could drive the poles up to 200 km per year, so that the reversal would take place much faster than currently thought. And of course it's not safe.

In the history of the Earth, changes in the position of the geographic poles have occurred repeatedly, and this phenomenon is primarily associated with the glaciation of vast areas of land and cardinal changes in the climate of the entire planet.
Writers called another name for this phenomenon "earth somersault".

But echoes in human history received only last disaster, most likely associated with a pole shift that occurred about 12 thousand years ago. All we know is that mammoths are extinct. But everything was much more serious.

The extinction of hundreds of animal species is undeniable.
O Flood, The death of Atlantis, the emergence of the Black Sea are under discussion. But one thing is certain - the echoes of the greatest catastrophe in the memory of mankind have a real basis. And it was caused, most likely, by a pole shift of only 2000 km.

Dear Igor Nikolaevich, please comment on what caused the polarization reversal and is it dangerous for humanity?

Scientists have long wondered why the Earth's magnetic poles change places from time to time. Recent studies of the vortex movements of molten masses inside the Earth allow us to understand how polarization reversal occurs. A magnetic field, much more intense and more complex than the field of the core, within which magnetic oscillations are formed, was found at the boundary between the mantle and the core.

It is important that most of the geomagnetic field is formed only in four vast areas at the boundary between the core and the mantle. Although the geodynamo produces a very strong magnetic field, only 1% of its energy propagates outside the core. The general configuration of the magnetic field measured at the surface is called a dipole, which is oriented along most of the time. earth's axis rotation. As in the field of a linear magnet, the main geomagnetic flux is directed from the center of the Earth in the Southern Hemisphere and towards the center - in the Northern Hemisphere. Space observations have shown that the magnetic flux has an uneven global distribution, the greatest intensity can be traced on the Antarctic coast, under North America and Siberia.

Ulrich R. Christensen of the Max Planck Solar System Research Institute in Katlenburg-Lindau, Germany, believes that these vast tracts of earth have existed for thousands of years and are maintained by an ever-evolving convection within the core.

Could similar phenomena be the cause of the pole reversal? Historical geology testifies that the pole changes occurred in relatively short periods of time - from 4 thousand to 10 thousand years. If the geodynamo ceased its work, then the dipole would have existed for another 100 thousand years. A rapid reversal of polarity gives reason to believe that some unstable position violates the original polarity and causes a new change of poles.

In some cases, the mysterious instability can be explained by some chaotic change in the structure of the magnetic flux, which only accidentally leads to polarization reversal.

However, the frequency of polarity reversal, which has become more and more stable over the past 120 million years, indicates the possibility of external regulation. One of the reasons for it may be a temperature drop in the lower layer of the mantle, and as a result, a change in the nature of the effusions of the core.

Some symptoms of repolarization have been identified in the analysis of maps that were made from satellites.

Long-term changes in the geomagnetic field occur at the boundary of the core and mantle in those places where the direction of the geomagnetic flux is opposite to normal for a given hemisphere. The largest of the so-called sections of the reverse magnetic field stretches from the southern tip of Africa west to South America. In this area, the magnetic flux is directed inward, towards the core, while most of it in the Southern Hemisphere is directed from the center.

Areas where the magnetic field is directed in the opposite direction for a given hemisphere arise when twisted and winding lines of the magnetic field accidentally break through the Earth's core.

Plots of a reverse magnetic field can significantly weaken the magnetic field on the Earth's surface, called a dipole, and indicate the beginning of a change in the earth's poles. They appear when a rising liquid mass pushes horizontal magnetic lines up in the molten outer core. In this sense, it is difficult to predict exactly how the climate on the planet will change. And such changes, of course, can lead to disasters.

The most significant discovery made when comparing the latest measurements was that new regions of the reverse magnetic field continue to form, for example, at the core-mantle boundary under the east coast North America and the Arctic.
Moreover, the previously identified areas have grown and moved slightly towards the poles. At the end of the 80s. 20th century David Gubbins of the University of Leeds in England, studying old maps of the geomagnetic field, noted that the spread, growth and shift towards the poles of reversed magnetic fields explains the decrease in the strength of the dipole in historical time.

When the rotation brings the region of the reverse magnetic field closer to the geographic pole than the region with normal flux, there is a weakening of the dipole, which is most vulnerable near its poles.
In this way, the reverse magnetic field in southern Africa can be explained. With a global onset of a reversal of the poles, sections of the reverse magnetic field can grow throughout the region near the geographic poles.

And here, Kyiv professor, doctor of physical and mathematical sciences, director of the Ukrainian Institute of Human Ecology Mikhail Vasilievich Kurik connects life expectancy with the strength of the Earth's magnetic field.

Fifty years ago, a famous Japanese scientist, Dr. Nakagawa, described new disease, which affects a huge number of people on earth, and called it "human magnetic field deficiency syndrome".

Dr. Nakagawa came to the most serious conclusion, which made it possible to treat a large number of diseases. He described the "magnetic field deficiency syndrome", leading to the formation of dozens of pathological processes. The main manifestations of the syndrome are: general weakness, increased fatigue, reduced performance, poor sleep, headache, pain in the joints and spine, pathology of the cardiovascular system, hyper- and hypotension, digestive disorders, skin changes, prostate problems, gynecological dysfunctions and a number of other processes.

Tell me: are there really problems with weak magnetic fields?

Since the Earth's magnetic field simultaneously protects a person from dangerous solar and cosmic radiation, according to scientists, a decrease in the magnetic field at high altitudes increases the risk of such effects dangerous to the body.

In the experiments, mice were placed in chambers shielded from the Earth's magnetic field. A day later, they began to decompose tissues. The cubs of such mice were born bald and grew sick.

The planet's magnetic field protects us from the high-energy plasma streams erupted by the Sun.

A decrease in the Earth's magnetic field means a weakening of this protection and a corresponding increase in the radiation background. Which, of course, can lead to serious illness.

A team of European researchers compared the current state of the Earth's magnetic field with its turbulent geological past and found that the current signs of a magnetic field disturbance are unlike those that preceded previous pole shifts.

The current situation resembles the events of 49,000 years and 46,000 years ago - when there was some significant weakening in the strength of the magnetic field, but without a sharp shift in the poles. However, scientists still have many questions about what will happen next with the magnetic field.

The magnetic field inherently provides comfortable conditions for life on our planet. It protects the Earth from cosmic radiation and solar storms. In other words, if we did not have a magnetic field, the Earth would probably look like a red wasteland, and life would hardly have evolved so much on our planet.

Moreover, this shielding effect deflects the charged particles of the solar wind and prevents the occurrence of failures on orbiting satellites important for GPS navigation, communications, and meteorology.

Current magnetic north and magnetic south are close to geographic poles. Since direct observations began in the 19th century, scientists have noticed that the strength of the field has been weakening by about 5 percent every 100 years for at least the last two millennia.

Of particular interest is the "South Atlantic Anomaly" - an inexplicably weak part of the field, where charged particles are strongly deflected and can cause serious damage to satellites.

The team decided to study several different periods of the magnetic field. Although the current anomaly in the South Atlantic is strange, the magnetic field of 49,000 and 46,000 years was similar without any extreme events. In all cases, the field after the anomalies was stabilized by strong poles over several thousand years.

So, it is unlikely that we will see a polar reversal. "The overall conclusion is consistent with other recent studies that show that the current decline in field strength is not caused by its accelerated displacement," says Mound. "The field strength fluctuates quite a lot over time, and there is nothing unusual about the ratio of current strength or rate of change."

Phil Livermore, a geophysicist at the University of Leeds, is a bit optimistic. He points out that there is no new evidence that the current weakening will stop, especially since we still do not know what causes it.

While the history of the magnetic field provides a useful insight into how it works and behaves, none of this research actually helps us predict the future. They only indicate a large number of options.

Should we be worried? Kurgan doesn't think, "The rate of change is slow enough for us to soften the blows." But he cautions that we don't know enough about exactly what those impacts will be.

The Earth's magnetic field is similar to the magnetic field of a giant permanent magnet tilted at an angle of 11 degrees to its axis of rotation. But there is a nuance here, the essence of which is that the Curie temperature for iron is only 770°C, while the temperature of the Earth's iron core is much higher, and only on its surface is about 6000°C. At this temperature, our magnet would not be able to maintain its magnetization. This means that since the core of our planet is not magnetic, terrestrial magnetism has a different nature. So where does the Earth's magnetic field come from?

As you know, magnetic fields surround electric currents, therefore, there is every reason to assume that the currents circulating in the molten metal core are the source of the earth's magnetic field. The shape of the Earth's magnetic field is indeed similar to the magnetic field of a coil with current.

The magnitude of the magnetic field measured on the Earth's surface is about half a Gauss, while lines of force as if they leave the planet from the side of the south pole and enter its north pole. At the same time, over the entire surface of the planet, the magnetic induction varies from 0.3 to 0.6 Gauss.

In practice, the presence of a magnetic field near the Earth is explained by the dynamo effect arising from the current circulating in its core, but this magnetic field is not always constant in direction. Rock samples taken in the same places, but having different ages, differ in the direction of magnetization. Geologists report that over the past 71 million years, the Earth's magnetic field has reversed 171 times!

Although the dynamo effect has not been studied in detail, the rotation of the Earth certainly plays an important role in the generation of currents, which are supposed to be the source of the Earth's magnetic field.

The Mariner 2 probe, which explored Venus, found that Venus does not have such a magnetic field, although its core, like the Earth's core, contains enough iron.

The answer is that the period of rotation of Venus around its axis is 243 days on Earth, that is, the dynamo generator of Venus rotates 243 times slower, and this is not enough to produce a real dynamo effect.

Interacting with particles of the solar wind, the Earth's magnetic field creates the conditions for the emergence near the poles of the so-called auroras.

The north side of the compass needle is the magnetic north pole, which is always oriented towards the geographic north pole, which is practically magnetic south pole. After all, as you know, opposite magnetic poles attract each other.

However, the simple question is, "how does the Earth get its magnetic field?" - still does not have a clear answer. It is clear that the generation of the magnetic field is associated with the rotation of the planet around its axis, because Venus with a similar composition of the core, but rotating 243 times slower, does not have a measurable magnetic field.

It seems plausible that from the rotation of the liquid of the metallic core, which constitutes the main part of this core, a picture of a rotating conductor arises, creating a dynamo effect and working like an electric generator.

Convection in the liquid of the outer part of the core leads to its circulation with respect to the Earth. This means that the electrically conductive material moves relative to the magnetic field. If it turns out to be charged due to friction between the layers in the core, then the effect of a coil with current is quite possible. Such a current is quite able to maintain the Earth's magnetic field. large-scale computer models confirm the reality of this theory.

In the 50s, as part of the strategy " cold war”, U.S. Navy vessels towed sensitive magnetometers across the ocean floor as they looked for a way to detect Soviet submarines. In the course of observations, it turned out that the Earth's magnetic field fluctuates within 10% with respect to the magnetism of the rocks of the seabed itself, which had the opposite direction of magnetization. The result was a pattern of reversals that occurred up to 4 million years ago, this was calculated by the potassium-argon archaeological method.

Andrey Povny