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Natural phenomena and their classification. Natural phenomena occurring on the territory of Russia

Nature is not always as serene and beautiful as in the photo above these lines. Sometimes she shows us her dangerous manifestations. From violent volcanic eruptions to terrifying hurricanes, nature's fury is best seen from afar and from a distance. We often underestimate the amazing and destructive power of nature, and she reminds us of this from time to time. While all this looks spectacular in photographs, the consequences of such phenomena can be very scary. We must respect the authority of the planet we live on. For you, we have made this photo and video selection of frightening natural phenomena.

TORNADO AND OTHER TYPES OF TONNADO

All these types of atmospheric phenomena are dangerous vortex manifestations of the elements.

Tornado or tornado arises in a thundercloud and spreads down, often to the very surface of the earth, in the form of a cloud sleeve or trunk with a diameter of tens and hundreds of meters. Tornadoes can appear in many shapes and sizes. Most tornadoes appear as a narrow funnel (only a few hundred meters across), with a small cloud of debris near earth's surface. A tornado can be completely hidden by a wall of rain or dust. Such tornadoes are especially dangerous, as even experienced meteorologists may not recognize them.

Lightning tornado:


Tornado in Oklahoma, USA (May site 2010):

Supercell Thunderstorm in Montana, USA, formed by a huge rotating thundercloud 10-15 km high and d about 50 km in diameter. Such a thunderstorm creates tornadoes, heavy winds, large hail:

Thunderclouds:

View of a hurricane tornado from space:

There are other, outwardly similar, but different in nature vortex phenomena:

It is formed as a result of the rise of warmer air from the surface of the earth. Tornado-vortices, unlike tornadoes, develop from the bottom up, and the cloud above them, if formed, is a consequence of the vortex, and not its cause.

Dusty (sandy) whirlwind- this is a vortex movement of air that occurs near the surface of the earth during the day in slightly cloudy and usually hot weather when the earth's surface is strongly warmed by the sun's rays. The vortex lifts dust, sand, pebbles, small objects from the surface of the earth and sometimes transfers them to a site at a considerable distance (hundreds of meters). Whirlwinds pass in a narrow strip, so that in case of weak wind its speed inside the whirlwind reaches 8-10 m/s and more.

Sandstorm:

Or a firestorm is formed when a column of hot, rising air interacts with or causes a fire on the ground. It is a vertical whirlpool of fire in the air. The air above it heats up, its density decreases, and it rises. From below, cold air masses from the periphery enter in its place, which immediately heat up. Steady streams are formed, screwing in a spiral from the ground to a height of up to 5 km. There is a chimney effect. The pressure of hot air reaches hurricane speeds. The temperature rises to 1000˚С. Everything burns or melts. At the same time, everything that is nearby is “sucked” into the fire. And so on until everything that can burn is burned.

The site is a funnel-shaped air-water vortex, similar in nature to an ordinary tornado, which forms above the surface of a large reservoir and is connected to a cumulus cloud. A water tornado can form when a normal tornado passes over a water surface. Unlike a classic tornado, a water tornado exists for only 15-30 minutes, is much smaller in diameter, the speed of movement and rotation is two to three times lower, and is not always accompanied by a hurricane wind.

DUST OR SAND STORMS

Sand (dust) storm- it's dangerous atmospheric phenomenon, which manifests itself in the form of wind a large number particles of soil, dust or fine grains of sand from the surface of the Earth. The height of the layer of such dust can be several meters, and horizontal visibility is noticeably worse. For example, at a level of 2 meters, visibility is 1-8 kilometers, but often visibility in a storm is reduced to several hundred or even tens of meters. dust storms The site occurs mainly when the soil surface is dry and the wind speed is more than 10 meters per second.

The fact that a storm is approaching can be understood in advance by the incredible silence that forms around, as if you suddenly fell into a vacuum. This silence is depressing, creating an inexplicable anxiety within you.

Sandstorm on the streets of the city of Onslow in the northwest of Australia, January 2013:

Sandstorm in Golmud Village, Qinghai Province, China, 2010:

Red sandstorm in Australia:

TSUNAMI

is a dangerous natural disaster, which is sea waves resulting from a shift seabed during underwater and coastal earthquakes. Having formed in any place, a tsunami can spread from high speed(up to 1000 km / h) for several thousand kilometers, while the height of the tsunami is initially from 0.1 to 5 meters. When reaching shallow water, the wave height increases sharply, reaching a height of 10 to 50 meters. Huge masses of water thrown ashore lead to flooding and destruction of the area, as well as to the death of people and animals. An air shock wave propagates in front of the water shaft. It acts similarly to a blast wave, destroying buildings and structures. The tsunami wave may not be the only one. Very often it is a series of waves rolling ashore with an interval of 1 hour or more.

Tsunami in Thailand caused by an earthquake (9.3 points) in Indian Ocean December 26, 2004:

CATASTROPHIC FLOODS

Flood- flooding of the territory with water, which is a natural disaster. Floods happen different types and due to various reasons. Catastrophic floods lead to death of people, irreparable environmental damage, cause material damage, covering vast territories within one or more water systems. At the same time, the economic site is completely paralyzed and production activity, temporarily changes lifestyle population. The evacuation of hundreds of thousands of people, the inevitable humanitarian catastrophe requires the participation of the entire world community, the problem of one country becomes the problem of the whole world.

Flooding in Khabarovsk and the Khabarovsk Territory, caused by intense showers that covered the entire Amur River basin and lasted about two months (2013):

New Orleans flooding after a hurricane. New Orleans (USA) stands on damp ground, which is not able to support the city. Orleans sinks slowly into the ground, and the Gulf of Mexico gradually rises around it. Most of New Orleans is already 1.5 to 3 meters below sea level. This was greatly facilitated by Hurricane Katrina in 2005:

Flooding in Germany, in the Rhine river basin (2013):

Flood in Iowa, USA (2008):

THUNDER LIGHTNING

Lightning discharges (lightning) are a giant electrical spark discharge into the atmosphere, with a very long spark, usually occurs during a thunderstorm, manifested by a bright flash of light and accompanying thunder. The total length of the lightning channel reaches several kilometers (2.5 km on average), and a significant part of this channel is located inside the thundercloud. Some discharges extend in the atmosphere for a distance of up to 20 km. The current in a lightning discharge reaches 10-20 thousand amperes, so not all people survive after a lightning strike.

forest fire- this is a spontaneous, uncontrolled spread of fire in forest areas. The causes of fires in the forest can be natural (lightning, drought, etc.) and artificial, when people are the cause. Forest fires come in several forms.

Underground (soil) fires in the forest are most often associated with the ignition of peat, which becomes possible as a result of the drainage of swamps. They can be hardly noticeable and spread to a depth of several meters, as a result of which they represent an additional danger and are extremely difficult to extinguish. Like, for example, a peat fire in the Moscow region (2011):

At ground fire the forest floor, lichens, mosses, grasses, branches that have fallen to the ground, etc., burn down.

Riding forest fire covers leaves, needles, branches and the entire crown; it can cover (in the event of a general fire) the grass-moss cover of the soil and undergrowth. They usually develop in dry windy weather from a ground fire, in plantations with low crowns, in plantations of different ages, as well as in abundant coniferous undergrowth. This is usually the final stage of a fire.

VOLCANOES

Volcanoes- These are geological formations on the surface of the earth's crust, most often in the form of a mountain, where magma comes to the surface, forming lava, volcanic gases, stones and pyroclastic flows. When molten magma pours through cracks in the earth's crust, a volcano erupts, the site of the Roman god of fire and blacksmithing.

Karymsky volcano is one of the most active volcanoes in Kamchatka:

Underwater volcano - the coast of the Tonga archipelago (2009):

Underwater volcano and subsequent tsunami:

Volcanic eruption photographed from space:

Volcano Klyuchevskoy in Kamchatka (1994):

The eruption of Mount Sinabung in Sumatra was accompanied by several mini-tornadoes:

Puyehue volcano eruption in Chile:

Lightning in the ash cloud of the Chaiten volcano in Chile:

Volcanic Lightning:

EARTHQUAKE

Earthquake- these are tremors and vibrations of the Earth's surface caused by natural tectonic processes (movement of the earth's crust and displacements and ruptures occurring in it) or artificial processes (explosions, filling of reservoirs, collapse of underground cavities of mine workings). May cause volcanic eruptions and tsunamis.

Japan earthquake followed by tsunami (2011):

LANDSLIDE

Landslide- a detached mass of loose rocks, slowly and site gradually or abruptly creeping along an inclined plane of separation, while often retaining its coherence, solidity and not overturning its soil.

SEL

sel- a stream with a very high concentration of mineral particles, stones and rock fragments (something between a liquid and a solid mass), which suddenly appears in basins of small mountain rivers and caused, as a rule, by heavy rainfall or rapid snowmelt.

SNOW AVALANCHES

snow avalanches belong to landslides. This is a mass of snow falling or sliding off the slopes of mountains.

This is one of record avalanches size 600 thousand cubic meters. The film crew was not harmed.

“This is the consequence of the avalanche - snow dust, it flew high, and everything disappeared as if in a fog. Everyone was doused with snow dust, which, by inertia, continued to move at the speed of a snowstorm. It became dark as night. Because of fine-fine snow the site was hard to breathe. Hands and feet instantly stiffened. I didn't see anyone around. Although there were people nearby, ”said Anton Voitsekhovsky, a member of the film crew.

To natural hazards include natural phenomena that pose a threat to human life and health.

All natural hazards are subject to the following patterns:

      each type of hazard is characterized by a certain spatial confinement;

      the greater the intensity (power) of a dangerous phenomenon, the less often it happens;

      each type of danger is preceded by certain specific signs (harbingers);

      the manifestation of any natural hazard can be predicted;

      in most cases, passive and active protective measures can be provided.

The manifestation of natural hazards is significantly influenced by anthropogenic impact: according to international statistics, the origin of about 80% of modern landslides is associated with human activities; as a result of deforestation, the activity of mudflows increases, the flood flow increases; large-scale use of natural resources has led to tangible manifestations of the global environmental crisis.

The study of the causes and mechanisms of natural hazards makes it possible to predict them, which is the most important prerequisite for effective protection. Protection from natural hazards can be active (construction of engineering structures, intervention (Latin interventionio - intervention) in the mechanism of the phenomenon, mobilization of natural resources, reconstruction of natural objects, etc.) and passive (use of shelters, evacuation). In most cases, active and passive methods are combined.

By localization, natural hazards are conditionally divided into 4 groups: lithospheric (earthquakes, volcanoes, landslides), hydrospheric (floods, tsunamis, storms), atmospheric (hurricanes, storms, tornadoes, hail), space (asteroids, planets, radiation, magnetic storms) .

1. Lithospheric hazards

Earthquakes. The upper mantle together with the earth's crust form the lithosphere. It is in the mantle (temperature 2000-2500 ° C) that tectonic (from the Greek tektonikos - related to construction) processes occur that cause earthquakes.

earthquakes- these are tremors and vibrations of the earth's surface, resulting from sudden displacements and ruptures in the earth's crust or the upper part of the mantle and transmitted over long distances in the form of elastic vibrations. Earthquakes occur as a series of shocks that include foreshocks, mainshocks, and aftershocks. The main shock is characterized by the greatest force, its duration, as a rule, is several seconds. According to psychiatrists and psychologists, people under the influence of aftershocks, shackled by fear, do nothing instead of looking for a safe place and defending themselves.

The source of an earthquake is a certain volume in the thickness of the Earth, within which energy is released. The center of the focus is a conditional point called hypocenter. The projection of the hypocenter onto the Earth's surface is called epicenter. Around him there is the greatest destruction. Every year, hundreds of thousands of earthquakes are recorded on the globe, most of which are weak and people do not notice them. The strength of an earthquake is estimated by:

      on the scale of intensity, which characterizes the scale of destruction on the surface of the Earth;

      on the magnitude scale, which is the energy characteristic of an earthquake.

The international intensity scale MSK-64, adopted in Russia, is calculated using a 12-point system.

International Earthquake Intensity Scale

Strength in points

Intensity

Consequences

Imperceptible ground shaking

Recorded only by seismic instruments

Very weak

Felt by individuals at rest

Felt by only a small part of the population

Moderate

Light rattling of glass, creaking of doors, walls

Pretty strong

Shaking of buildings, vibrations of equipment, cracks in window panes and plaster

Partial collapse of internal walls, breaks in wire communications, failures in the operation of sensitive equipment, the occurrence of individual fires

Very strong

Damage, cracks in stone buildings and structures, breaks in power lines. Wooden and anti-seismic buildings are preserved

destructive

Cracks on steep slopes and damp soils. Loose equipment shifts and is damaged. Old buildings are destroyed, the rest are badly damaged. The fall of individual power transmission towers, communication lines, ground overpasses

devastating

Strong destruction of stone buildings and structures. Curvature of wooden buildings. Partial damage to hydraulic structures

Destroying

Strong destruction of all buildings and structures. Cracks in the soil up to one meter wide are possible. Destruction of transport routes. Slopes, landslides

catastrophic

Complete destruction of buildings and structures, bending and twisting of railway rails. Widespread cracks on the surface of the earth, landslides and landslides. Underground collapses

Absolute or strong catastrophic

Solid landslides, collapses, huge cracks on the surface of the earth. Deviations and changes in the flow of rivers, the formation of lakes, waterfalls. Partial change in terrain

Richter scale- magnitude scale, based on the assessment of the energy of seismic waves that occur during earthquakes and are recorded by seismographs. The magnitude of earthquakes on the Richter scale cannot exceed 9.5. Magnitude earthquakes - a conditional value that characterizes the total energy of elastic vibrations caused by an earthquake

When an earthquake occurs, its magnitude first becomes known, which is determined by seismograms, and the intensity is determined some time later, after receiving information about the consequences.

Magnitude

Intensity

Magnitude

Intensity
Relationship between magnitude and intensity of earthquakes

According to statistics, an earthquake with a magnitude of 8 occurs every 102 years.

Earthquakes are distributed over the earth's surface very unevenly. The analysis of seismic and geographic data makes it possible to outline the areas where an earthquake should be expected. This is the essence of seismic zoning. Seismic zoning map- this official document which design organizations should be guided by.

Earthquakes are considered dangerous for buildings and structures, the intensity of which is 7 points or more. The strongest earthquake of the twentieth century. occurred on July 28, 1976 near the city of Tangshan in China. According to some data, 242 thousand people died, according to others - more than half a million, the damage amounted to more than $ 2 billion.

There are two groups of anti-seismic measures: 1) preventive, preventive measures carried out before a possible earthquake; 2) activities carried out during and after the earthquake, that is, actions in emergency situations.

The first group includes the study of the nature of earthquakes, the disclosure of its mechanism, the identification of precursors. The harbingers of earthquakes can be the following anomalous phenomena: the disappearance of constant weak earthquakes; changes in the electrical and magnetic properties of rocks; drop in the level of groundwater, a decrease in their temperature and a change in the chemical composition, the release of methane from the earth's crust.

The effectiveness of actions in earthquake conditions depends on the level of organization of emergency rescue operations, the effectiveness of the warning system and the level of education of the population.

At the first shock of an earthquake, it is necessary to urgently leave the building (there are 10-15 seconds left) or take the safest place inside the building: under the doorway, in the openings of the main internal walls or in the corners of these walls.

Volcanic eruptions.Volcanoes are geological formations on the surface of the earth's crust, where magma comes to the surface, forming lava, volcanic gases and stones. These products of the eruption are ejected to a height of 1 to 5 km and are transported over long distances. Magma (from the Greek. magma- thick ointment) is a molten mass of predominantly silicate composition, formed in the deep zones of the Earth.

Volcanoes are divided into active, dormant and extinct.

TO sleeping Volcanoes are those whose eruptions are not known, but they have retained their shape and local earthquakes occur under them.

Extinct are volcanoes without any volcanic activity.

In Russia, Kamchatka, the Kuril Islands, and Sakhalin Island are exposed to the danger of volcanic eruptions. The basis of the eruption forecast is seismic tremors that characterize the beginning of the eruption.

The main dangers are lava fountains, hot lava flows, hot gases. Volcanic explosions can also initiate landslides, collapses, avalanches, and tsunamis on the seas and oceans. Formed during the Krakatoa eruption in 1883 sea ​​wave a height of about 20 m covered those around the island, which led to the death of 36 thousand people.

The most reliable way to protect yourself from a volcanic eruption is to choose a place of residence at the maximum distance from active volcanoes.

Snow avalanches. Avalanche- this is a snowfall, a mass of snow falling or sliding from the mountain slopes under the influence of some kind of influence and entraining new masses of snow on its way.

The danger of an avalanche lies in the high kinetic energy of the avalanche mass, which has tremendous destructive power. Avalanches form on treeless slopes with a steepness of 15° or more. The optimal conditions for the formation of avalanches occur on slopes of 30...40°. With a steepness of more than 50°, the snow crumbles to the foot of the slope, and avalanches do not have time to form. Avalanche speed can reach 125 m/s, averaging 20-60 m/s. It is not possible to accurately predict the timing of an avalanche.

Anti-avalanche preventive measures are divided into 2 groups: passive and active.

Passive Methods consist in the use of supporting structures, dams, avalanche cutters, snow shields, planting and reforestation.

Active Methods consist in artificially provoking an avalanche. For this, directional explosions are organized, strong sound sources are used.

A geological hazard is an event that occurs as a result of the activity geological processes arising in the earth's crust under the influence of various geological or natural factors or their combination, and providing negative impact on plants, people, animals, the natural environment, objects of the economy. Most often, geological phenomena are associated with the movement of lithospheric plates and changes occurring in the lithosphere.

Types of hazardous phenomena

to geological hazards include the following:

  • talus and landslides;
  • sat down;
  • subsidence or dips of the earth's surface as a result of karst;
  • kurums;
  • erosion, abrasion;
  • avalanches;
  • flushes;
  • landslides.

Each species has its own characteristics.

Landslides

Landslides are a geological hazard, which is a sliding displacement of rock masses along slopes under the influence of own weight. This phenomenon occurs as a result of erosion of the slope, due to seismic tremors, or under other circumstances.

Landslides occur on the slopes of hills and mountains, on steep river banks. They can be caused by a variety of natural phenomena:

  • earthquakes;
  • heavy rainfall;
  • uncontrolled plowing of slopes;
  • trimming slopes when laying roads;
  • as a result of deforestation;
  • during blasting;
  • with abrasion and river erosion, etc.

Causes of landslides

Landslides are a dangerous geological phenomenon that most often occurs as a result of the impact of water. It seeps into cracks in the ground rocks, which causes destruction. All loose deposits are saturated with moisture: the resulting layer plays the role of a lubricant between the layers earthen rocks. At breaks inner layers the detached mass begins, as it were, to float down the slope.

Landslide classification

There are several types of dangerous geological phenomena, divided by the speed of movement:

  1. Very fast. They are characterized by the movement of masses at a speed of 0.3 m/min.
  2. Fast are characterized by the movement of masses at a speed of 1.5 m / day.
  3. Moderate - the landslide occurs at a speed of up to one and a half meters per month.
  4. Slow - the speed of movement - up to one and a half meters per year.
  5. Very slow - 0.06 m/year.

In addition to the speed of movement, all landslides are divided by size. According to this criterion, this phenomenon is divided as follows:

  • grandiose, occupying an area of ​​​​more than four hundred hectares;
  • very large - the area of ​​the landslide is about two hundred hectares;
  • large - area - about a hundred hectares;
  • small - 50 ha;
  • very small - less than five hectares.

The thickness of a landslide is characterized by the volume of shifting rocks. This figure can reach several million cubic meters.

Mudflows

Another dangerous geological phenomenon is a mudflow, or mudflow. This is a temporary rapid mountain stream of water mixed with clay, sand, stones, etc. A mudflow is characterized by a sharp rise in the water level, which occurs in wave movements. Moreover, this phenomenon does not last long - for a couple of hours, but has a strong destructive effect. The area affected by a mudflow is called a mudflow basin.

For this dangerous geological natural phenomenon to occur, three conditions must be met simultaneously. Firstly, there should be a lot of sand, clay and stones of small diameter on the slopes. Secondly, to wash it all off the slope, you need a lot of water. Thirdly, mudflow can occur only on steep slopes, with an inclination angle of about twelve degrees.

Causes of mudflows

The occurrence of a dangerous mudflow can occur different reasons. Most often, this phenomenon is observed as a result of intense rains, rapid melting of glaciers, as well as as a result of tremors and volcanic activity.

Mudflow can occur as a result of human activities. An example of this is deforestation on the slopes of mountains, quarrying or mass construction.

snow avalanche

The snow avalanche also belongs to dangerous geological natural phenomena. During an avalanche, a mass of snow slides off the steep slopes of the mountains. Its speed can reach one hundred meters per second.

During the fall of an avalanche, an air pre-avalanche wave is formed, causing big damage nature and any objects erected on the path of the phenomenon.

Why is there an avalanche

There are several reasons why an avalanche begins. These include:

  • intensive snow melting;
  • long snowfall, resulting in a large snow mass that is not able to stay on the slopes;
  • earthquakes.

An avalanche can occur due to strong noises. This phenomenon is provoked by fluctuations in the air environment resulting from sounds emitted at a certain frequency and with a certain force.

As a result of an avalanche, buildings and engineering structures are destroyed. Any obstacles in its path are destroyed: bridges, power lines, oil pipelines, roads. This phenomenon causes great damage agriculture. If there are people in the mountains when the snow melts, they may die.

Snow avalanches in Russia

Knowing the geography of Russia, you can accurately determine where the most dangerous avalanche areas are. The most dangerous areas are mountains with a lot of snowfall. This is Western and Eastern Siberia, Far East, Ural, as well as the North Caucasus and the mountains of the Kola Peninsula.

Avalanches account for about half of all accidents in the mountains. by the most dangerous periods The years are winter and spring. During these periods, up to 90% of snow masses are recorded. An avalanche can descend at any time of the day, but most often it snows during the day, and rarely in the evening. The impact force of the snow mass can be estimated at tens of tons per square meter! While driving, the snow sweeps away everything in its path. If a person fills up, then he will not be able to breathe, as the snow clogs Airways, penetrating the dust into the lungs. People can freeze, get severe injuries, frostbite internal organs.

collapses

And what other phenomena are related to geological hazards and what are they? These include crashes. These are detachments of large masses of rocks on river valleys, the coast of the seas. Collapses occur due to the detachment of masses from the parent base. Landslides can block or destroy roads, causing large amounts of water to overflow from reservoirs.

Falls are small, medium and large. The latter include detachments of rocks weighing from ten million cubic meters. Medium-sized fragments include fragments with a volume of one hundred thousand to ten million cubic meters. The mass of small collapses reaches tens of cubic meters.

Landslides can occur as a result of the peculiarities of the geological structure of the area, as well as cracks on the slopes of mountains. The cause of the formation of landslides can be human activities. This phenomenon is observed during the crushing of rocks, and also due to the large amount of moisture.

As a rule, collapses occur suddenly. Initially on rock a crack is formed. Gradually, it increases, causing separation of the rock from maternal education.

earthquakes

When asked: "Indicate dangerous geological phenomena," the first thing that comes to mind is earthquakes. It is this species that is considered one of the most terrible, destructive manifestations of nature.

To understand the causes of this phenomenon, it is necessary to know the structure of the Earth. As you know, it has a hard shell - the earth's crust, or lithosphere, mantle and core. The lithosphere is not a whole formation, but several huge plates, as if floating on the mantle. These plates move, collide, overlap each other. Earthquakes occur in the zones of their interaction. However, shocks can appear not only along the edges of the plates, but also in their central part. Other reasons due to which shocks occur include volcanic eruptions, man-made factors. In some regions, seismic activity is clearly visible due to water fluctuations in the reservoir.

Earthquakes can result in landslides, subsidence, tsunamis, snow avalanches and much more. One of the dangerous manifestations is soil liquefaction. With this phenomenon, the earth is oversaturated with water, and with shocks lasting ten seconds or more, the soil becomes liquid and loses its bearing capacity. As a result of this, roads are destroyed, houses sag and collapse. One of the clearest examples of this phenomenon is the liquefaction of soil in 1964 in Japan. As a result of this event, several high-rise buildings slowly tilted. They didn't have any damage.

Another manifestation of tremors can be ground subsidence. This phenomenon occurs due to particle vibration.

Serious consequences of earthquakes can be ruptures of dams, as well as the occurrence of floods, tsunamis and more.

Natural hazards include all those that deviate the state natural environment from the range that is optimal for human life and for their economy. They represent catastrophic processes of endogenous and exogenous origin: earthquakes, volcanic eruptions, floods, avalanches and mudflows, as well as landslides, soil subsidence.

In terms of the size of the one-time damage of the impact, hazardous natural phenomena vary from minor to those that create natural disasters.

A natural disaster is any unavoidable terribly destructive natural phenomenon that causes economic damage and poses a threat to the health and life of people. When we are talking about the measurement of losses, use the term - emergency (ES). In emergencies, first of all, absolute losses are measured - for a quick response, to decide on the necessary external assistance to the affected area, etc.

Catastrophic earthquakes (9 points or more) cover the areas of Kamchatka, the Kuril Islands, Transcaucasia and a number of other mountainous regions. In such areas, engineering construction, as a rule, is not carried out.

Strong (from 7 to 9 points) earthquakes occur in a territory stretching in a wide strip from Kamchatka to, including the Baikal region, etc. Only earthquake-resistant construction should be carried out here.

Most of the territory of Russia belongs to the zone in which earthquakes of small magnitude are extremely rare. So, in 1977, shocks of magnitude 4 were registered in Moscow, although the epicenter of the earthquake itself was in the Carpathians.

In spite of great job conducted by scientists on seismic hazard prediction, earthquake prediction is a very difficult problem. To solve it, special maps are built, mathematical models, organize a system of regular observations with the help of seismic instruments, compose a description of past earthquakes based on the study of a complex of factors, including the behavior of living organisms, analyzing their geographical distribution.

Most effective ways flood control - flow regulation, as well as the construction of protective dams and dams. So, the length of dams and dikes is more than 1800 miles. Without this protection, 2/3 of its territory would be flooded every day by the tide. A dam was built to protect against floods. The peculiarity of this implemented project is that it requires high-quality cleaning Wastewater of the city and the normal functioning of the culverts in the dam itself, which was not adequately provided for in the dam project. The construction and operation of such engineering facilities also require an assessment of possible environmental consequences.

Floods - an annual recurring seasonal long and significant increase in the water content of rivers, which are accompanied by an increase in the water level in the channel and flooding of the floodplain - one of the main causes of floods.

Large floodplain floods during floods are observed in most of the territory of the CIS, and in Eastern Europe.

sat down — mud or mud-stone flows that suddenly arise in the channels of mountain rivers and are characterized by a sharp short-term (1-3 hours) rise in the water level in the rivers, undulating movement and the absence of a complete periodicity. Mudflow can occur when heavy rains fall, intense melting of snow and ice, less often due to volcanic eruptions, breakthroughs of mountain lakes, as well as as a result of economic activity person (explosive work, etc.). The prerequisites for the formation are: a cover of slope deposits, significant slopes of mountain slopes, increased soil moisture. According to the composition, mud-stone, water-stone, mud and water-grown mudflows are distinguished, in which the content of solid material ranges from 10-15 to 75%. Separate fragments carried by mudflows weigh more than 100-200 tons. The speed of mudflows reaches 10 m/s, and the volume is hundreds of thousands, and sometimes even millions of cubic meters. Having a large mass and speed of movement, mudflows often bring destruction, acquiring the nature of a natural disaster in the most catastrophic cases. So, in 1921, a catastrophic mudflow destroyed Alma-Ata, killing about 500 people. At present, this city is reliably protected by an anti-mudflow dam and a complex of special engineering structures. The main measures to combat mudflows are associated with fixing the vegetation cover on the mountain slopes, with the preventive descent of the mountainous ones threatening a breakthrough, with the construction of dams and various mudflow protection structures.

Avalanches — masses of snow falling down steep mountain slopes. Especially often avalanches descend in cases where snow masses form ramparts or snow cornices hanging over the underlying slope. Avalanches occur when snow stability is disturbed on a slope under the influence of heavy snowfalls, intensive snowmelt, rains, non-crystallization of the snow mass with the formation of a weakly connected deep horizon. Depending on the nature of the movement of snow along the slopes, there are: axial - snow landslides sliding along the entire surface of the slope; flume avalanches - moving along hollows, logs and erosion furrows, jumping from ledges. When leaving the dry snow, a destructive air wave propagates ahead. The avalanches themselves also have enormous destructive power, since their volume can reach 2 million m 3, and the impact force is 60-100 t/m2. Usually, avalanches, although with varying degrees of constancy, are confined year after year to the same places - centers different sizes and configuration.

To combat avalanches, protection systems have been developed and are being created that provide for the placement of snow shields, the prohibition of felling and forest planting on avalanche-prone slopes, the shelling of dangerous slopes from artillery, the construction of avalanche ramparts and ditches. The fight against avalanches is very difficult and requires large material costs.

In addition to the catastrophic processes described above, there are also such as collapse, landslide, sinking, subsidence, destruction of coasts, etc. All these processes lead to the movement of matter, often on a large scale. The fight against these phenomena should be aimed at weakening and preventing (where possible) the processes that cause a negative impact on the stability of engineering structures that endanger people's lives.

All processes in nature are cyclical. At a certain time there is a change of seasons, each of which is beautiful in its own way and for a certain season its own characteristics are characteristic. natural phenomena. Some phenomena seem so simple and natural that we do not notice them and take them for granted, but, meanwhile, each natural phenomenon is unique, even the most familiar of them is subject to the corresponding laws of nature.
Consider natural phenomena, common and rare, characteristic of our latitudes.

Dew. The air contains water vapor, which condenses as it falls to the ground. The dew appears cool summer evening and in the early morning on the leaves and stems of plants. When the thermometer drops below zero, frost forms.

Rainbow- This is an optical natural phenomenon that occurs in the atmosphere as a result of the refraction of sunlight by raindrops. A rainbow can be observed during or immediately after a summer rain, when sunlight passes through the rain.

Thunderstorm represents electrical discharges that are collected in the layers of the atmosphere.
A thundercloud is charged with positive and negative particles. Lightning occurs due to the collision of clouds with the signs "-" and "+".
Between earth and cloud arises electric field, the air is ionized. When the heat reaches its peak, a breakdown occurs and lightning strikes the ground.
sound waves at electrical discharges create an echo, i.e. peals of thunder.
Lightning comes in different types: linear, the most common, as well as rarer, pearl and ball. Ball lightning has the shape of a ball or oval. The phenomenon quickly arises and also quickly disappears. Predict the trajectory fireball almost impossible.
Pearl Lightning appear after the linear ones and have a rounded shape, accompanied by thunder.

Another wonderful and mysterious phenomenon, which can be seen almost all year round is an meteoritic or star Rain. On a dark clear night, bright light rays line the sky. The intensity of the streams is different, depending on the season, and such stellar showers are repeated every year at about the same time, only the intensity and brightness are different. The most spectacular starfall can be observed on August 12 and the peak of Perseid activity.

Northern Lights- a fascinating and very spectacular natural phenomenon.
On the territory of our country, the northern lights can be seen in almost all regions located near the Arctic Circle, from Murmansk to Chukotka.
The northern lights are a bright glow in the dark sky, which is formed due to the interaction of the upper atmosphere with the charged particles of the sun.
The more active the sun, the more likely the beginning of the northern lights. The spectacle is accompanied by a crash.

Halo. This phenomenon is scientifically substantiated and is not rare. Sometimes a bright circle of light can be observed in the sky, formed by the refraction of the rays of the sun in the ice crystals contained in the body of the cloud. In the immediate vicinity of the main circle, one can observe luminous circles of smaller diameter. The phenomenon of the halo looks very impressive.

Eclipse occurs at the moment when the glow of one object is blocked by another object.
Moon eclipse occurs when the Moon is in the cone-shaped zone of the shadow cast by the Earth.
Solar eclipse happens when the moon is between the place of observation and the sun and obscures it. Immediately before the eclipse, the Moon looks at the Earth with its unlit side and before the eclipse there is a new moon, the moon is not visible in the sky.

natural phenomena are truly unique and of great interest to researchers and amateurs. There are also dangerous phenomena, such as, for example, a volcanic eruption, a hurricane or a flood. They have a powerful destructive force, before which a person is helpless. Nature is fraught with a myriad of mysteries and questions, the answers to which will be given to future generations of scientists and researchers.