At the junctions of lithospheric plates, large faults in the earth's crust often form. Sometimes faults of smaller area and depth may appear in the earth's crust, confirming the relative movement of the earth's masses. During a geological fault, the continuous occurrence of rocks is disrupted, both without displacement (crack) and with displacement of rocks along the surface of the rupture.

In areas with active faults, earthquakes are often observed as a result of the release of energy as plates rapidly slide along a fault line. Typically, faults are not a single rupture or crack. An area of ​​similar tectonic deformation in the same plane is called a fault zone.

In the mining industry, terms such as hanging wall and footwall are used to refer to the two sides of a non-vertical fault, located above and below the fault line, respectively.

Geological faults

All geological faults are divided into three groups according to the direction of movement. If a fault occurs in a vertical plane, it is called a fault with a dip offset, in a horizontal plane it is called a strike-slip fault, and in these two planes it is called a normal-slip fault.

Faults of the earth's crust with displacement along the dip, in turn, combine three types:- reverse faults; - discharges; - thrusts.

During reverse faults, compression of the earth's crust occurs, while the hanging wall moves upward in relation to the base, and the angle of inclination of the crack is more than 45°. The appearance of faults is observed when the earth's crust stretches. In this case, the hanging side of the earth's crust block descends relative to the base. The part of the earth's crust that has sunk below other fault areas is called a graben. Elevated fault areas are horsts. A thrust fault is a fault in the earth’s crust with a direction of movement of layers similar to a reverse fault, but unlike it, with a crack inclination angle of less than 45°. During thrusts, slopes, folds and rifts are formed.

Shifts are characterized by the vertical location of the fault surface, with the base moving to the right or left. Accordingly, right-sided and left-sided shifts are distinguished. There is a type of shift known as a transform fault, which occurs perpendicular to the mid-ocean ridge and divides it into sections up to 400 km wide.

The thickness of faults is usually measured by the amount of deformed rock and determines the layer of the earth's crust where the fault occurred. They also evaluate rock types and determine the presence of mineralization fluids. With the long-term existence of a large fault - displacement along the dip - rocks from different levels of the earth's crust are layered on top of each other.

The main types of rocks at faults in the earth's crust include mylonite, cataclasite, tectonic breccia, pseudotachylite, and fault mud.

Typically, faults are geochemical barriers that hide solid minerals. Often such barriers are insurmountable for solutions of salts, gas and oil, due to the overlay of rocks. These are due to their capture and formation of deposits.

Deep faults are identified and mapped using satellite images, geophysical research techniques (seismic sounding of the earth's crust, gravimetric survey, magnetic survey), geochemical methods (helium and radon survey).

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In the scientific literature, in publications on the Internet, in blogs and forums, the topic of tectonic faults is increasingly being raised and discussed. True, in the records they most often appear under the name of geopathogenic zones, apparently because this phrase is more often heard and has a pronounced mystical connotation. Meanwhile, most readers know almost nothing about such a phenomenon as a tectonic fault, because its roots lie not in mysticism and esotericism, but in a generally recognized, but not the most popular science today - geology.

A tectonic fault is a zone of disruption of the continuity of the earth's crust, a deformation seam that divides a rock mass into two blocks. Tectonic faults are present in any mountain range in any territory and have been studied by geologists for a long time. It is precisely tectonic faults that are most often associated with deposits of minerals - metal ores, hydrocarbons, groundwater, etc., which makes them a very useful object for research.

Until recently, in geology it was believed that the earth's crust, with the exception of areas of active volcanism and seismic phenomena (dangerous in terms of earthquakes), is in a state of rest, i.e. motionless. However, at the present stage, with the commissioning of new measuring equipment, it has become obvious that the earth's crust is constantly in motion. Roughly speaking, the earth moves right under our feet. These movements have insignificant amplitude and are not noticeable to the eye, however, they can have a significant impact on both rock masses and engineering structures.

Why is the earth's crust mobile? In accordance with Newton's first law, movement occurs under the influence of force. Forces are constantly acting in the earth's crust (one of them is gravity), as a result of which the geological environment is always in a stressed state. Since rocks are always overstressed, they begin to deform and collapse. Most often this is expressed in the formation of tectonic sutures (ruptures) or displacement of rock blocks along previously formed active faults.

Modern displacements along active faults can lead to deformation of the earth's surface and have a mechanical impact on engineering objects. There are known cases when, in zones of active faults, destruction of buildings and structures occurred, constant breaks in water-carrying communications, and the formation of cracks in walls and foundations. Similar emergency buildings and structures exist in almost every city. But cases of deformation of buildings, most often, are not given wide publicity.

The topic of the negative impact of tectonic faults (geopathogenic zones) on human health is often discussed. To date, a number of scientific studies on this topic are known. As a rule, the authors note that tectonic faults do have an impact on living organisms, and this impact may be ambiguous for different species of plants and animals. Basically, among researchers there is an opinion that the impact of tectonic faults on humans is predominantly negative. Some people react quite sharply to tectonic zones, within which their well-being sharply deteriorates. Most people tolerate their stay in fault zones quite calmly, but some deterioration in their condition is noted. A small percentage of people are virtually unaffected by tectonic zones.

It is quite difficult to explain the principles of the negative impact of tectonic disturbance zones on human health. The processes occurring in zones of tectonic disturbances are complex and diverse. An active fault is a zone of concentration of tectonic stress and a zone of increased deformation of the rock mass. Many geologists and geomechanics believe that an overstressed fault zone generates an electromagnetic field. Just like, for example, a mechanical effect on a quartz crystal in a piezoelectric lighter generates a current discharge. In addition, due to increased fracturing, the tectonic fault, in most cases, is an aquifer zone. It is quite obvious that the movement of groundwater with salts dissolved in them (conductor) through rock strata (which differ in their electrical properties) can and does form electric fields and anomalies. That is why anomalies of various natural physical fields are often observed in tectonic fault zones. These anomalies are widely used to search and identify zones of tectonic disturbances in modern geophysics. Most likely, these anomalies also serve as the main source of impact on living organisms, incl. per person.

To date, the problem of studying the influence of tectonic faults on engineering objects and on human health is studied only on the initiative of independent researchers. There are no targeted official programs in this direction. The presence of active tectonic faults is not taken into account when selecting sites for the construction of residential buildings. The issues of searching and identifying zones of displacement of the earth's surface are dealt with only in very rare cases during the construction of objects of a high level of responsibility. In general, it is obvious that among geologists, designers and builders there is a need for a targeted study of anomalous tectonic zones and mandatory consideration of the geodynamic activity of the geological environment in the process of its development.

Geological fault, or gap— violation of the continuity of rocks, without displacement (crack) or with displacement of rocks along the surface of the rupture. Faults prove the relative movement of earth masses. Large faults in the earth's crust are the result of shifting tectonic plates at their junctions. Active fault zones often experience earthquakes as a result of the release of energy during rapid sliding along a fault line. Since most often faults do not consist of a single crack or rupture, but of a structural zone of similar tectonic deformations that are associated with the fault plane, such zones are called fault zones.

The two sides of a non-vertical fault are called hanging side And sole(or recumbent side) - by definition, the first occurs above and the second below the fault line. This terminology comes from the mining industry.

Types of faults

Geological faults are divided into three main groups depending on the direction of movement. A fault in which the main direction of movement occurs in the vertical plane is called fault with dip displacement; if in the horizontal plane, then shift. If the displacement occurs in both planes, then such a displacement is called fault-shift. In any case, the name applies to the direction of movement of the fault, and not to the present orientation, which may have been changed by local or regional folds or tilts.

San Andreas Fault California, USA

A fracture in a metamorphic layer near Adelaide, Australia

Fault with dip offset

Faults with dip displacement are divided into discharges, reverse faults And thrusts. Faults occur when the earth's crust stretches, when one block of the earth's crust (the hanging wall) sinks relative to another (the footwall). A section of the earth's crust that is lowered relative to the surrounding fault areas and located between them is called graben. If the section, on the contrary, is raised, then such a section is called handful. Faults of regional significance with a small angle are called breakdown, or peeling. Reverse faults occur in the opposite direction - in them the hanging wall moves upward relative to the base, while the angle of inclination of the crack exceeds 45°. During reverse faults, the earth's crust contracts. Another type of fault with dip displacement is thrust, in it the movement occurs similar to a reverse fault, but the angle of inclination of the crack does not exceed 45°. Thrusts usually form slopes, rifts and folds. As a result, tectonic nappes and clips. A fault plane is the plane along which the rupture occurs.

Shifts

During shear, the fault surface is vertical and the base moves to the left or right. In left-sided shifts, the sole moves to the left side, in right-sided shifts - to the right. A separate type of shift is transform fault, which runs perpendicular to the mid-ocean ridges and breaks them into segments averaging 400 km wide.

Fault rocks

All faults have a measurable thickness, which is calculated by the size of the deformed rocks, which determine the layer of the earth's crust where the rupture occurred, the type of rocks that underwent deformation and the presence of mineralization fluids in nature. A fault passing through different layers of the lithosphere will have different types of rocks along the fault line. Long-term displacement along the dip leads to the overlapping of rocks with characteristics of different levels of the earth's crust. This is especially noticeable in cases of failures or large thrust faults.

The main types of rocks at faults are the following:

• Cataclasite is a rock whose texture is due to the structureless, fine-grained rock material.
• Mylonite is a shale metamorphic rock formed by the movement of rock masses along the surfaces of tectonic faults, by crushing, grinding and squeezing the minerals of the original rocks.
• Tectonic breccia is a rock consisting of acute-angled, unrounded rock fragments and cement connecting them. Formed as a result of crushing and mechanical abrasion of rocks in fault zones.
• Fault mud is a loose, clay-rich soft rock, in addition to ultrafine-grained catalytic material, which may have a planar pattern and contain< 30 % видимых фрагментов.
• Pseudotachylyte is an ultrafine-grained, glassy rock, usually black in color.

Indication of deep faults

The location of deep faults can be determined on the Earth's surface using helium photography. Helium, as a product of the decay of radioactive elements that saturate the upper layer of the earth's crust, seeps through cracks, rises into the atmosphere, and then into outer space. Such cracks, and especially the places where they intersect, have high concentrations of helium. This phenomenon was first established by the Russian geophysicist I. N. Yanitsky during the search for uranium ores, recognized as a scientific discovery and entered into the State Register of Discoveries of the USSR under No. 68 with priority from 1968 in the following formulation: “A previously unknown pattern has been experimentally established, namely that the distribution of anomalous (increased) concentrations of free mobile helium depends on deep, including ore-bearing, faults in the earth’s crust.”

Plate tectonics

Material from Wikipedia - the free encyclopedia

Map of lithospheric plates

Plate tectonics- modern geological theory about the movement of the lithosphere. She argues that the earth's crust consists of relatively integral blocks - plates that are in constant motion relative to each other. Moreover, in expansion zones (mid-ocean ridges and continental rifts) as a result of spreading (eng. seafloor spreading- spreading of the seafloor) new oceanic crust is formed, and the old is absorbed in subduction zones. The theory explains earthquakes, volcanic activity and mountain building, much of which occurs at plate boundaries.

The idea of ​​the movement of crustal blocks was first proposed in the theory of continental drift, proposed by Alfred Wegener in the 1920s. This theory was initially rejected. The revival of the idea of ​​​​movements in the solid shell of the Earth (“mobilism”) occurred in the 1960s, when, as a result of studies of the relief and geology of the ocean floor, data were obtained indicating the processes of expansion (spreading) of the oceanic crust and the subduction of some parts of the crust under others ( subduction). Combining these ideas with the old theory of continental drift gave rise to the modern theory of plate tectonics, which soon became a generally accepted concept in the earth sciences.

In the theory of plate tectonics, a key position is occupied by the concept of geodynamic setting - a characteristic geological structure with a certain ratio of plates. In the same geodynamic setting, the same type of tectonic, magmatic, seismic and geochemical processes occur.

History of the theory

For more information on this topic see: History of plate tectonics theory.

The basis of theoretical geology at the beginning of the 20th century was the contraction hypothesis. The earth cools like a baked apple, and wrinkles appear on it in the form of mountain ranges. These ideas were developed by the theory of geosynclines, created on the basis of the study of folded structures. This theory was formulated by James Dana, who added the principle of isostasy to the contraction hypothesis. According to this concept, the Earth consists of granites (continents) and basalts (oceans). When the Earth contracts, tangential forces arise in the ocean basins, which press on the continents. The latter rise into mountain ranges and then collapse. The material that results from destruction is deposited in the depressions.

The German meteorologist Alfred Wegener opposed this scheme. On January 6, 1912, he spoke at a meeting of the German Geological Society with a report on continental drift. The starting point for the creation of the theory was the coincidence of the outlines of the western coast of Africa and the eastern coast of South America. If these continents are shifted, then they coincide, as if they were formed as a result of the split of one proto-continent.

Wegener was not satisfied with the coincidence of the outlines of the coasts (which had been repeatedly noticed before him), but began to intensively search for evidence of the theory. To do this, he studied the geology of the coasts of both continents and found many similar geological complexes that coincided when combined, just like the coastline. Another direction to prove the theory was paleoclimatic reconstructions, paleontological and biogeographical arguments. Many animals and plants have limited ranges on both sides of the Atlantic Ocean. They are very similar, but separated by many kilometers of water, and it is difficult to imagine that they crossed the ocean.

In addition, Wegener began to look for geophysical and geodetic evidence. However, at that time the level of these sciences was clearly not sufficient to record the modern movement of the continents. In 1930, Wegener died during an expedition in Greenland, but before his death he already knew that the scientific community did not accept his theory.

Initially continental drift theory was received favorably by the scientific community, but in 1922 it was subjected to severe criticism from several well-known specialists. The main argument against the theory was the question of the force that moves the plates. Wegener believed that the continents moved along the basalts of the ocean floor, but this required enormous force, and no one could name the source of this force. The Coriolis force, tidal phenomena and some others were proposed as a source of plate movement, but the simplest calculations showed that all of them were absolutely insufficient to move huge continental blocks.

Critics of Wegener's theory focused on the question of the force moving the continents, and ignored all the many facts that certainly confirmed the theory. Essentially, they found a single issue on which the new concept was powerless, and without constructive criticism they rejected the main evidence. After the death of Alfred Wegener, the theory of continental drift was rejected, receiving the status of a marginal science, and the vast majority of research continued to be carried out within the framework of the theory of geosynclines. True, she also had to look for explanations of the history of the settlement of animals on the continents. For this purpose, land bridges were invented that connected the continents, but plunged into the depths of the sea. This was another birth of the legend of Atlantis. It is worth noting that some scientists did not recognize the verdict of world authorities and continued to search for evidence of continental movement. Tak du Toit ( Alexander du Toit) explained the formation of the Himalayan mountains by the collision of Hindustan and the Eurasian plate.

The sluggish struggle between the fixists, as supporters of the absence of significant horizontal movements were called, and the mobilists, who argued that the continents do move, flared up with renewed vigor in the 1960s, when, as a result of studying the ocean floor, clues were found to understanding the “machine” called Earth.

By the early 1960s, a relief map of the ocean floor was compiled, which showed that mid-ocean ridges are located in the center of the oceans, which rise 1.5-2 km above the abyssal plains covered with sediment. These data allowed R. Dietz and Harry Hess to put forward the spreading hypothesis in 1962-1963. According to this hypothesis, convection occurs in the mantle at a speed of about 1 cm/year. The ascending branches of convection cells carry out mantle material under the mid-ocean ridges, which renews the ocean floor in the axial part of the ridge every 300-400 years. Continents do not float on the oceanic crust, but move along the mantle, being passively “soldered” into lithospheric plates. According to the concept of spreading, ocean basins have a variable and unstable structure, while continents are stable.

Age of the ocean floor (red color corresponds to young crust)

In 1963, the spreading hypothesis received strong support in connection with the discovery of striped magnetic anomalies on the ocean floor. They were interpreted as a record of reversals of the Earth's magnetic field, recorded in the magnetization of basalts of the ocean floor. After this, plate tectonics began its triumphant march in the earth sciences. More and more scientists realized that, rather than waste time defending the concept of fixism, it was better to look at the planet from the point of view of a new theory and, finally, begin to give real explanations for the most complex earthly processes.

Plate tectonics has now been confirmed by direct measurements of plate velocity using the interferometry radiation from distant quasars and measurements using GPS satellite navigation systems. The results of many years of research have fully confirmed the basic principles of the theory of plate tectonics.

Current state of plate tectonics

Over the past decades, plate tectonics has significantly changed its basic principles. Nowadays they can be formulated as follows:

• The upper part of the solid Earth is divided into a brittle lithosphere and a plastic asthenosphere. Convection in the asthenosphere is the main cause of plate movement.

• The modern lithosphere is divided into 8 large plates, dozens of medium plates and many small ones. Small slabs are located in belts between large slabs. Seismic, tectonic, and magmatic activity is concentrated at plate boundaries.

• To a first approximation, lithospheric plates are described as rigid bodies, and their motion obeys Euler's rotation theorem.

• There are three main types of relative plate movements

1. divergence (divergence), expressed by rifting and spreading;
2. convergence (convergence) expressed by subduction and collision;
3. shear movements along transform geological faults.

• Spreading in the oceans is compensated by subduction and collision along their periphery, and the radius and volume of the Earth are constant up to the thermal compression of the planet (in any case, the average temperature of the Earth's interior slowly decreases over billions of years).

• The movement of lithospheric plates is caused by their entrainment by convective currents in the asthenosphere.

There are two fundamentally different types of the earth's crust - continental crust (more ancient) and oceanic crust (no older than 200 million years). Some lithospheric plates are composed exclusively of oceanic crust (an example is the largest Pacific plate), others consist of a block of continental crust welded into the oceanic crust.

More than 90% of the Earth's surface in the modern era is covered by 8 largest lithospheric plates:

• Australian plate
• Antarctic plate
• African plate
• Eurasian plate
• Hindustan plate
• Pacific Plate
• North American Plate
• South American Plate

Medium-sized plates include the Arabian Peninsula, as well as the Cocos and Juan de Fuca plates, remnants of the enormous Faralon plate that formed much of the Pacific Ocean floor but has now disappeared in the subduction zone beneath the Americas.

The force that moves the plates

Now there is no longer any doubt that the horizontal movement of plates occurs due to mantle thermogravitational currents - convection. The source of energy for these currents is the difference in temperature between the central regions of the Earth, which have a very high temperature (estimated core temperature is about 5000 °C) and the temperature on its surface. Rocks heated in the central zones of the Earth expand (see. thermal expansion), their density decreases, and they float up, giving way to descending colder and therefore heavier masses, which have already given up some of the heat to the earth’s crust. This process of heat transfer (a consequence of the floating of light-hot masses and the sinking of heavy-colder masses) occurs continuously, resulting in convective flows. These flows - currents close on themselves and form stable convective cells, consistent in the directions of flows with neighboring cells. At the same time, in the upper part of the cell, the flow of matter occurs almost in a horizontal plane, and it is this part of the flow that drags the plates in the horizontal direction with enormous force due to the enormous viscosity of the mantle matter. If the mantle were completely liquid - the viscosity of the plastic mantle under the crust would be low (say, like water or something like that), then transverse seismic waves could not pass through a layer of such a substance with low viscosity. And the earth's crust would be carried away by the flow of such matter with a relatively small force. But, due to the high pressure, at relatively low temperatures prevailing on the surface of Mohorovicic and below, the viscosity of the mantle substance here is very high (so on the scale of years, the substance of the Earth’s mantle is liquid (fluid), and on the scale of seconds it is solid).

The driving force for the flow of viscous mantle matter directly below the crust is the difference in heights of the free surface of the mantle between the region of rise and the region of descent of the convection flow. This height difference, one might say, the magnitude of the deviation from isostasy, is formed due to the different densities of a slightly hotter (in the ascending part) and a slightly colder substance, since the weight of the hotter and colder columns in equilibrium is the same (at different densities!). In fact, the position of the free surface cannot be measured, it can only be calculated (the height of the Mohorovicic surface + the height of the column of mantle material, equivalent in weight to the layer of lighter crust above the Mohorovicic surface).

The same driving force (altitude difference) determines the degree of elastic horizontal compression of the crust by the force of viscous friction of the flow against the earth's crust. The magnitude of this compression is small in the region of the ascent of the mantle flow and increases as it approaches the place of descent of the flow (due to the transfer of compressive stress through the stationary hard crust in the direction from the place of ascent to the place of descent of the flow). Above the descending flow, the compression force in the crust is so great that from time to time the strength of the crust is exceeded (in the region of lowest strength and highest stress), and inelastic (plastic, brittle) deformation of the crust occurs—an earthquake. At the same time, entire mountain ranges, for example, the Himalayas, are squeezed out from the place where the crust is deformed (in several stages).

During plastic (brittle) deformation, the stress in it—the compressive force at the source of the earthquake and its surroundings—reduces very quickly (at the rate of crustal displacement during an earthquake). But immediately after the end of the inelastic deformation, the very slow increase in stress (elastic deformation), interrupted by the earthquake, continues due to the very slow movement of the viscous mantle flow, beginning the cycle of preparation for the next earthquake.

Thus, the movement of plates is a consequence of the transfer of heat from the central zones of the Earth by very viscous magma. In this case, part of the thermal energy is converted into mechanical work to overcome frictional forces, and part, having passed through the earth’s crust, is radiated into the surrounding space. So our planet is, in a sense, a heat engine.

There are several hypotheses regarding the cause of the high temperature of the Earth's interior. At the beginning of the 20th century, the hypothesis of the radioactive nature of this energy was popular. It seemed to be confirmed by estimates of the composition of the upper crust, which showed very significant concentrations of uranium, potassium and other radioactive elements, but subsequently it turned out that the content of radioactive elements in the rocks of the earth’s crust is completely insufficient to ensure the observed flow of deep heat. And the content of radioactive elements in the subcrustal material (close in composition to the basalts of the ocean floor) can be said to be negligible. However, this does not exclude a fairly high content of heavy radioactive elements that generate heat in the central zones of the planet.

Another model explains the heating by chemical differentiation of the Earth. The planet was originally a mixture of silicate and metallic substances. But simultaneously with the formation of the planet, its differentiation into separate shells began. The denser metal part rushed to the center of the planet, and silicates concentrated in the upper shells. At the same time, the potential energy of the system decreased and was converted into thermal energy.

Other researchers believe that the heating of the planet occurred as a result of accretion during meteorite impacts on the surface of the nascent celestial body. This explanation is doubtful - during accretion, heat was released almost on the surface, from where it easily escaped into space, and not into the central regions of the Earth.

Secondary forces

The force of viscous friction arising as a result of thermal convection plays a decisive role in the movements of plates, but in addition to it, other, smaller, but also important forces act on the plates. These are Archimedes' forces, ensuring the floating of a lighter crust on the surface of a heavier mantle. Tidal forces caused by the gravitational influence of the Moon and the Sun (the difference in their gravitational influence on points of the Earth at different distances from them). And also the forces arising as a result of changes in atmospheric pressure on various parts of the earth's surface - the forces of atmospheric pressure quite often change by 3%, which is equivalent to a continuous layer of water 0.3 m thick (or granite at least 10 cm thick). Moreover, this change can occur in a zone hundreds of kilometers wide, while the change in tidal forces occurs more smoothly - over distances of thousands of kilometers.

Divergent boundaries or plate boundaries

These are boundaries between plates moving in opposite directions. In the Earth's topography, these boundaries are expressed as rifts, where tensile deformations predominate, the thickness of the crust is reduced, the heat flow is maximum, and active volcanism occurs. If such a boundary forms on a continent, then a continental rift is formed, which can later turn into an oceanic basin with an oceanic rift in the center. In oceanic rifts, new oceanic crust is formed as a result of spreading.

Ocean rifts

Scheme of the structure of the mid-ocean ridge

For more on this topic, see: Mid-Ocean Ridge.

On the oceanic crust, rifts are confined to the central parts of mid-ocean ridges. New oceanic crust is formed in them. Their total length is more than 60 thousand kilometers. They are home to many hydrothermal springs, which carry a significant portion of deep heat and dissolved elements into the ocean. High temperature sources are called black smokers, significant reserves are associated with them non-ferrous metals.

Continental rifts

The splitting of the continent into parts begins with the formation of a rift. The crust thins and moves apart, and magmatism begins. An extended linear depression with a depth of about hundreds of meters is formed, which is limited by a series of faults. After this, two scenarios are possible: either the expansion of the rift stops and it fills sedimentary rocks, turning into an aulacogen, or the continents continue to move apart and between them, already in typically oceanic rifts, oceanic crust begins to form.

Convergent boundaries

For more on this topic, see: Subduction Zone.

Convergent boundaries are boundaries where plates collide. Three options are possible:

1. Continental plate with oceanic plate. Oceanic crust is denser than continental crust and sinks beneath the continent in a subduction zone.
2. Oceanic plate with oceanic plate. In this case, one of the plates creeps under the other and a subduction zone is also formed, above which an island arc is formed.
3. Continental plate with continental one. A collision occurs and a powerful folded area appears. A classic example is the Himalayas.

In rare cases, oceanic crust is pushed onto the continental crust - obduction. Thanks to this process, ophiolites of Cyprus, New Caledonia, Oman and others arose.

Subduction zones absorb oceanic crust, thereby compensating for its appearance at mid-ocean ridges. Extremely complex processes and interactions between the crust and mantle take place in them. Thus, the oceanic crust can pull blocks of continental crust into the mantle, which, due to their low density, are exhumed back into the crust. This is how metamorphic complexes of ultra-high pressures arise, one of the most popular objects of modern geological research.

Most modern subduction zones are located along the periphery of the Pacific Ocean, forming the Pacific Ring of Fire. The processes occurring in the plate convection zone are rightfully considered to be among the most complex in geology. It mixes blocks of different origins, forming a new continental crust.

Active continental margins

Active continental margin

For more on this topic, see: Active Continental Margin.

An active continental margin occurs where oceanic crust subducts beneath a continent. The standard of this geodynamic situation is considered to be the western coast of South America; it is often called Andean type of continental margin. The active continental margin is characterized by numerous volcanoes and generally powerful magmatism. Melts have three components: the oceanic crust, the mantle above it, and the lower continental crust.

Beneath the active continental margin, there is active mechanical interaction between the oceanic and continental plates. Depending on the speed, age and thickness of the oceanic crust, several equilibrium scenarios are possible. If the plate moves slowly and has a relatively low thickness, then the continent scrapes off the sedimentary cover from it. Sedimentary rocks are crushed into intense folds, metamorphosed and become part of the continental crust. The resulting structure is called accretionary wedge. If the speed of the subducting plate is high and the sedimentary cover is thin, then the oceanic crust erases the bottom of the continent and draws it into the mantle.

Island arcs

Island arc For more information on this topic, see: Island arc.

Island arcs are chains of volcanic islands above a subduction zone, occurring where an oceanic plate subducts beneath an oceanic plate. Typical modern island arcs include the Aleutian, Kuril, Mariana Islands, and many other archipelagos. Japanese islands also often called an island arc, but their foundation is very ancient and in fact they were formed by several complexes of island arcs at different times, so the Japanese islands are a microcontinent.

Island arcs are formed when two oceanic plates collide. In this case, one of the plates ends up at the bottom and is absorbed into the mantle. Island arc volcanoes form on the upper plate. The curved side of the island arc is directed towards the absorbed plate. On this side there is a deep-sea trench and a forearc trough.

Behind the island arc there is a back-arc basin (typical examples: the Sea of ​​Okhotsk, the South China Sea, etc.) in which spreading can also occur.

Continental collision

Collision of continents

For more information on this topic, see: Continental collision.

The collision of continental plates leads to the collapse of the crust and the formation of mountain ranges. An example of a collision is Alpine-Himalayan mountain belt, formed as a result of the closure of the Tethys Ocean and the collision with the Eurasian plate of Hindustan and Africa. As a result, the thickness of the crust increases significantly; under the Himalayas it reaches 70 km. This is an unstable structure; it is intensively destroyed by surface and tectonic erosion. In the crust with a sharply increased thickness, granites are smelted from metamorphosed sedimentary and igneous rocks. This is how the largest batholiths were formed, for example, Angara-Vitimsky and Zerendinsky.

Transform boundaries

Where plates move in parallel courses, but at different speeds, transform faults arise - enormous shear faults, widespread in the oceans and rare on continents.

Transform faults

For more information on this topic, see: Transform fault.

In the oceans, transform faults run perpendicular to mid-ocean ridges (MORs) and break them into segments averaging 400 km wide. Between the ridge segments there is an active part of the transform fault. Earthquakes and mountain building constantly occur in this area; numerous feathering structures are formed around the fault - thrusts, folds and grabens. As a result, mantle rocks are often exposed in the fault zone.

On both sides of the MOR segments there are inactive parts of transform faults. There are no active movements in them, but they are clearly expressed in the topography of the ocean floor by linear uplifts with a central depression.

Transform faults form a regular network and, obviously, do not arise by chance, but due to objective physical reasons. A combination of numerical modeling data, thermophysical experiments and geophysical observations made it possible to find out that mantle convection has a three-dimensional structure. In addition to the main flow from the MOR, longitudinal currents arise in the convective cell due to the cooling of the upper part of the flow. This cooled substance rushes down along the main direction of the mantle flow. Transform faults are located in the zones of this secondary descending flow. This model agrees well with the data on heat flow: a decrease in heat flow is observed above transform faults.

Continental shifts

For more information on this topic, see: Shift.

Strike-slip plate boundaries on continents are relatively rare. Perhaps the only currently active example of a boundary of this type is the San Andreas fault, which separates the North American plate from the Pacific plate. The 800-mile San Andreas Fault is one of the most seismically active areas on the planet: plates move relative to each other by 0.6 cm per year, earthquakes with a magnitude of more than 6 units occur on average once every 22 years. The city of San Francisco and much of the San Francisco Bay area are built in close proximity to this fault.

Within-plate processes

The first formulations of plate tectonics argued that volcanism and seismic phenomena are concentrated along plate boundaries, but it soon became clear that specific tectonic and magmatic processes also occur within plates, which were also interpreted within the framework of this theory. Among intraplate processes, a special place was occupied by the phenomena of long-term basaltic magmatism in some areas, the so-called hot spots.

Hot Spots

There are numerous volcanic islands at the bottom of the oceans. Some of them are located in chains with successively changing ages. A classic example of such an underwater ridge is the Hawaiian Underwater Ridge. It rises above the surface of the ocean in the form of the Hawaiian Islands, from which a chain of seamounts with continuously increasing age extends to the northwest, some of which, for example, Midway Atoll, come to the surface. At a distance of about 3000 km from Hawaii, the chain turns slightly north and is called Imperial Ridge. He breaks off at deep sea trench in front of the Aleutian island arc.

To explain this amazing structure, it was suggested that there is a hot spot under the Hawaiian Islands - a place where a hot mantle flow rises to the surface, which melts the oceanic crust moving above it. There are many such points now installed on Earth. The mantle flow that causes them was called a plume. In some cases, the origin of the plume matter is assumed to be extremely deep, down to the core-mantle boundary.

Traps and oceanic plateaus

In addition to long-term hot spots, enormous outpourings of melts sometimes occur inside the plates, which form traps on the continents and oceanic plateaus in the oceans. The peculiarity of this type of magmatism is that it occurs in a short geological sense of time- about several million years, but covers huge areas (tens of thousands of km²); at the same time, a colossal volume of basalts is poured out, comparable to their amount crystallizing in the mid-ocean ridges.

Siberian traps are known for East Siberian platform, traps of the Deccan plateau on the Hindustan continent and many others. Hot mantle flows are also considered to be the cause of the formation of traps, but unlike hot spots, they act for a short time, and the difference between them is not entirely clear.

From point of view kinematic approach, the movements of the plates can be described by the geometric laws of movement of figures on a sphere. The Earth is seen as a mosaic of plates of different sizes moving relative to each other and the planet itself. Paleomagnetic data allows us to reconstruct the position of the magnetic pole relative to each plate at different points in time. Generalization of data for different plates led to the reconstruction of the entire sequence of relative movements of the plates. Combining this data with information obtained from fixed hot spots made it possible to determine the absolute movements of the plates and the history of the movement of the Earth's magnetic poles.

Thermophysical approach considers the Earth as a heat engine in which thermal energy is partially converted into mechanical energy. Within the framework of this approach, the movement of matter in the inner layers of the Earth is modeled as a flow of a viscous fluid described by the Navier-Stokes equations. Mantle convection is accompanied by phase transitions and chemical reactions, which play a decisive role in the structure of mantle flows. Based on geophysical sounding data, the results of thermophysical experiments and analytical and numerical calculations, scientists are trying to detail the structure of mantle convection, find flow velocities and other important characteristics of deep processes. This data is especially important for understanding the structure of the deepest parts of the Earth - the lower mantle and core, which are inaccessible for direct study, but undoubtedly have a huge impact on the processes occurring on the surface of the planet.

Geochemical approach. For geochemistry, plate tectonics is important as a mechanism for the continuous exchange of matter and energy between the different layers of the Earth. Each geodynamic setting is characterized by specific rock associations. In turn, these characteristic features can be used to determine the geodynamic environment in which the rock was formed.

Historical approach. In terms of the history of planet Earth, plate tectonics is the history of continents joining and breaking apart, the birth and decline of volcanic chains, and the appearance and closure of oceans and seas. Now for large blocks of the crust the history of movements has been established in great detail and over a significant period of time, but for small plates the methodological difficulties are much greater. The most complex geodynamic processes occur in plate collision zones, where mountain ranges are formed, composed of many small heterogeneous blocks - terranes. When studying the Rocky Mountains, a special direction of geological research arose - terrane analysis, which incorporated a set of methods for identifying terranes and reconstructing their history.

For more information on this topic, see: Ancient continents.

For more information on this topic see: History of plate movement.

Reconstructing past plate movements is one of the main subjects of geological research. With varying degrees of detail, the position of the continents and the blocks from which they were formed has been reconstructed up to the Archean.

From an analysis of the movements of the continents, an empirical observation was made that every 400-600 million years the continents gather into a huge continent containing almost the entire continental crust - a supercontinent. Modern continents were formed 200-150 million years ago, as a result of the breakup of the supercontinent Pangea. Now the continents are at a stage of almost maximum separation. The Atlantic Ocean is expanding and the Pacific Ocean is closing. Hindustan is moving north and crushing the Eurasian plate, but, apparently, the resource of this movement is almost exhausted, and in the near geological time a new subduction zone will arise in the Indian Ocean, in which the oceanic crust of the Indian Ocean will be absorbed under the Indian continent.

The influence of plate movements on climate

The location of large continental masses in the subpolar regions contributes to a general decrease in the temperature of the planet, since ice sheets can form on the continents. The more widespread glaciation is, the greater the planet's albedo and the lower the average annual temperature.

In addition, the relative position of the continents determines oceanic and atmospheric circulation.

However, a simple and logical scheme: continents in the polar regions - glaciation, continents in the equatorial regions - increase in temperature, turns out to be incorrect when compared with geological data about the Earth's past. Quaternary glaciation actually happened when Antarctica was in the region of the South Pole, and in the northern hemisphere, Eurasia and North America approached the North Pole. On the other hand, the strongest Proterozoic glaciation, during which the Earth was almost completely covered with ice, occurred when most of the continental masses were in the equatorial region.

In addition, significant changes in the position of the continents occur over a period of about tens of millions of years, while the total duration of ice ages is about several million years, and during one ice age cyclical changes of glaciations and interglacial periods occur. All of these climate changes occur quickly compared to the speed of continental movement, and therefore plate movement cannot be the cause.

From the above it follows that plate movements do not play a decisive role in climate change, but can be an important additional factor “pushing” them.

The meaning of plate tectonics

Plate tectonics has played a role in earth sciences comparable to heliocentric a concept in astronomy, or the discovery of DNA in genetics. Before the adoption of the theory of plate tectonics, earth sciences were descriptive in nature. They achieved a high level of perfection in describing natural objects, but rarely could explain the causes of processes. Opposite concepts could dominate in different branches of geology. Plate tectonics connected the various earth sciences and gave them predictive power.

Many of you - even those who only occasionally see quarries, road cuts or cliffs on the seashore - have noticed dramatic changes in the structure of rocks. In some places you can see how rocks of one type abut rocks of a completely different type, separated from them by a narrow line of contact. In other places, strata of the same rock have undoubtedly experienced displacement, vertical or horizontal. Such sudden changes in geological structure are called faults. In Fig. 1 clearly distinguishes the vertical displacement of rock layers along a fault exposed in the wall of the Corinth Canal in Greece.

The length of faults can vary from several meters to many kilometers. Working in the field, geologists find many tectonic boundaries in the structure of rocks, which they interpret as faults and plot on geological maps as solid or broken lines. The presence of such faults indicates that at some time in the past certain movements occurred along them. We now know that such movements can be either slow sliding, which does not produce any vibrations of the ground, or sharp tearing up, causing noticeable vibrations - earthquakes. In the previous chapter, we looked at one of the most famous examples of sharp movement along a fault - the rupture of the San Andreas Fault in April 1906. However, the trace of a rupture on the surface observed during most shallow earthquakes is much smaller in size, and the displacement is much smaller. In most earthquakes, the resulting rupture does not reach the surface and therefore cannot be directly seen.

Fractures found on the surface sometimes extend to considerable depths inside the outer shell of the Earth; this shell is called the earth's crust. It is a stone shell with a thickness of 5 to 40 km and makes up the upper part of the lithosphere.

It must be emphasized that along most faults plotted on geological maps, movements no longer occur*). The last displacement along a typical such fault could have occurred tens of thousands or even millions of years ago. The local stresses that caused the destruction of rocks in a given place on Earth may have long since weakened, and chemical processes, including the circulation of water, could heal the resulting fractures, especially at depth. Such inactive faults do not become sources of earthquakes and, perhaps, never will.

Our main attention is, of course, drawn to active faults along which displacements of blocks of the earth's crust can occur. Many of these faults are located in fairly distinct tectonically active areas of the Earth, such as mid-ocean ridges and young mountain ranges. However, a sudden revival of faults can also occur far from areas with currently clearly visible tectonic activity *).

Geological analysis methods can be used to determine some properties of faults. For example, episodic movements along faults that have occurred in recent millennia leave traces in the relief such as depression lakes, lines of springs, and fresh fault ledges. Many topographic features of the San Andreas fault zone can be seen in Fig. Chapter 1 2. But it can be much more difficult to accurately establish the sequence and time of such movements. Some information of a chronological nature can be obtained from such facts as the displacement of overlying soils and young sedimentary deposits. Drilling trenches several meters deep across faults has also proven to be an effective means of studying displacements. Even the smallest movements in the layers on either side of the trench can be mapped, and the time intervals between fault movements can be inferred from the age and properties of the rocks that were displaced (Fig. 2). Sometimes the actual time of movement can be estimated from the known age of buried organic material, say leaves or branches. Even on the seafloor, faults can be mapped quite accurately using modern geophysical techniques. Research vessels at sea record sound waves reflected from layers of silt, and the resulting recordings show displacements of these layers, which can be considered faults.

1 - crack filled with clay, silt and sandy material; 2-layer A: thin grit of limestone-shell rocks - the youngest sediments of Lake Cahuilla; 3-massive light brown clays and silts containing rare remains of mollusks and thin, highly carbonated layers; 4-light gray-green carbonate silts with numerous shellfish; 5-foliate cross-bedded and massive clays, silts, sands, in places with lenses of pebbles, rare remains of mollusks everywhere; 6-geological boundaries (approximately drawn areas are shown with dashes); 7-cracks (dashed lines indicate the expected position).

Both on land and under ocean waters, displacements along faults can be divided into three types, as shown in Fig. 3. The rupture plane intersects the horizontal surface of the soil along the

direction, going at some angle to the north. This angle is called the strike angle of the fault. The fault plane itself is usually not vertical and goes deep into the Earth at a certain angle. If the rocks on the side of the fault that hangs over the crack (they say: on the hanging side of the fault) move down and are lower than on the opposite side, then we have a fault. The dip angle of the fault varies from 0 to 90°. If the hanging side of the fault is displaced upward relative to the lower, overlying side, then such a fault is called a reverse fault. Reverse faults with low dip angles are called thrust faults. The faults that occur in the foci of earthquakes in the area of ​​ocean ridges are predominantly normal faults, and in deep-sea trenches many earthquakes associated with movements such as thrust faults occur.

Both faults and reverse faults are characterized by vertical displacements, which on the surface look like structural ledges; the movement in both cases occurs along the dip (or uplift) of the fault plane. If, on the contrary, only horizontal displacements along the strike are associated with the fault, then such faults are called strike-slip faults. It is useful to agree on some simple terms that would talk about the direction of the displacements. For example, in Fig. 3 arrows on the shift diagram show that the movement was directed to the left. It is not difficult to determine whether the shift was left- or right-sided. Imagine standing on one side of a fault and looking at the other side. If the opposite side is shifted from right to left, it is a left-hand (left) shift, but if it is from left to right, it is a right-hand (right) shift. Of course, displacement along a fault can have both components: both along the dip and along the strike (such faults are called normal-slip or reverse-slip faults).

During an earthquake, serious damage can occur not only as a result of ground vibrations, but also as a result of the displacement along the fault itself, although this special type of seismic hazard has a very limited area distribution. This hazard can usually be avoided by obtaining timely (before construction) geological advice on the location of active faults. Areas on either side of an active fault are often left undeveloped and used for public recreation, golf courses, parking lots, roads, etc.

When planning land use, it is also necessary to take into account that in areas adjacent to an opened fault, the nature of destruction caused by the sliding and collapse of the soil depends on the type of fault. If the displacement occurs along the dip of the fault, then the appearance of the ledge is associated with destruction (due to local phenomena of sliding, cracking and collapse of the soil) in a fairly wide strip running along the fault itself. If displacement occurs along the strike of the fault, the zone of disturbance in the ground is usually much less wide, and buildings located only a few places from the fault may experience no damage at all.

The record-breaking earthquake and subsequent tsunami that hit Japan early Friday is a stark reminder of the devastating natural disasters that can strike populated cities - especially those in high-risk areas such as along major fault lines. earth's crust.
Take a look at the five cities that are most at risk from such disasters due to their location.
Tokyo, Japan
Built precisely at the triple intersection of three major tectonic plates - the North American Plate, the Philippine Plate and the Pacific Plate - Tokyo is constantly in motion. The city's long history and familiarity with earthquakes has pushed it to create maximum levels of tectonic protection.

Tokyo is by far the city most prepared for earthquakes, which means we're probably underestimating the potential damage nature can cause.
Faced with a magnitude 8.9 earthquake, the strongest earthquake in Japanese history, Tokyo, 370 km from the epicenter, went into an automated shutdown mode: elevators stopped working, the subway stopped, people had to walk many kilometers in the cold night to get to their houses outside the city, where the greatest destruction occurred.
The 10-metre tsunami that followed the earthquake washed away hundreds of bodies on the north-east coast, leaving thousands of people missing.

Istanbul, Türkiye
Seismologists have long been monitoring the so-called “living” faults, one of which is the North Anatolian fault. It stretches for almost 1,000 kilometers - mainly through the territory of modern Turkey - and is located between the Eurasian and Anatolian plates. The shear rate in the area of ​​their contact reaches 13-20 mm/year, but the total amount of movement of these plates is higher - up to 30 mm/year. The city is a melting pot of rich and poor infrastructure, putting a huge portion of its 13 million residents at risk. In 1999, a magnitude 7.4 earthquake hit the city of Izmit, just 97 km from Istanbul.
While older buildings such as mosques survived, newer 20th-century buildings, often built from concrete mixed with salty groundwater and with disregard for local building codes, turned to dust. About 18,000 people died in the region.
In 1997, seismologists predicted that there was a 12% chance that the same earthquake could occur again in the region before 2026. Last year, seismologists published in the journal Nature Geoscience that the next earthquake was likely to occur in the west of Izmit along the fault - dangerous 19 km south of Istanbul.

Seattle, Washington
When residents of the Pacific Northwest city think of disasters, two scenarios come to mind: a megaquake and the eruption of Mount Rainier.
In 2001, the Nisqually Indian Territory earthquake prompted the city to improve its earthquake preparedness plan, and several new improvements were made to building codes. However, many older buildings, bridges and roads have still not been updated to meet the new code.
The city lies on an active tectonic boundary along the North American Plate, the Pacific Plate, and the Juan de Fuca Plate. The ancient history of both earthquakes and tsunamis is recorded in the soil of the petrified flood forests, as well as in the oral histories passed down through generations of Pacific Northwest Native Americans.
Looming vaguely in the distance, and when the cloud cover is high enough, the impressive view of Mount Rainier reminds us that this is a dormant volcano and at any time it could push up Mount St. Helens as well.
Although seismologists are extremely good at monitoring volcanic tremors and warning authorities when an eruption is imminent - last year's eruption of Iceland's Eyjafjallajökull volcano showed that the extent and duration of the eruption is just anyone's guess. Most of the devastation will affect the east of the volcano.
But if an uncharacteristic northwest wind blows, the Seattle airport and the city itself will encounter large amounts of hot ash.

Los Angeles, California
Disasters are nothing new to the Los Angeles area - and not all of them are talked about on TV.
Over the past 700 years, powerful earthquakes have occurred in the region every 45-144 years. The last major earthquake with a magnitude of 7.9 occurred 153 years ago. In other words, Los Angeles is about to experience the next big earthquake.
Los Angeles, with a population of about 4 million, could experience strong tremors during the next major earthquake. According to some estimates, taking into account all of Southern California, with a population of about 37 million people, a natural disaster could kill between 2,000 and 50,000 people and cause billions of dollars in damage.

San Francisco, California
San Francisco, with a population of more than 800,000 people, is another large city on the West Coast of the United States that could be devastated by a powerful earthquake and/or tsunami.
San Francisco is located near, although not exactly on the northern part of the San Andreas Fault. There are also several related faults running parallel across the San Francisco region, increasing the likelihood of an extremely destructive earthquake.
There has already been one such disaster in the history of the city. On April 18, 1906, San Francisco was hit by an earthquake measuring between 7.7 and 8.3. The disaster killed 3,000 people, caused half a billion dollars in damage and leveled much of the city.
In 2005, earthquake expert David Schwartz, a resident of San Francisco, estimated that there was a 62% chance that the region would experience a major earthquake within the next 30 years. Although some buildings in the city are built or reinforced to withstand an earthquake, many are still at risk, according to Schwartz. Residents are also advised to keep emergency kits with them at all times.

The comparison of the Middle East problem with such a phenomenon as a tectonic shift, made by the Director of the Department of Information and Press of the Ministry of Foreign Affairs of the Russian Federation, Maria Zakharova, was very puzzling and even frightened almost all foreign television channels. Her statement was seen not only as a challenge, but also as a threat to NATO and the United States.

Apocalypse as such

For readers who have not seen the film "San Andreas Fault," this article explains in detail what a tectonic shift is and how to apply this concept to the political landscape of today. The extent to which this phenomenon threatens humanity is explained even by the enormous interest that is observed in the world towards the possibility of an imminent apocalypse.

The causes of its onset are considered to be lightly dormant supervolcanoes, the Third World War with the subsequent nuclear winter, and, of course, a tectonic shift. Humanity is so worried about its fate that even a simple comparison with this geological area from the lips of a political figure received enormous resonance in the world media.

About tramps

Geologists easily read the chronicles of centuries and even millennia. From them we know that sandy desert soils are stored in huge deposits in the south of England, the remains of ancient giant ferns have been discovered in Antarctica, and in Africa there are clear traces of the glaciers that covered it. This suggests that geological epochs also changed climate. The shift intensified volcanic activity, ash obscured the sun, rising into the upper atmosphere for many years, and a long winter began. Ice ages killed most of all life on Earth. For example, only less than fifteen percent of bird species remained after the last glaciation, and it is difficult to imagine that their current diversity is a pitiful remnant of its former splendor.

There are many widely varying scientific explanations for the causes of global change. One of them, the most widespread and most conclusive, says that the continents do not stand still. A small example clearly shows what a tectonic shift means. If you apply the east of South America to the west of Africa, they will fit together with virtually no gaps. This means that they were not always separated by the Atlantic Ocean. There are many such examples. And the fact that America will face terrible tectonic shifts is not a threat from the lips of Maria Zakharova. This is what nature promises. And, since Hollywood has already flooded the cinema with many hundreds of films about the imminent end of the world, where they even go into action, it means that Americans fully anticipate and understand the impending danger.

Tectonic shift

The definition of this phenomenon was given long ago and precisely: it is a fracture of a single solid continental plate located under the earth’s crust. How do tectonic plate faults threaten humanity? The scenario is this: one, even a small fault will engulf the planet in a chain reaction. Melted glaciers will release the plates from the pressure of their enormous mass, the earth's crust will rise, and ocean water will pour into the depths of the faults. The magma under the crust is hot - about one thousand two hundred degrees Celsius. Steam with basalt dust and gas will be ejected from underground with enormous force and everywhere. Rainfalls will begin - unprecedented, akin to a flood. Volcanoes will wake up - all of them. After which an indescribable tsunami will sweep away everything from the face of the planet. There is enough time for the entire situation from the beginning of the fault to the volcanic eruptions; you can even run away if you find somewhere. After the tsunami begins, the earth will be empty within a matter of hours.

The continents we inhabit were formed two hundred million years ago, when Pangea, the hypercontinent, split apart. The scattered tramps have “taken root” at approximately equal distances from each other, but they are still drawn to each other. Scientists predict that in about fifty million years they will reunite. In the 70s of the last century, a model of the supposed movement of continents was created. It turns out that the Pacific plate is moving quite quickly towards the North American tectonic plate. The San Andreas tectonic shift threatens right at the junction of these two plates. There are frequent earthquakes of destructive force, which happened in San Francisco and Los Angeles just a hundred years ago. America is terribly afraid of geological disasters, which is why Maria Zakharova’s words were perceived as if Russia was threatening the United States with tectonic shifts. What exactly did the director of the department mean?

To the history of the issue

Of course, this was a warning about the threat, but “terrible tectonic shifts” were not promised from Russia (Zakharova quote). They will happen if the United States insists on replacing Syrian leader Assad, who is fighting the Islamic State. Then radical Islamists and terrorists, with whom America is already very familiar, will inevitably come to power. The events of Iraq in 2003 and Libya in 2011 (after the overthrow of Saddam Hussein and Muammar Gaddafi) speak for themselves. The Islamic State will inevitably grow and become much stronger. This is precisely what the Russian Foreign Ministry constantly signals. Then the rampant terrorism may well exceed the dangers that tectonic shifts bring with them. Zakharova was told exactly this, but the conclusions that followed were absolutely incorrect.

The Middle East did not gain stability in 2016, negative developments continue there: bloodshed in Syria, lack of stabilization in Libya, riots of the Kurdish autonomy in Iraq, the Yemen conflict has worsened, Saudi Arabian rebels have been inflicting increasingly serious blows on the economy and financial situation of the country for many years leading military operations, got involved in Middle Eastern conflicts. It is from the Middle East that all tectonic shifts in politics are coming. The situation is a crisis in all respects, and this crisis is rapidly expanding, chaos is growing, waves of refugees are sweeping Europe, creating a security threat and huge problems there. The year has ended, and it did not bring any solutions. If the last bastion of the fight against terrorists, the “dictator” Bashar Assad, lays down his arms, the “tectonic shifts” of 2016 will sweep the whole world.

Methods of warfare

Daesh continues to build up its military potential, and, despite the beginning of the liberation of territories, the Iraqi army with its US and coalition supporters did not have an easy walk through the suburbs of Mosul. The threat of terrorism is not only not eliminated, it is growing, and therefore very special, truly serious efforts on a global scale are required by forces united in this fight for the complete victory of this evil. The level of US influence on the Middle East situation has decreased, and it has decreased quite significantly. The current administration is leaving, as if deliberately weakening the potential and capabilities of its own country in this region; it is now impossible to admit that the United States is the leading player in the Middle East. And the change of power there is taking place in an environment that itself is capable of starting tectonic shifts in America (and this is not about geological faults).

But Russia distinguished itself in the Middle East in 2016, significantly expanding the circle of partners, including Egypt, Israel and Bahrain, making progress in cooperation with Qatar, agreeing with OPEC to limit the level of oil produced (even managed to get along with Saudi Arabia), normalizing relations with Turkey . A new team has been formed to resolve the situation in Syria, ousting the United States from the region. These are Iran, Türkiye and Russia. The Russian Aerospace Forces are seriously helping the Syrian army win victories over terrorists. Aleppo liberated. All this is regarded by the world as purely Russian political victories. That is why Maria Zakharova spoke so brightly and colorfully about tectonic shifts. The loss of a partner like Bashar al-Assad will reduce these victories to zero. Moreover, until the Islamic State is completely exsanguinated, our diplomats see the current situation as quite precarious.

Crimea and the Middle East

To take a little break from pressing political problems, let’s return to the issue of geological faults and continental plates, since more and more information appears every day, and from time to time it looks like a curiosity, despite all its reliability. Scientists from different countries studying geological layers deep in the earth's crust have identified a shift in tectonic plates, as a result of which tectonic activity is observed in the Middle East and neighboring regions.

Full member of the Russian Academy of Sciences Alexander Ipatov announced the latest reliable research results (including applied astronomy). Sensation: the Crimean peninsula is gradually moving closer to Russia. After all, the plate did not float towards Turkey or Greece, the tectonic shift of Crimea is geologically directed home. The meeting of the peninsula with the mainland, however, will not happen so soon; it will have to wait several tens of millions of years. But the republics have met together since 2014.

World politics and tectonic shifts in it

The results of the past year can be fully summed up only when the upcoming policy of the new United States administration - both in the Middle East and in the world in general - becomes clear. However, the contradictions between the Islamic world and Western countries are unlikely to be eliminated soon, and the growth of xenophobia will most likely continue, which, of course, can poison the entire system of relations in both the Islamic and non-Islamic worlds. All year we have observed huge changes in world politics, which were quite akin to tectonic shifts in their significance.

First of all, we need to mention Brexit, which thoroughly shook the world, when Great Britain decided to leave the European Union. Then came the unexpectedly convincing victory of Donald Trump in the US presidential election, which not only no one planned, but also did not allow the slightest thought about such a turn of events. If we add to this the significantly strengthened right in European countries (primarily in France and Germany), then the progress seems irreversible; it is unlikely that they will stop developing in 2017.

Center of gravity

The value spectrum of the entire Western part of the world has shifted greatly, as right-wing conservative, populist and nationalist waves have made the palette of moods of society much more diverse, adding completely unexpected new tones. Protest sentiments appear even where they have never existed, in countries for which this is completely uncharacteristic. They write about what is starting in the United States, about the abrupt change of regime in Western European countries. gradually becomes unpredictable, filled with new, never-before-happened events and phenomena that need to be comprehended.

The center of gravity of the entire world political system is clearly shifting. Asian countries are becoming stronger; the share of China and India has risen exceptionally high. Therefore, the main intrigues of this tectonic shift in politics will most likely unfold in relations between China and the United States. The economic crisis that has gripped the world is also hard for the leading countries. The people of the United States are gripped by general disappointment in the policies of the ruling party. That is why the Republicans won such a convincing victory over the Democrats, won a majority of seats in the House of Representatives and increased their representation in the Senate.

Internal and external policy

Trump's victory is important not so much for domestic policy as for foreign policy. Israel is already clearly excited, China is concerned, the rest of Asia is upset, and Russia is speculating. A much tougher position towards China is quite possible - a weakening of the yuan until it is impossible to maintain its own currency. Support for the Afghan war is very possible. Republicans are also concerned about the country's missile defense deployment.

Congress received a significant strengthening of pro-Israeli forces: Senator from Illinois - Mark Kirk, majority leader of the lower house - Eric Cantor, now Tel Aviv can hope for a special political climate that will allow the resumption of negotiations with the Palestinian Authority. At the same time, pro-Israeli forces are feeling strong pressure from forces that are still unknown (however, everyone can guess which ones): on January 19, 2017, there were reports of mining of 28 Jewish centers in 17 US states, which, fortunately, was imaginary. But this is not the first warning. And at a certain moment, mining may not be false.

How will it end?

It seems to many that America’s stable position in the world has been shaken, and its global dominance has almost been lost. Is it so? The President of Russia is also very cautious in his assessments. Indeed, remember 2010, when WikiLeaks opened and made public tens of thousands of documentary letters from the American diplomatic post. It seemed - well, that’s it, the end of the power. But nothing happened to America. The allies, even when substituted in every possible way, were not lost. The enemies also remained in place, no new ones were added. One thing is surprising: no one thought to blame Moscow for these revelations, as happened after Donald Trump won the election.

Yes, Trump is different. He is significantly different from the previous president. But who knows what awaits Russia in connection with this choice? If you look from Moscow or some Skovorodin, the Republicans are seen as people who are more pragmatic and less dangerous for us than the defeated Democrats, who constantly did minor and major mischief to the Russians. How different is Trump's team from Hillary Clinton's team? After thoughtful analysis, it becomes clear that the actions of both parties are unfolding on the same lithospheric platform. They are much more similar than seen from afar. Both teams intimidate the people with an external threat and paint a picture of various foreign intrigues. Freedom and democracy are respected by some, prestige and economics by others, but both are threatened by external forces; in any case, the nation is in danger. Hillary did not like global populism and Russia, and Trump does not like multinational corporations, Mexico, China and developing countries. A tectonic shift in politics is inevitable. This is probably why our diplomats are so cautious in their assessments and forecasts.