SEISMICITY The susceptibility of a given area to earthquakes, characterized by the distribution and recurrence of earthquakes of different strengths over time and the nature of destruction

(Bulgarian; Bulgarian) - seismicity

(Czech; Čeština) - seismicita

(German language; Deutsch) - seismik

(Hungarian; Magyar) - szeizmicitas

(Mongolian) - Gazar Khödlölt

(Polish language; Polska) - sejsmiczność

(Romanian; Român) -seismicitate

(Serbo-Croatian; Srpski jezik; Hrvatski jezik) - seismicnost

(Spanish; Español) - sismicidad

(English language; English) -seismicity

(French language; Français) - s(e)ismicite

Construction dictionary.

See what "SEISMICITY" is in other dictionaries:

seismicity- probable earthquake intensity in points on the MSK 64 scale. Source: RD 31.3.06 2000: Guidelines for accounting for seismic waters ... Dictionary-reference book of terms of normative and technical documentation

seismicity- Exposure of the Earth or certain territories to earthquakes. Note Seismicity is characterized by the territorial distribution of sources, intensity and other characteristics of earthquakes. [RD 01.120.00 KTN 228 06] seismicity ... ... Technical Translator's Handbook

1) the possibility and frequency of occurrence of an earthquake with a certain intensity; 2) the distribution in space and time of earthquake sources of various amplitudes, due to tectonic movements of the rocks of the earth's crust and upper mantle ... ... Emergencies Dictionary

Exist., number of synonyms: 2 high seismicity (1) susceptibility to earthquakes (1) Dictionary of synonyms ... Synonym dictionary

Manifestation of earthquakes. S. of the region is characterized by the distribution of earthquakes over the area, the frequency of earthquakes of different strengths in time, the nature of destruction and deformation and the area of ​​​​destruction, the connection of earthquake sources with geol. ... ... Geological Encyclopedia

seismicity- a set of earthquake sources in space and time ... Source: DECISION of the Gosatomnadzor of the Russian Federation of December 28, 2001 N 16 ON THE APPROVAL AND INTRODUCTION OF THE SAFETY GUIDE SEISMIC HAZARD ASSESSMENT OF NUCLEAR AND ... Official terminology

seismicity- The susceptibility of the Earth or individual territories to earthquakes, determined by their intensity and frequency in a given region. Syn.: seismic activity… Geography Dictionary

Seismic terminology is a set of the most important terms and concepts used in the practice of anti-seismic design of power equipment and pipelines of nuclear and thermal power plants. Antiseismic design complex ... ... Wikipedia

G. Earthquake susceptibility. Explanatory Dictionary of Ephraim. T. F. Efremova. 2000... Modern dictionary Russian language Efremova

Seismicity, seismicity, seismicity, seismicity, seismicity, seismicity, seismicity, seismicity, seismicity, seismicity, seismicity, seismicity (Source: “Full accentuated paradigm according to A. A. Zaliznyak”) ... Forms of words

Books

• Statistical hydrometeorology. Part 2. Turbulence and waves. Textbook, V. A. Rozhkov. The second part of `Statistical Hydrometeorology` (the 1st part - `Turbulence and Waves` - was published by St. Petersburg State University in 2013) discusses the regularities of multiscale variability…
• Modern methods of measurement, processing and interpretation of electromagnetic data. Electromagnetic sounding of the Earth and seismicity , Spichak V.V.

From the newspaper "Construction Expert", December 1998, No. 23

"... Particularly acute problems associated with the reliability of houses arise during construction in areas with increased seismic activity. For Russia, these are the Far East and the North Caucasus. For many CIS countries, seismic areas are their entire territory or a significant part of it.

Of course, it is impossible to take all individual construction under qualified control. Another way is the creation of very attractive construction technologies that make it possible to ensure a high safety margin of the buildings under construction with comfortable living in them in any conditions ... TISE can be attributed to such a technology ... "

We are interested in the nature of earthquakes, their physical parameters and degree of impact on structures.

The main causes of earthquakes are the movement of blocks and plates of the earth's crust. In essence, the Earth's crust is plates floating on the surface of a liquid magma sphere. Tidal phenomena, caused by the attraction of the Moon and the Sun, disturb these plates, which is why high stresses accumulate along the lines of their junction. Reaching a critical value, these stresses are released in the form of earthquakes. If the earthquake source is on the mainland, then severe destruction occurs in the epicenter and around it, but if the epicenter is in the ocean, then crustal movements cause a tsunami. In the zone of great depths, this is a barely noticeable wave. Near the coast, its height can reach tens of meters!

Often the cause of ground vibrations can be local landslides, mudflows, man-made failures caused by the creation of cavities (mining, water intake from artesian wells ...).

In Russia, a 12-point scale for assessing the strength of an earthquake has been adopted. The main feature here is the degree of damage to buildings and structures. The zoning of the territory of Russia according to the point principle is given in building codes (SNiP 11-7-81).

Almost 20% of the territory of our country is located in seismically dangerous zones with earthquake intensity of 6-9 points and 50% are subject to 7-9-point earthquakes.

Taking into account the fact that TISE technology is of interest not only in Russia, but also in the CIS countries, we present a map of the zoning of Russia and neighboring countries located in seismically active zones (Figure 181).

Figure 181. Map of seismic zoning of Russia and neighboring countries

The following seismically dangerous zones are distinguished on the territory of our country: the Caucasus, the Sayan mountains, Altai, the Baikal region, Verkhoyansk, Sakhalin and Primorye, Chukotka and the Koryak highlands.

Construction in seismically hazardous areas requires the use of structures of increased strength, rigidity and stability, which causes an increase in the cost of construction in the 7-point zone by 5%, in the 8-point zone - by 8% and in the 9-point zone - by 10%.

Some features of seismic loading of building elements:

- during an earthquake, the building is exposed to several types of waves: longitudinal, transverse and surface;

- the greatest destruction is caused by horizontal vibrations of the earth, with which the destructive loads are of an inertial nature;

– the most characteristic periods of soil oscillations lie in the range of 0.1 – 1.5 sec;

- the maximum accelerations are 0.05 - 0.4 g, and the greatest accelerations occur in periods of 0.1 - 0.5 seconds, which correspond to the minimum oscillation amplitudes (about 1 cm) and the maximum destruction of buildings;

– a long period of oscillations corresponds to minimum accelerations and maximum amplitudes of soil oscillations;

- reducing the mass of the structure leads to a decrease in inertial loads;

- vertical reinforcement of the walls of the building is advisable in the presence of horizontal load-bearing layers in the form of, for example, reinforced concrete floors;

Seismic isolation of buildings is the most promising way to increase their seismic resistance.

This is interesting

The idea of ​​seismic isolation of buildings and structures arose in ancient times. During archaeological excavations in Central Asia, reed mats were found under the walls of Heck buildings. Similar designs were used in India. It is known that the 1897 earthquake in the Shillong region destroyed almost all stone buildings, except for those built on seismic shock absorbers, although of a primitive design.

The construction of buildings and structures in seismically active regions requires complex engineering calculations. Earthquake-resistant structures built by industrial methods undergo deep and comprehensive studies and complex calculations involving a large number of specialists. For an individual developer who decides to build his own house, such expensive methods are not available.

The TISE technology offers an increase in the seismic resistance of buildings erected under individual construction conditions in three directions at once: reducing inertial loads, increasing the rigidity and strength of walls, as well as introducing a seismic isolation mechanism.

The high degree of hollowness of the walls can significantly reduce inertial loads on the building, and the presence of through vertical voids makes it possible to introduce vertical reinforcement, organically integrated into the design of the walls themselves. For other technologies of individual construction, this is quite difficult to accomplish.

The seismic isolation mechanism is a columnar-strip foundation erected using TISE technology.

A 20 mm carbon steel rod is used as vertical reinforcement of the foundation column, which passes through the grillage. The rod has a smooth surface covered with tar. From below, it is equipped with an ending embedded in the body of the column, and from above - with an ending protruding from the grillage and equipped with an M20 thread for a nut (RF patent No. 2221112 of 2002). The support itself is included in the grillage array by 4 ... 6 cm (Figure 182, a).

After concreting around each of the supports, the same foundation drill makes three or four cavities 0.6 ... 0.8 m deep and fill them with either sand, or a mixture of sand with expanded clay, or slag. In sandy soil, such cavities can be omitted.

Figure 182. Seismic isolation foundation with a central bar:
A - the neutral position of the foundation support; B - deviated position of the foundation support;
1 - support; 2 - bar; 3 - bottom ending; 4 - nuts; 5 - grillage; 6 - cavity with sand; 7 - blind area; 8 - directions of ground vibrations

Upon completion of construction, the nuts of the bars are tightened with a calibrated wrench. So in the zone of the junction of the column with the grillage, an "elastic" hinge is created.

With horizontal vibrations of the soil, the pillars deviate relative to the elastic hinge, the bar is stretched, while the grillage with the building remains motionless by inertia (Figure 182, b). The elasticity of the soil and rods returns the pillars to their original vertical position. During the entire period of operation of the building, a free approach should be provided to the tension nodes of the reinforcement of the pillars both along the outer perimeter of the house and under the internal load-bearing walls. After completion of construction and after significant seismic vibrations, the tightening of all nuts is restored with a torque wrench (M = 40 - 70 kg / m). This version of the Seismic Isolation Foundation can be considered industrial to some extent, since it includes rods and nuts that are easier to manufacture in production.

The TISE technology provides for the implementation of seismic isolation supports in a more democratic way, accessible to developers with limited production capabilities. As a reinforcing elastic element, two brackets from a reinforcement bar with a diameter of 12 mm with bent ends are used (Figure 183). The middle part of the reinforcement branches over a length of about 1 m is lubricated with tar or bitumen (at an equal distance from the edges) to prevent adhesion of the reinforcement to concrete. With seismic vibrations of the soil, the reinforcement bars in their middle part are stretched. With horizontal soil displacements of 5 cm, the reinforcement is stretched by 3 ... 4 mm. With a tensile zone length of 1 m, stresses of 60...80 kg/mm² arise in the reinforcement, which lies in the zone of elastic deformations of the reinforcement material.

Figure 183. Seismic isolation foundation with reinforcing brackets:
1 - support; 2 - bracket; 3 - grillage; 4 - cavity with sand

When building a house in seismically active zones, waterproofing at the connection of the grillage with the walls is not done (to exclude their relative displacement). According to TISE technology, waterproofing is performed at the junction of the grillage with foundation pillars (two layers of roofing material on bituminous mastic).

During the construction of adjacent structures, a porch, blind area elements, etc., you should constantly pay attention to the fact that the foundation tape does not touch them with its side surface. The gap between them should be at least 4 - 6 cm. If necessary, such contact is allowed (with a porch, a frame of light panel outbuildings, a veranda) on the assumption that after destruction by an earthquake they will be restored.

It's not the foundation, but...

When building in seismically active areas, the use of a roof made of clay or sand concrete tiles should be justified.

Many japanese houses individual buildings, having a light frame, are covered with solid clay tiles. In the conditions of dense Japanese buildings, such houses tolerate typhoons well. However, during an earthquake, under the weight of a tiled roof, the house collapses, burying the inhabitants under its exorbitant weight.

Currently, a lot of "light" roofing materials have appeared on the construction market that imitate tiles well. Light roofing is the minimum inertial loads for connecting the roof to the walls and preventing the roof from collapsing due to its excessive weight.

seismic(from the Greek - concussion) phenomena manifest themselves in the form of elastic vibrations of the earth's crust. This formidable natural phenomenon is typical of geosyncline regions, where modern mountain building processes are active, as well as subduction and obduction zones.

Seismic tremors occur almost continuously. Special instruments register more than 100 thousand earthquakes during the year, but, fortunately, only about 100 of them lead to devastating consequences, and some lead to catastrophes with loss of life, massive destruction of buildings and structures (Fig. 45).

Earthquakes also occur in the process of volcanic eruptions (in Russia, for example, in Kamchatka), the occurrence of failures due to the collapse of rocks in large underground caves, narrow deep valleys, and also as a result of powerful explosions produced, for example, for construction purposes. The destructive effect of such earthquakes is small and they are of local importance, and the most destructive are tectonic seismic phenomena, which, as a rule, capture large areas.

History knows catastrophic earthquakes when tens of thousands of people died and entire cities or most of them were destroyed (Lisbon - 1755, Tokyo - 1923, San Francisco - 1906, Chile and the island of Sicily - 1968). Only in the first half of the XX century. there were 3749 of them, while only in the Baikal region there were 300 earthquakes. The most destructive - in the cities of Ashgabat (1948) and Tashkent (1966).

An exceptional catastrophic earthquake occurred on December 4, 1956 in Mongolia, which was also recorded in China and Russia. It was accompanied by great destruction. One of the mountain peaks split in half, part of the mountain 400 m high collapsed into the gorge. A fault depression up to 18 km long and 800 m wide was formed. Cracks up to 20 m wide appeared on the surface of the earth. The main of these cracks stretched up to 250 km.

The most catastrophic was the 1976 earthquake that occurred in the city of Tangshan (China), as a result of which 250 thousand people died, mainly under collapsed buildings made of clay (adobe brick).

Tectonic seismic phenomena occur both at the bottom of the oceans and on land. In this regard, a distinction is made between seaquakes and earthquakes.

Seaquakes arise in the deep oceanic depressions of the Pacific, less often the Indian and Atlantic oceans. Rapid uplifts and subsidences of the ocean floor cause displacement of large masses of rocks and on the surface of the ocean generate gently sloping waves (tsunamis) with a distance between crests of up to 150 km and a very small height above the great depths of the ocean. When approaching the shore, along with the rise of the bottom, and sometimes the narrowing of the coast in the bays, the height of the waves increases to 15-20 m and even 40 m.

Tsunami move over distances of hundreds and thousands of kilometers at a speed of 500-800 and even more than 1000 km / h. As the depth of the sea decreases, the steepness of the waves increases sharply and they fall on the shores with terrible force, causing the destruction of structures and the death of people. During the seaquake of 1896 in Japan, waves 30 m high were noted. As a result of hitting the coast, they destroyed 10,500 houses, more than 27 thousand people died.

Tsunamis most often affect the Japanese, Indonesian, Philippine and Hawaiian Islands, as well as the Pacific coast of South America. In Russia, this phenomenon is observed on the eastern shores of Kamchatka and the Kuril Islands. The last catastrophic tsunami in this area occurred in November 1952 in the Pacific Ocean, 140 km from the coast. Before the arrival of the wave, the sea receded from the coast at a distance of 500 m, and after 40 minutes a tsunami with sand, silt and various debris hit the coast. This was followed by a second wave up to 10-15 m high, which completed the destruction of all buildings located below the ten-meter mark.

The highest seismic wave - a tsunami rose off the coast of Alaska in 1964; its height reached 66 m, and the speed was 585 km/h.

The frequency of tsunamis is not as high as that of earthquakes. So, for 200 years, only 14 of them were observed on the coast of Kamchatka and the Kuril Islands, of which four were catastrophic.

On the coast of the Pacific Ocean in Russia and other countries, special surveillance services have been created that warn of the approach of a tsunami. This allows you to warn and shelter people from danger in time. To combat the tsunami, engineering structures are erected in the form of protective embankments, reinforced concrete piers, wave-breaking walls, and artificial shallows are created. Buildings are placed on a high part of the relief.

Earthquakes. seismic waves. The origin of seismic waves is called the hypocenter (Fig. 46). According to the depth of the hypocenter, earthquakes are distinguished: surface - from 1 to 10 km depth, cow - 30-50 km and deep (or plutonic) - from 100-300 to 700 km. The latter are already in the Earth's mantle and are associated with movements occurring in the deep zones of the planet. Such earthquakes were observed in the Far East, in Spain and Afghanistan. The most destructive are surface and crustal earthquakes.

Directly above the hypocenter on the earth's surface is epicenter. In this area, the surface shaking occurs first and with the greatest force. An analysis of earthquakes showed that in seismically active regions of the Earth, 70% of the sources of seismic phenomena are located to a depth of 60 km, but the most seismic is still a depth of 30 to 60 km.

Seismic waves radiate from the hypocenter in all directions, which by their nature are elastic vibrations. There are longitudinal and transverse seismic waves, as elastic vibrations propagating in the earth from the centers of earthquakes, explosions, impacts and other sources of excitation. Seismic waves - longitudinal, or /*-waves (lat. primae- the first), come to the surface of the earth first, as they have a speed 1.7 times greater than transverse waves; transverse, or 5-waves (lat. secondae- second), and superficial, or L-waves (lat. 1op-qeg- long). The length of L-waves is greater, and the speed is less than that of R- and 5-waves. Longitudinal seismic waves - waves of compression and tension of the medium in the direction of seismic rays (in all directions from the source of an earthquake or other source of excitation); transverse seismic waves - shear waves in the direction perpendicular to the seismic rays; surface seismic waves - waves propagating along the surface of the earth. L-waves are divided into Love waves (transverse vibrations in the horizontal plane that do not have a vertical component) and Rayleigh waves (complex vibrations that have a vertical component), named after the scientists who discovered them. Of greatest interest to a civil engineer are longitudinal and transverse waves. Longitudinal waves cause expansion and contraction of rocks in the direction of their movement. They spread in all media - solid, liquid and gaseous. Their speed depends on the material of the rocks. This can be seen from the examples given in Table. 11. Transverse oscillations are perpendicular to longitudinal ones, propagate only in a solid medium and cause shear deformations in rocks. The speed of transverse waves is approximately 1.7 times less than that of longitudinal waves.

On the surface of the earth, waves of a special kind diverge in all directions from the epicenter - surface waves, which by their nature are gravity waves (like sea waves). The speed of their spread is lower than that of the transverse ones, but they have an equally detrimental effect on structures.

The action of seismic waves, or, in other words, the duration of earthquakes, usually manifests itself within a few seconds, less often minutes. Sometimes long earthquakes are observed. For example, in Kamchatka in 1923 the earthquake lasted from February to April (195 shocks).

Table 11

The speed of propagation of longitudinal (v p) and transverse (vs) waves in various rocks and in water, km/sec

Estimation of the strength of earthquakes. Earthquakes are constantly monitored with the help of special instruments - seismographs, which make it possible to qualitatively and quantitatively assess the strength of earthquakes.

Seismic scales (column seismos- earthquake + lat. sca- la- ladder) is used to assess the intensity of oscillations (shaking) on ​​the Earth's surface during earthquakes in points. The first (close to modern) 10-point seismic scale was compiled in 1883 jointly by M. Rossi (Italy) and F. Forel (Switzerland). Currently, most countries in the world use 12-point seismic scales: "MM" in the United States (improved Mercalli-Konkani-Seeberg scale); International MSK-64 (named after the authors S. Medvedev, V. Shponheuer, V. Karnik, created in 1964); Institute of Physics of the Earth, Academy of Sciences of the USSR, etc. In Japan, a 7-point scale is used, compiled by F. Omori (1900) and subsequently revised many times. The score according to the MSK-64 scale (updated and supplemented by the Interdepartmental Council for Seismology and Earthquake-Resistant Construction in 1973) is set:

on the behavior of people and objects (from 2 to 9 points);

according to the degree of damage or destruction of buildings and structures (from 6 to 10 points);

on seismic deformations and the occurrence of other natural processes and phenomena (from 7 to 12 points).

Very famous is Richter scale, proposed in 1935 by the American seismologist Ch.F. Richter, theoretically substantiated together with B. Gutenberg in 1941-1945. magnitude scale(M); revised in 1962 (Moscow-Prague scale) and recommended by the International Association of Seismology and Physics of the Earth's Interior as a standard. On this scale, the magnitude of any earthquake is defined as the decimal logarithm of the maximum amplitude of a seismic wave (expressed in micrometers) recorded by a standard seismograph at a distance of 100 km from the epicenter. At other distances from the epicenter to the seismic station, a correction is introduced to the measured amplitude in order to bring it to the one that corresponds to the standard distance. The zero of the Richter scale (M = 0) gives the focus at which the amplitude of the seismic wave at a distance of 100 km from the epicenter will be equal to 1 micron, or 0.001 mm. When the amplitude increases by a factor of 10, the magnitude increases by one. At an amplitude less than 1 µm, the magnitude has negative values; known maximum values ​​of magnitudes M = 8.5...9. Magnitude - calculated value, relative characteristic of the seismic source, independent of the location of the recording station; is used to estimate the total energy released in the source (a functional relationship between magnitude and energy has been established).

The energy released in the focus can be expressed by the absolute value ( E, J), energy class value (K = lgE) or a conditional value called magnitude, .

The magnitude of the largest earthquakes M = 8.5...8.6, which corresponds to the release of energy or seventeenth - eighteenth energy classes. The intensity of the manifestation of earthquakes on the surface of the earth (shaking on the surface) is determined by the scales of seismic intensity and is estimated in conventional units - points. Score (I) is a function of magnitude (M), focus depth (h) and distance from the considered point to the epicenter (L):

Below are comparative characteristics of different groups of earthquakes (Table 12).

For calculations of force effects (seismic loads) exerted by earthquakes on buildings and structures, the following concepts are used: vibration acceleration (but), seismicity coefficient ( to c) and the maximum relative displacement (0.

In practice, the strength of earthquakes is measured in points. In Russia, a 12-point scale is used. Each score corresponds to a certain value of the oscillation acceleration but(mm/s 2). In table. 13 shows a modern 12-point scale and gives a brief description of the consequences of earthquakes.

Seismic regions of Russia. The entire earth's surface is divided into zones: seismic, aseismic and peneseismic. TO seismic include areas that are located in geosynclinal regions. IN aseismic There are no earthquakes in regions (Russian Plain, Western and Northern Siberia). IN peneseismic earthquakes occur relatively rarely and are of small force.

For the territory of Russia, a map of the distribution of earthquakes was compiled with an indication of the points. The seismic regions include the Caucasus, Altai, Transbaikalia, the Far East, Sakhalin, the Kuril Islands, Kamchatka. These areas occupy a fifth of the territory on which large cities are located. This map is currently being updated and will contain data on the frequency of earthquakes over time.

Earthquakes contribute to the development of extremely dangerous gravitational processes - landslides, landslides, talus. As a rule, all earthquakes of seven points and above are accompanied by these phenomena, moreover, of a catastrophic nature. The widespread development of landslides and collapses was observed, for example, during the Ashgabat earthquake (1948), a strong earthquake in Dagestan (1970), in the Chkhalta valley in the Caucasus (1963), in the valley of the river. Naryn (1946), when seismic vibrations unbalanced large massifs of weathered and destroyed rocks, which were located in the upper parts of high slopes, which caused rivers to spring up and large mountain lakes to form. Weak earthquakes also have a significant effect on the development of a landslide. In these cases, they are, as it were, a push, a trigger mechanism already prepared for the collapse of the massif. So, on the right slope of the river valley. Aktury in Kyrgyzstan after the earthquake in October 1970 formed three extensive landslides. Often, it is not so much the earthquakes themselves that affect buildings and structures, but the landslide and landslide phenomena caused by them (Karategin, 1907, Sarez, 1911, Fayzabad, 1943, Khait, 1949, earthquakes). The mass volume of a seismic landslide (landslide - collapse) located in the Babkha seismic structure (northern slope of the Khamar-Daban ridge, Eastern Siberia) is about 20 million m 3 . The Sarez earthquake of magnitude 9, which occurred in February 1911, threw the river from the right bank. Murgab at the confluence of the Usoy-Darya 2.2 billion m 3 of rock mass, which led to the formation of a dam 600-700 m high, 4 km wide, 6 km long and a lake at an altitude of 3329 m above sea level with a volume of 17-18 km 3 , mirror area 86.5 km 2 , 75 km long, up to 3.4 km wide, 190 m deep. A small village turned out to be under the rubble, and the village of Sarez was under water.

As a result of the seismic impact during the Khait earthquake (Tajikistan, July 10, 1949) with a magnitude of 10 points, landslide and landslide phenomena on the slope of the Takhti ridge were greatly developed, after which earthen avalanches and mudflows of 70 meters thickness were formed at a speed of 30 m / s. The mudflow volume is 140 million m 3 , the destruction area is 1500 km 2 .

Construction in seismic regions (seismic microzoning). During construction work in earthquake areas, it must be remembered that the scores of seismic maps characterize only some average soil conditions of the area and therefore do not reflect the specific geological features of a particular construction site. These points are subject to refinement on the basis of a specific study of the geological and hydrogeological conditions of the construction site (Table 14). This is achieved by increasing the initial scores obtained from the seismic map by one for areas composed of loose rocks, especially wet ones, and decreasing them by one for areas composed of strong rocks. The rocks of category II in terms of seismic properties retain their original intensity unchanged.

Construction site score adjustments are mainly valid for flat or hilly areas. For mountainous areas, other factors need to be taken into account. Dangerous for construction are areas with highly dissected terrain, river banks, slopes of ravines and gorges, landslide and karst areas. Areas located near tectonic ruptures are extremely dangerous. It is very difficult to build with a high groundwater level (1-3 m). It should be taken into account that the greatest destruction during earthquakes occurs in swampy areas, on flooded dusty, on loess undercompacted rocks, which are vigorously compacted during seismic shaking, destroying the buildings and structures built on them.

When conducting engineering and geological surveys in seismic areas, it is required to perform additional work regulated by the relevant section of SNiP 11.02-96 and SP 11.105-97.

In areas where the magnitude of earthquakes does not exceed 7 points, the foundations of buildings and structures are designed without seismicity. In seismic regions, i.e., regions with an estimated seismicity of 7, 8 and 9 points, the design of foundations is carried out in accordance with the chapter of a special SNiP on the design of buildings and structures in seismic regions.

In seismic areas, it is not recommended to lay water conduits, main lines and sewer collectors in water-saturated soils (except for rocky, semi-rocky and coarse-grained soils), in bulk soils, regardless of their moisture content, as well as in areas with tectonic disturbances. If the main source of water supply is groundwater of fissured and karst rocks, surface water bodies should always serve as an additional source.

Of great practical importance for the life and production activities of a person is the prediction of the moment of the beginning of an earthquake and its strength. There have already been noticeable successes in this work, but in general, the problem of earthquake prediction is still at the development stage.

Volcanism- this is the process of magma breakthrough from the depths of the earth's crust to the surface of the earth. Volcanoes - geological formations in the form of mountains and elevations of cone-shaped, oval and other shapes that arose in places where magma burst onto the earth's surface.

Volcanism manifests itself in areas of subduction and obduction, and inside lithospheric plates - in geosyncline zones. The largest number of volcanoes are located along the coasts of Asia and America, on the islands of the Pacific and Indian Oceans. There are also volcanoes on some islands in the Atlantic Ocean (off the coast of America), in Antarctica and Africa, and in Europe (Italy and Iceland). Distinguish between active and extinct volcanoes. Operating name those volcanoes that constantly or periodically erupt; extinct- those that have ceased their action, and there is no data on their eruptions. In some cases, extinct volcanoes resume their activity again. So it was with Vesuvius, an unexpected eruption of which occurred in 79 AD. e.

On the territory of Russia, volcanoes are known in Kamchatka and the Kuril Islands (Fig. 47). There are 129 volcanoes in Kamchatka, 28 of them are active. The most famous volcano is Klyuchevskaya Sopka (altitude 4850 m), the eruption of which is repeated approximately every 7-8 years. Volcanoes Avachinsky, Karymsky, Bezymyansky are active. There are up to 20 volcanoes on the Kuril Islands, of which about half are active.

Extinct volcanoes in the Caucasus - Kazbek, Elbrus, Ararat. Kazbek, for example, was still active at the beginning of the Quaternary period. Its lavas in many places cover the area of ​​the Georgian Military Highway.

Extinct volcanoes have also been discovered in Siberia within the Vitim Highlands. Volcanic eruptions occur in different ways. This largely depends on the type of magma that is being erupted. Acid and medium magmas, being very viscous, give eruptions with explosions, ejection of stones and ash. The outpouring of magma of the main composition usually occurs quietly, without explosions. In Kamchatka and the Kuril Islands, volcanic eruptions begin with tremors, followed by explosions with the release of water vapor and outpouring of red-hot lava.

The eruption, for example, of Klyuchevskaya Sopka in 1944-1945. was accompanied by the formation of a hot cone up to 1500 m high above the crater, the release of hot gases and rock fragments. This was followed by an outpouring of lava. The eruption was accompanied by a magnitude 5 earthquake. During the eruption of volcanoes such as Vesuvius, heavy rainfall is characteristic due to the condensation of water vapor. Mud streams of exceptional strength and grandeur arise, which, rushing down the slopes, bring enormous destruction and devastation. Water formed as a result of melting snow on the volcanic slopes of craters can also act; and the water of the lakes formed on the site of the crater.

The construction of buildings and structures in volcanic areas has certain difficulties. Earthquakes usually do not reach destructive force, but the products released by the volcano can adversely affect the integrity of buildings and structures and their stability. Many gases released during eruptions, such as sulphurous gases, are dangerous to humans. Condensation of water vapor causes catastrophic downpours and mud flows. Lava forms streams, the width and length of which depend on the slope and terrain. There are cases when the length of the lava flow reached 80 km (Iceland), and the thickness was 10–50 m. , sand, lapilli (particles 1-3 cm in diameter), bombs (from centimeters to several meters). All of them are solidified lava and, during a volcanic eruption, scatter to various distances, cover the surface of the earth with a multi-meter layer of debris, and bring down the roofs of buildings.

Every day various areas of our planet are shaken by tremors. An earthquake is one of natural Disasters that cannot be prevented by humans.

The only thing he can oppose to the indomitable forces of nature is the achievements of science in the field of forecasting. Systematization and monitoring of seismic activity makes it possible to avoid human casualties and destruction in time, as well as to identify areas of the greatest seismic activity.

Accounting for earthquake sources

Earth seismic activity map is physical map planet, which displays areas where earthquakes with a power of more than 4 points on the Richter scale occurred over a certain period of time. The following conventions are used on the map: the diameter of the area is proportional to the power of the tremors, and the color of the circle indicates the time interval. For example, red areas correspond to earthquakes occurring on the current date or in real time.

Seismic monitor, updated every 20 minutes


red circles - earthquakes in the last 24 hours
orange circles - earthquakes in the last 1-4 days
yellow circles - earthquakes in the last 4-14 days

EMSC and Google Map data

The map of seismic activity of the world allows you to select a section of the earth's surface by pressing the mouse button. In this case, the selected area will be displayed separately in the window, on which earthquake epicenters are indicated in detail. The online seismic monitor allows you to get comprehensive data when choosing any of the sources. The table shows the coordinates of the epicenters and the power of tremors, ranging from 24 hours to 30 days. Also, on the map of the region, seismic fixation stations located in the selected area are displayed.

List of earthquakes

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Seismic activity map online, updated every 20 minutes. In addition, you can always find out whether there was an earthquake today or not. This allows you to more visually evaluate the information provided.

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Earth seismic activity

The images below are from IRIS, a non-profit organization founded in 1984 with support from the National Science Foundation and a consortium of more than 100 US universities dedicated to the study, organization and distribution of seismological data. IRIS programs are aimed at Scientific research, education, reduction of consequences of earthquakes.

On the data below, the time is UTC (Universal Coordinated Time), to convert to Moscow, add 4 hours.

Seismic activity scale. Richter scale. Earthquake by type of activity.

Current seismic of the Atlantic Ocean

This map shows Pacific Ocean, as well as the eastern regions of Russia - the Far East and the Kuriles. The fault line of the Pacific ridge is clearly visible.


Seismic activity in Russia and Central Asia


Map of seismic activity in Russia and Europe

As you already know, most of the city's residents live in three main types of houses: small-block, large-block, large-panel. Frame-panel buildings are, as a rule, public and administrative. Let's try to imagine an earthquake situation for each of these houses.

So, you are in a small block house. The lack of seismicity of such an unfortified house is 1.5-2 points. We only note that cracks in the internal and external walls can be from hairline to 3-4 centimeter. Cracks of such dimensions, through which the street was visible, were observed by a commission of specialists in similar houses in the city of Leninakan after Spitak earthquake. You should not panic at the sight of such violations, because the house is designed for this. You should be especially careful if the destruction will be very different from those that we have described. For example, there will be a shift of floors from the walls by 3 or more centimeters. rice. 5 What elements of the house best resist the elements?

Let's turn to Figure 5, which shows the most typical layout of a residential 2-5-storey small-block house. Bearing (on which the floors are supported) main walls 1.2 are less damaged than transverse 3.4.5. The latter are easier to move (cut off) by horizontal seismic forces, since they are less loaded. Particularly dangerous is the end wall 4, which is connected to the other walls only on one side. Sometimes the ends of buildings even break away from the building and fall out, which has been repeatedly observed in the village of Gazli, the cities of Spitak and Neftegorsk. The most dangerous corner of the building 6, which is the least connected with the building and is most susceptible to "loosening" during an earthquake. Already with a 7-8 magnitude earthquake, the corners of buildings on the top floor, as a rule, are damaged, and with a magnitude 9 earthquake they can fall out. It is not recommended to be at the outer longitudinal walls (1) during an earthquake, since glass can “shoot out” here, windows fall out in and out (this remark is true not only for small-block houses), and even come off in especially weak houses (longitudinal walls from transverse ). The most secure during an earthquake are the intersections of the internal load-bearing longitudinal walls (2) with internal transverse ones. The figure shows the most typical "safety islands": at the exits from the apartments to the stairwell and at the intersection wall 5. In these places, due to the cross-shaped intersection of load-bearing and non-bearing walls, a core of increased strength is created, which can withstand even when the remaining walls collapse. This core is stronger, the fewer doorways it has. So, for example, the most reliable place will be at the right three-room apartment in the area of ​​​​the intersection of internal walls 2 and 5. Also, the island in the two-room apartment at the intersection of blind sections of walls of type 3 and 2 seems to be reliable. As for the one-room and left three-room apartments, they have cores they have one or two openings and are therefore considered less durable than cores with blank walls. Therefore, if necessary, here you can move along wall 2. In such houses built in the 70-80s. the doorways leading to the staircase are framed with reinforced concrete frames, which guarantees their strength. However, in houses of earlier construction, frames are not everywhere, so these exits cannot be considered completely safe. A few general tips for behavior. As soon as the earthquake starts, you should open the doors leading to the landing and go to the safety island. It is worth trying to run out of the building if you are on the first or second floors. From a higher floor, you may not have time to do this before serious destruction begins. You need to run out of the house especially quickly and carefully so that you are not “covered” by bricks flying from the roof from destroyed pipes, or crushed by a heavy visor. If you did not have time to get to the island of safety, then you should remember that partitions made of small-block masonry are very dangerous. They are among the first to be destroyed, up to the collapse. Wooden shield partitions are less dangerous, but rather large pieces of plaster can fall off from them, which are especially dangerous for young children. It is easy to distinguish a stone partition from a shield one by a deaf, very short, non-vibrating sound when you hit the wall with your fist. When arranging furniture in the apartment, pay attention to the fact that bulky furniture cannot fall into the territory of the island of safety or into the path of a possible evacuation from the apartment.

Many residents of large block houses know that their houses withstand an earthquake quite well. Their real seismic resistance is estimated by experts at 7.7 points.

On fig. 6 shows a typical layout of a large-block house. The position of the capital load-bearing and non-bearing walls is the same as in a small-block house. A large-block house loses its bearing capacity mainly due to the stratification of the walls into separate blocks, which, unfortunately, do not have a good connection with each other in old houses. The outer walls consist of two blocks according to the height of the floor: a wall block with a height of 2.2 m and a lintel with a height of 0.6 m. The internal walls consist of blocks with a floor height, i.e. 2.8 m. on the lintel blocks of the outer walls and directly on the blocks of the inner walls. With an earthquake of more than 7 points, the blocks begin to shift from the plane of the wall. The greatest cracks and destruction of joints (11) should be expected in non-bearing transverse walls less loaded with slabs, especially in the end wall (4) and the walls of the staircase (3). In the last walls there is a small connection of the blocks with each other with the help of not very strong metal plates, which already during an earthquake of 7.5-8 points will begin to loosen greatly, breaking off pieces of concrete and plaster around them. This debris can injure people running up the stairs, so it is necessary to move by clinging closer to the railing. rice. 6. As in small block buildings, the corners of the building (6) are very dangerous, especially on the upper floors. The displacement of blocks from the plane of the wall can lead to partial collapse of the end wall (4) and floor slabs. Partitions in these houses, as a rule, are wooden, panel, plastered, and one should not be afraid of their collapse. Injury, especially to a small child, can be caused by pieces of plaster falling off the partitions and pieces of cement mortar falling out of the joints between the floor slabs. Such damage occurs during an earthquake of 7.5 points. The figure shows the safest places in a large-block house. In contrast to small-block buildings, here all the exit doors to the landing are reinforced with reinforced concrete frames (9), so the probability of door jamming due to skew is low and the exit from the apartment is quite reliable. To the general advice - do not hang heavy shelves in the safety island area and fix furniture, it should be added that this is especially important to do in the storage closet (7) and in the corridor (8), otherwise there will simply be no place for you on the safety island.

In old large-panel five-story residential buildings, the typical layout of which is shown in Fig. 7, the area of ​​safety islands is already much larger. Despite the fact that these houses were designed for 7-8 points, practice has shown that their real seismic resistance is close to 9 points. No such building anywhere during earthquakes on the territory of the former Soviet Union was not destroyed. All external and internal walls in such houses are reinforced concrete large panels, well connected at the nodes using monolithic and welding (node ​​5). Internal walls and partitions are connected to each other on welded outlets. The floor panels are the size of a room, rest on the walls on four sides and are also welded to the walls. It turns out a reliable honeycomb structure. Calculations of the behavior of a large-panel house during a 9-point earthquake showed that the greatest damage is expected in the corners of the building (6), and in the junctions of the end panels (4), where large vertical cracks of 1-2 cm can open up. The first cracks may already appear with L-7.5 points. The same cracks can appear at expansion joints between buildings. But these cracks do not affect the overall stability of the building. Unpleasant factors include the possible appearance of oblique cracks up to 1 cm wide in reinforced concrete lintels above the entrance doors to apartments, which can lead to door jamming. Therefore, they must be closed immediately at the beginning of oscillations with a force of 6 points or more. Since large-panel buildings are quite reliable, you should not run out of them during an earthquake. But it is recommended to stay during an earthquake in the zone of safety islands, away from the outer walls, where window panes can “shoot out”, and from the end wall, in the nodes of which extended frightening cracks can open. You should not run out also because in the old houses of this series there are very heavy dangerous peaks over the entrances to the entrances. Embedded metal parts with which these visors were attached to the building. due to aging, they are heavily rusted and may not hold them in case of strong seismic shocks.

During an earthquake on In Shikotan, in 1994, several canopies fell near similar large-panel three-story houses, which crushed two residents who ran out of one house. However, not a single person who remained in the house was injured. The house itself was not seriously damaged. Later large-panel houses, the so-called "improved" series, with bay windows, as well as houses of a "new" layout with large glazed balconies, were originally designed for 9 points and it is practically safe to be in them during an earthquake of this magnitude. You need to beware of broken glass falling from above, especially from balconies, which can scatter on long distances- up to 15 meters. Therefore, it is not recommended to run out of these houses, just as it is not recommended to be on the street next to them. Fig.7 Experience shows that even with strong 8-9 magnitude earthquakes, 1-2-storey wooden houses practically do not collapse before a collapse. One of the authors of the book, observed the behavior of panel and block houses during a 9-point earthquake on about. Shikotan. Of the almost fifty two-story houses surveyed, there was not a single house where at least one wall collapsed or the ceiling failed. There were cases when the foundation "pulled out" from under the house and was carried away by a landslide by 1-1.5 meters, and the house, bowed, stood! There were wall breaks in the corners up to 20 cm and subsidence of the soil under the building up to 0.5 m, but the houses survived. Therefore, one should not run out of such houses anywhere, especially since the danger is represented by bricks falling on running out from collapsing chimneys. IN wooden houses floors sway more strongly than others and walls “crack”, which causes discomfort. Pieces of plaster can fall out of the walls and from the ceiling. Therefore, in such houses it makes sense to choose a place where the plaster fits snugly against the wall, ceiling, i.e., it “does not coil” in advance when tapped. Children are better off hiding under the table. And, of course, you need to stay away from the outer walls with windows, from heavy cabinets and shelves, especially if they are not specifically fixed. This is general rule for any building.

Home training. Let's do a thought experiment. Close your eyes and imagine that you are lying on your own bed. Imagine that at this moment the first strong seismic shock has occurred. Now mentally try to get to the door as quickly as possible, open it and take a place in the doorway. At the same time, bend your fingers on your hand in each case when, in your mental progress, you come across obstacles that really exist. Now count. Each obstacle is at least 3 lost seconds. Estimate net movement time and door lock opening time. Add seconds to grab a backpack with documents and products (no doubt, it hangs next to the door, as recommended). And if you get more than 20 seconds, then give yourself a fat FAILURE, and let's get down to reorganization. Make a list of obstacles found during the experiment. This is the minimum to be done. Let's start moving in reverse order. Evaluate the door lock in terms of the ability to quickly open the door. Is it easy for you to find the lock itself and its opening device even in the dark? How many actions are required to unlock the lock and the door? Try to arrange everything in such a way that the lock opens with a minimum of movements, and bring these movements to automatism .. Inspect the space near the front door. Are there objects nearby that, at the first push, can fall and block your path? If there are any, either strengthen them, or determine a more suitable place for them in the apartment. The corridor should be as free as possible. Very often, the passage is cluttered with things that have only recently been brought into the apartment and have not yet found their permanent place. Everyone knows that there is nothing more permanent than temporary. Therefore, without postponing "for later", clear your way to salvation. Pay attention to the fact that there are no objects along the walls that you can catch on. Look under your feet to see if shoes that are not currently in use have been removed from the corridor and if they create obstacles for movement. Now let's pay attention to the door from the corridor to the room. It is desirable that it be constantly open. Think about how you can fix it in the open position, and equip the latch. If there is carpet on the floor or there are tracks, then check how tightly they fit to the floor, if there are any gathers, folds, scuffs. Does the track slip on the main floor covering? Pay special attention to the joints of carpets and paths. Eliminate all flaws, let the path be "silk". IN last years mobile interior elements have firmly entered our everyday life: tables on wheels, mobile cabinets for TV, video and audio equipment. Make it a rule not to leave them in the evening on a possible escape route. Leave them in such a position that their spontaneous movement in the event of seismic shocks cannot occur in the direction of this escape route and does not cause objects or furniture to fall along this route. If you use extension cords to connect electrical equipment, then make sure that the wires do not cross the path of your movement to the exit. The pride of almost every family is the home library. Check for books on open shelves, from which, at the first seismic shock, they can fall under your feet or fall on your head when you run to the door. Evaluate from the same positions objects standing on open shelves, especially if these shelves are above the doors. Make sure the shelves themselves are securely fastened. Bedside tables should also be securely fastened so as not to be the first insurmountable barrier to salvation. It is advisable to fix the table lamps standing on these cabinets. If the drawers in these bedside tables easily fall out or open with slight pressure on the door, then make sure that they are securely fixed. Clothing periodically accumulating next to the bed can be a serious obstacle to fast movement. Make it a rule to put things away that you won't be wearing that day. (It turns out that a possible strong earthquake is an important reason to keep the house in order!)

Recall the thought experiment you did again and note which obstacle came first in your path. If it is resolved, then check if there are any unresolved barriers in your post-experimental list and take appropriate measures. Check now the exit path for each family member. If there are small children in the family and you will first move towards them, then pay attention to those sections that you will have to cross twice in different directions. Find out if you will create obstacles for the way back with your first movement. Similarly, inspect and tidy up the escape route from the living room and kitchen. Please note that several people, including children, can move from these rooms at the same time. When you watch athletics competitions, then, watching a steeplechase race, you often have a desire to make the path easier for athletes and remove obstacles and a hole with water. How easily and beautifully they would have reached the finish line. But the rules of the game don't allow it. The rules of seismic safety, on the contrary, tell us - do not bring things to a home steeplechase, otherwise you will not be able to safely reach the finish line. Therefore, we advise you to remove barriers from the road and not take unnecessary risks.

An excerpt from the work of V.N. Andreeva, V.N. Medvedev "PROBLEMS OF SEISMIC RISK IN THE REPUBLIC OF SAKHA (YAKUTIA)" without author's illustrations.

Killer houses on the disaster map

An alarming trend was revealed by the latest maps of the general seismic zoning of the territory Russian Federation: compared with previous calculations, the number of regions with increased seismic hazard has increased significantly.

The planet continues to show its violent nature. Earthquakes occur with surprising regularity. In just two weeks there were 15 of them - in Turkey and Mexico, Sakhalin and Kamchatka, Los Angeles and Alaska, the Caucasus and Taiwan, the Ionian Sea and Japan. Fortunately, this time the tremors were not the strongest - their maximum intensity did not exceed 6.2 points, but they also led to destruction and death. But a strong earthquake can become an economic and social catastrophe for the whole country, just remember the tragedy in India on January 26 last year.
IN recent decades the danger of seismic disasters has increased dramatically, which is primarily due to economic activity man, man-made impacts on the earth's crust - the creation of reservoirs, the extraction of oil, gas, solid minerals, the injection of liquid industrial waste and a number of other factors. And the possible destruction of large engineering structures built on the surface (nuclear power plants, chemical plants, high-rise dams, etc.) can lead to environmental disasters. An example of such a potential hazard is the Balakovo NPP, which will withstand an earthquake no stronger than 6 points, despite the fact that the Saratov region today is classified as a seven-point seismicity zone.
Practically not a single strong tremor passes without a trace: after each, the expected seismic hazard in the affected and adjacent regions increases. For example, the earthquake in Neftegorsk in 1995 was estimated by experts as 9-10 points. But back in the 60s, this and the adjacent territories were not considered seismically dangerous at all, and the possibility of earthquakes was not taken into account when designing buildings. The same underestimated seismic activity forecasts were made in Japan, China, Greece and other countries. Unfortunately, similar errors are not ruled out in the future.
So the sad list of regions where the earth can suddenly stand on end is constantly growing. The latest Maps of the general seismic zoning of the territory of the Russian Federation clearly demonstrate this. Until recently, two regions of Russia were considered the most seismic - Sakhalin, Kamchatka, the Kuriles and other regions of the Far East, as well as the territories of Eastern Siberia adjacent to the Baikal and Transbaikalia, including the Altai Mountains. Catastrophic earthquakes with an intensity of 9 or more points (up to 8.5 on the Richter scale) are possible there. By the way, the territory of the Sakhalin region is one of the most seismically dangerous not only in Russia, but also in the world.
Now, on the latest maps, the threat of earthquakes of magnitude 9 or more has spread to a significant part of the North Caucasus, where about 7 million people live. And this despite the fact that the construction of residential buildings and industrial buildings until recently was carried out here, taking into account the seismicity of 7 points. The Krasnodar Territory with a population of five million causes the greatest concern. In the summer months, on a narrow strip of the Black Sea coast, the number of people increases many times over.
Another very important difference between the new maps is that for the first time zones of 10-magnitude earthquakes appeared on them. They are located on Sakhalin, Kamchatka and Altai. Previously, there were no such areas in our country.
But the exact location, strength and time of an earthquake cannot be predicted. There are no ways to prevent the cataclysm. The main task is to minimize the destruction and loss of life. The latest strong earthquakes in Neftegorsk (1995), Turkey and Taiwan (1999) showed that fundamentally new approaches are needed in the regulation and design of engineering structures.

In the meantime, experts come to shocking results: the main "killers" of people during earthquakes are buildings of two types. And the most common. First of all - houses with walls made of low-strength materials. The second type is reinforced concrete frame buildings, the mass destruction of which turned out to be completely unexpected, since until recently they were in one of the first places in terms of seismic resistance. So, during the earthquake in Leninakan, 98 percent of the reinforced concrete frame houses folded like an accordion, more than 10 thousand people died in them.

Unlike frame buildings, large-panel buildings and houses with walls made of monolithic reinforced concrete, which have maximum rigidity in all directions, have proven themselves very well.
Of course, the cardinal solution to the current situation: the demolition of all dangerous houses and the construction of new ones in their place is unrealistic today. Therefore, the most difficult and urgent task is to strengthen buildings built without taking into account possible seismic effects or designed for minor earthquakes. Unfortunately, in Russia this problem is extremely acute. It is not for nothing that the Federal Target Program “Seismic Safety of the Territory of Russia”, which began operating this year, contains a terrible phrase: “In the entire history of the USSR and the Russian Federation, nationwide programs on seismic safety have not been implemented in the country, as a result of which tens of millions of people live in seismically hazardous territories. in houses characterized by a seismic resistance deficit of 2-3 points. At the same time, in a number of constituent entities of the Russian Federation, even according to rough estimates, from 60 to 90 percent of buildings and other structures should be classified as non-seismic.
According to the Program, more than half of the territory of Russia may be affected by earthquakes of medium magnitude, which can lead to severe consequences in densely populated areas, and “about 25 percent of the territory of the Russian Federation with a population of more than 20 million people may be subject to earthquakes of magnitude 7 or more.
Taking into account the high seismic hazard, population density, the degree of actual seismic vulnerability of development, the subjects of the Russian Federation were classified depending on the seismic risk index and divided into 2 groups.
The first group (see table) included 11 constituent entities of the Russian Federation, the regions with the highest seismic risk. Many cities and large settlements in these regions are located in areas with seismicity of 9 and 10 points.
The second group includes Altai, Krasnoyarsk, Primorsky, Stavropol and Khabarovsk Territories, Amur, Kemerovo, Magadan, Chita Regions, Jewish Autonomous Region, Ust-Ordynsky Buryat, Chukotsky and Koryaksky autonomous regions, the republics of Sakha (Yakutia), Adygea, Khakassia, Altai and Chechen Republic. In these regions, the predicted seismic activity is 7-8 points and lower.
Moscow and the Moscow region, according to the Russian Academy of Sciences, are not a seismically hazardous area. The maximum possible fluctuations here will not exceed 5 points.

Alexander Kolotilkin

High risk area

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*Seismic risk index characterizes the required amount of anti-seismic reinforcement, takes into account seismic hazard, seismic risk and population in large settlements.