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

According to the size of the one-time damage impact, hazardous natural phenomena vary from minor to those creating natural disasters.

A natural disaster is any unpreventable, menacingly destructive natural phenomenon that causes economic damage and poses a threat to the health and lives of people. When it comes to measuring losses, the term used is an emergency situation (ES). During an emergency, absolute losses are measured first of all - for quick response, for deciding on the necessary external assistance to the affected area, etc.

Catastrophic earthquakes (magnitude 9 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 a zone in which small earthquakes are extremely rare. Thus, in 1977, tremors with a magnitude of 4 were recorded in Moscow, although the epicenter of the earthquake itself was in the Carpathians.

Despite much work done by scientists on seismic hazard prediction, earthquake prediction is a very difficult problem. To solve it, special maps and mathematical models are built, a system of regular observations is organized using seismic instruments, and a description of past earthquakes is compiled based on the study of a complex of factors, including the behavior of living organisms, analyzing their geographical distribution.

The most effective ways to combat floods are flow regulation, as well as the construction of protective dams and dams. Thus, the length of dams and dams is more than 1800 miles. Without this protection, 2/3 of its territory would be inundated 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 treatment of the city’s wastewater and the normal functioning of culverts in the dam itself, which was not adequately provided for in the dam design. The construction and operation of such engineering facilities also require an assessment of possible environmental consequences.

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

Large flooding of the floodplain during floods is observed in most of the CIS, Eastern Europe.

Sat down — mud or mud-stone flows that suddenly appear in the beds of mountain rivers and are characterized by a sharp short-term (1 - 3 hours) rise in water level in rivers, wave-like movement and the absence of complete periodicity. Mudflows can occur due to heavy rainfall, intensive melting of snow and ice, less often due to volcanic eruptions, breaches of mountain lakes, as well as as a result of human economic activity (blasting, etc.). The prerequisites for formation are: a cover of slope deposits, significant slopes of mountain slopes, increased soil moisture. Based on their composition, mud-stone, water-stone, mud and water-and-wood mudflows are distinguished, in which the content of solid material ranges from 10-15 to 75%. Individual debris carried by mudflows weighs more than 100-200 tons. The speed of mudflows reaches 10 m/s, and the volumes are hundreds of thousands and sometimes millions of cubic meters. Possessing large mass and speed of movement, mudflows often cause destruction, acquiring in the most catastrophic cases the character of a natural disaster. Thus, in 1921, a catastrophic mudflow destroyed Alma-Ata, killing about 500 people. Currently, this city is reliably protected by a mudflow dam and a complex of special engineering structures. The main measures to combat mudflows are associated with the consolidation of vegetation cover on mountain slopes, with the preventive descent of mountain slopes that threaten to break through, with the construction of dams and various mudflow protection structures.

Avalanches — masses of snow cascading down steep mountain slopes. Avalanches occur especially often in cases where snow masses form shafts or snow cornices overhanging the underlying slope. Avalanches occur when the stability of snow on a slope is disrupted under the influence of heavy snowfalls, intense snowmelt, rain, non-crystallization of the snow layer with the formation of a weakly connected deep horizon. Depending on the nature of the movement of snow along the slopes, they are distinguished: axial - snow slides sliding along the entire surface of the slope; flume avalanches - moving along hollows, ravines and erosion furrows, jumping from ledges. When dry snow melts, a destructive air wave propagates ahead. Avalanches themselves also have enormous destructive power, since their volume can reach 2 million m3, and the impact force is 60-100 t/m2. Typically, avalanches, although with varying degrees of consistency, are confined to the same places from year to year - centers of different sizes and configurations.

To combat avalanches, protection systems have been developed and are being created, which include the placement of snow shields, the prohibition of logging and tree planting on avalanche-prone slopes, the shelling of dangerous slopes with artillery guns, 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, sliding, swimming, subsidence, destruction of banks, etc. All of these processes result in the movement of matter, often on a large scale. The fight against these phenomena should be aimed at weakening and preventing (where possible) processes that cause a negative impact on the stability of engineering structures that endanger people's lives.

Man has long considered himself the “crown of nature,” vainly believing in his superiority and treating the environment in accordance with his status, which he has assigned to himself. However, nature proves every time that human judgments are wrong, and thousands of victims of natural disasters make us think about the real place of homo sapiens on planet Earth.
1 place. Earthquake

An earthquake is tremors and vibrations of the earth's surface that occur when tectonic plates shift. There are dozens of earthquakes around the world every day, but fortunately, only a few of them cause widespread destruction. The most destructive earthquake in history occurred in 1556 in the Chinese province of Xi'an. Then 830 thousand people died. For comparison: 12.5 thousand people became victims of a magnitude 9.0 earthquake in Japan in 2011.

2nd place. Tsunami

Tsunami is a Japanese term for an unusually high ocean wave. Tsunamis most often occur in areas of increased seismic activity. According to statistics, it is the tsunami that leads to the greatest number of human casualties. The highest wave was recorded in 1971 in Japan near Ishigaki Island: it reached 85 meters at a speed of 700 km/h. And the Tsunami caused by an earthquake off the coast of Indonesia claimed the lives of 250 thousand people.

3rd place. Drought

Drought is a prolonged absence of precipitation, most often at elevated temperatures and low air humidity. One of the most destructive was the drought in the Sahel (Africa), a semi-desert separating the Sahara from fertile lands. The drought there lasted from 1968 to 1973 and killed about 250 thousand people.

4th place. Flood

Flood is a significant rise in water levels in rivers or lakes as a result of heavy rains, melting ice, etc. One of the most devastating floods occurred in Pakistan in 2010. More than 800 people died then, and more than 20 million people in the country were affected by the disaster and were left homeless and without food.

5th place. Landslides

A landslide is a flow of water, mud, stones, trees and other debris that occurs mainly in mountainous areas due to prolonged rainfall. The largest number of victims was recorded in a landslide in China in 1920, which claimed the lives of 180 thousand people.

6th place. Eruption

Volcanism is a set of processes associated with the movement of magma in the mantle, upper layers of the earth's crust and on the surface of the earth. Currently, there are about 500 active volcanoes, and about 1000 dormant. The largest eruption occurred in 1815. Then the awakened Tambora volcano was heard at a distance of 1250 km. Directly from the eruption, and then from hunger, 92 thousand people died. Two days at a distance of 600 km. Due to volcanic dust, there was pitch darkness, and 1816 was called “the year without summer” by Europe and America.

7th place. Avalanche

An avalanche is the overthrow of a mass of snow from mountain slopes, most often caused by prolonged snowfalls and the growth of a snow cap. Most people died from avalanches during the First World War. Then about 80 thousand people died from artillery volleys that caused avalanches.

8th place. Hurricane

Hurricane (tropical cyclone, typhoon) is an atmospheric phenomenon characterized by low pressure and strong wind. Hurricane Katrina, which struck the US coast in August 2005, is considered the most destructive. The states that suffered the most were New Orleans and Louisiana, where 80% of the territory was flooded. 1,836 people died and damage amounted to $125 billion.

9th place. Tornado

A tornado is an atmospheric vortex that stretches from the mother thundercloud to the ground in the form of a long arm. The speed inside it can reach up to 1300 km/h. Tornadoes mainly threaten the central part of North America. So, in the spring of 2011, a series of destructive tornadoes passed through this country, which were called one of the most catastrophic in US history. The highest death toll was recorded in Alabama – 238 people. In total, the disaster claimed the lives of 329 people.

10th place. Sandstorm

A sandstorm is a strong wind that can lift the top layer of earth and sand (up to 25 cm) into the air and transport it over long distances in the form of dust particles. There are known cases of people dying from this scourge: in 525 BC. In the Sahara, fifty thousand troops of the Persian king Cambyses died due to a sandstorm.

Hazardous natural phenomena mean extreme climatic or meteorological phenomena that occur naturally at one point or another on the planet. In some regions, such hazardous events may occur with greater frequency and destructive force than in others. Dangerous natural phenomena develop into natural disasters when the infrastructure created by civilization is destroyed and people themselves die.

1. Earthquakes

Among all natural hazards, earthquakes should take first place. In places where the earth's crust breaks, tremors occur, which cause vibrations of the earth's surface with the release of gigantic energy. The resulting seismic waves are transmitted over very long distances, although these waves have the greatest destructive power at the epicenter of the earthquake. Due to strong vibrations of the earth's surface, massive destruction of buildings occurs.
Since quite a lot of earthquakes occur, and the surface of the earth is quite densely built up, the total number of people throughout history who died as a result of earthquakes exceeds the number of all victims of other natural disasters and is estimated in many millions. For example, over the past decade, about 700 thousand people have died from earthquakes around the world. Entire settlements instantly collapsed from the most destructive shocks. Japan is the country most affected by earthquakes, and one of the most catastrophic earthquakes occurred there in 2011. The epicenter of this earthquake was in the ocean near the island of Honshu; on the Richter scale, the force of the tremors reached 9.1. Powerful aftershocks and the subsequent destructive tsunami disabled the Fukushima nuclear power plant, destroying three out of four power units. Radiation covered a significant area around the station, making densely populated areas, so valuable in Japanese conditions, uninhabitable. The colossal tsunami wave turned into mush what the earthquake could not destroy. Only officially over 16 thousand people died, to which we can safely include another 2.5 thousand who are considered missing. In this century alone, destructive earthquakes occurred in the Indian Ocean, Iran, Chile, Haiti, Italy, and Nepal.

2. Tsunami waves

A specific water disaster in the form of tsunami waves often results in numerous casualties and catastrophic destruction. As a result of underwater earthquakes or shifts of tectonic plates in the ocean, very fast but subtle waves arise, which grow into huge ones as they approach the shores and reach shallow waters. Most often, tsunamis occur in areas with increased seismic activity. A huge mass of water, quickly approaching the shore, destroys everything in its path, picks it up and carries it deep into the coast, and then carries it into the ocean with a reverse current. People, unable to sense danger like animals, often do not notice the approach of a deadly wave, and when they notice, it is too late.
A tsunami usually kills more people than the earthquake that caused it (most recently in Japan). In 1971, the most powerful tsunami ever observed occurred there, the wave of which rose 85 meters at a speed of about 700 km/h. But the most catastrophic was the tsunami observed in the Indian Ocean (source - an earthquake off the coast of Indonesia), which claimed the lives of about 300 thousand people along a large part of the Indian Ocean coast.

A tornado (in America this phenomenon is called a tornado) is a fairly stable atmospheric vortex, most often occurring in thunderclouds. He's visual...

3. Volcanic eruption

Throughout its history, humanity has remembered many catastrophic volcanic eruptions. When the pressure of magma exceeds the strength of the earth's crust at the weakest points, which are volcanoes, it ends in an explosion and outpouring of lava. But the lava itself, from which you can simply walk away, is not so dangerous as the hot pyroclastic gases rushing from the mountain, penetrated here and there by lightning, as well as the noticeable influence of the strongest eruptions on the climate.
Volcanologists count about half a thousand dangerous active volcanoes, several dormant supervolcanoes, not counting thousands of extinct ones. Thus, during the eruption of Mount Tambora in Indonesia, the surrounding lands were plunged into darkness for two days, 92 thousand inhabitants died, and cold temperatures were felt even in Europe and America.
List of some major volcanic eruptions:

• Volcano Laki (Iceland, 1783). As a result of that eruption, a third of the island's population died - 20 thousand inhabitants. The eruption lasted for 8 months, during which streams of lava and liquid mud erupted from volcanic fissures. Geysers have become more active than ever. Living on the island at this time was almost impossible. The crops were destroyed and even the fish disappeared, so the survivors starved and suffered from unbearable living conditions. This may be the longest eruption in human history.
• Volcano Tambora (Indonesia, Sumbawa Island, 1815). When the volcano exploded, the sound of the explosion spread over 2 thousand kilometers. Even the remote islands of the archipelago were covered with ash, and 70 thousand people died from the eruption. But even today, Tambora is one of the highest mountains in Indonesia that remains volcanically active.
• Volcano Krakatoa (Indonesia, 1883). 100 years after Tambora, another catastrophic eruption occurred in Indonesia, this time “blowing the roof off” (literally) the Krakatoa volcano. After the catastrophic explosion that destroyed the volcano itself, frightening rumbles were heard for another two months. A gigantic amount of rock, ash and hot gases were thrown into the atmosphere. The eruption was followed by a powerful tsunami with wave heights of up to 40 meters. These two natural disasters together destroyed 34 thousand islanders along with the island itself.
• Volcano Santa Maria (Guatemala, 1902). After a 500-year hibernation, this volcano woke up again in 1902, beginning the 20th century with the most catastrophic eruption, which resulted in the formation of a one and a half kilometer crater. In 1922, Santa Maria reminded itself again - this time the eruption itself was not too strong, but the cloud of hot gases and ash brought the death of 5 thousand people.

4. Tornadoes

Throughout the history of mankind, powerful earthquakes have repeatedly caused colossal damage to people and caused a huge number of casualties among the population...

A tornado is a very impressive natural phenomenon, especially in the United States, where it is called a tornado. This is an air flow twisted in a spiral into a funnel. Small tornadoes resemble slender, narrow pillars, and giant tornadoes can resemble a mighty carousel reaching towards the sky. The closer you are to the funnel, the stronger the wind speed is; it begins to drag along increasingly larger objects, up to cars, carriages and light buildings. In the “tornado alley” of the United States, entire city blocks are often destroyed and people die. The most powerful vortices of the F5 category reach a speed of about 500 km/h at the center. The state that suffers the most from tornadoes every year is Alabama.

There is a type of fire tornado that sometimes occurs in areas of massive fires. There, from the heat of the flame, powerful upward currents are formed, which begin to twist into a spiral, like an ordinary tornado, only this one is filled with flame. As a result, a powerful draft is formed near the surface of the earth, from which the flame grows even stronger and incinerates everything around. When a catastrophic earthquake occurred in Tokyo in 1923, it caused massive fires that led to the formation of a fire tornado that rose 60 meters. The column of fire moved towards the square with frightened people and burned 38 thousand people in a few minutes.

5. Sandstorms

This phenomenon occurs in sandy deserts when strong winds rise. Sand, dust and soil particles rise to a fairly high altitude, forming a cloud that sharply reduces visibility. If an unprepared traveler gets caught in such a storm, he may die from grains of sand falling into his lungs. Herodotus described the story as 525 BC. e. In the Sahara, a 50,000-strong army was buried alive by a sandstorm. In Mongolia in 2008, 46 people died as a result of this natural phenomenon, and a year earlier two hundred people suffered the same fate.

Occasionally, tsunami waves occur in the ocean. They are very insidious - in the open ocean they are completely invisible, but as soon as they approach the coastal shelf, they...

6. Avalanches

Avalanches periodically fall from snow-capped mountain peaks. Climbers especially often suffer from them. During the First World War, up to 80 thousand people died from avalanches in the Tyrolean Alps. In 1679, half a thousand people died from snow melting in Norway. In 1886, a major disaster occurred, as a result of which the “white death” claimed 161 lives. The records of Bulgarian monasteries also mention human casualties from avalanches.

7. Hurricanes

In the Atlantic they are called hurricanes, and in the Pacific they are called typhoons. These are huge atmospheric vortices, in the center of which the strongest winds and sharply reduced pressure are observed. Several years ago, the devastating Hurricane Katrina swept over the United States, which particularly affected the state of Louisiana and the densely populated city of New Orleans, located at the mouth of the Mississippi. 80% of the city was flooded, and 1,836 people died. Other famous destructive hurricanes include:

• Hurricane Ike (2008). The diameter of the vortex was over 900 km, and in its center the wind blew at a speed of 135 km/h. In the 14 hours that the cyclone moved across the United States, it managed to cause $30 billion worth of destruction.
• Hurricane Wilma (2005). This is the largest Atlantic cyclone in the entire history of weather observations. The cyclone, which originated in the Atlantic, made landfall several times. The damage it caused amounted to $20 billion, killing 62 people.
• Typhoon Nina (1975). This typhoon was able to breach China's Bangqiao Dam, causing the destruction of the dams below and causing catastrophic flooding. The typhoon killed up to 230 thousand Chinese.

8. Tropical cyclones

These are the same hurricanes, but in tropical and subtropical waters, representing huge low-pressure atmospheric systems with winds and thunderstorms, often exceeding a thousand kilometers in diameter. Near the surface of the earth, winds at the center of the cyclone can reach speeds of more than 200 km/h. Low pressure and wind cause the formation of a coastal storm surge - when colossal masses of water are thrown ashore at high speed, washing away everything in its path.

Environmental disasters have their own specifics - during them not a single person may die, but at the same time a very significant...

9. Landslide

Prolonged rains can cause landslides. The soil swells, loses stability and slides down, taking with it everything that is on the surface of the earth. Most often, landslides occur in the mountains. In 1920, the most devastating landslide occurred in China, under which 180 thousand people were buried. Other examples:

• Bududa (Uganda, 2010). Due to mudflows, 400 people died, and 200 thousand had to be evacuated.
• Sichuan (China, 2008). Avalanches, landslides and mudflows caused by an 8-magnitude earthquake claimed 20 thousand lives.
• Leyte (Philippines, 2006). The downpour caused a mudslide and landslide that killed 1,100 people.
• Vargas (Venezuela, 1999). Mudflows and landslides after heavy rains (almost 1000 mm of precipitation fell in 3 days) on the northern coast led to the death of almost 30 thousand people.

10. Ball lightning

We are accustomed to ordinary linear lightning accompanied by thunder, but ball lightning is much rarer and more mysterious. The nature of this phenomenon is electrical, but scientists cannot yet give a more accurate description of ball lightning. It is known that it can have different sizes and shapes, most often they are yellowish or reddish luminous spheres. For unknown reasons, ball lightning often defies the laws of mechanics. Most often they occur before a thunderstorm, although they can also appear in absolutely clear weather, as well as indoors or in an airplane cabin. The luminous ball hovers in the air with a slight hiss, then can begin to move in any direction. Over time, it seems to shrink until it disappears completely or explodes with a roar. But the damage ball lightning can cause is very limited.

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

TORNADOES AND OTHER TYPES OF TOrnadoes

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 arm 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 the earth's surface. A tornado can be completely hidden by a wall of rain or dust. These tornadoes are especially dangerous because even experienced meteorologists may not recognize them.

Tornado with lightning:

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, gusty winds, and large hail:

Thunderclouds:

View of a hurricane tornado from space:

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

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.

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

Sandspout:

Or a firestorm forms 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 masses of air from the periphery enter in its place, which immediately heat up. Steady flows are formed, spiraling from the ground to a height of up to 5 km. A chimney effect occurs. The pressure of hot air reaches hurricane speeds. The temperature rises to 1000˚C. 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 has burned.

A site is a funnel-shaped air-water vortex, similar in nature to an ordinary tornado, formed over the surface of a large body of water and connected to a cumulus cloud. A waterspout can form when a regular tornado passes over a water surface. Unlike a classic tornado, a waterspout lasts 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 hurricane winds.

DUST OR SAND STORMS

Sand (dust) storm is a dangerous atmospheric phenomenon that manifests itself in the form of wind transfer of large quantities of soil particles, dust or small 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 impaired. 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 occur 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 you, as if you had suddenly found yourself in a vacuum. This silence is depressing, creating an inexplicable anxiety inside you.

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

Sandstorm in Golmud village, Qinghai province, China, 2010:

Red sandstorm in Australia:

TSUNAMI

is a dangerous natural disaster consisting of sea waves resulting from the shifting of the seabed during underwater and coastal earthquakes. Once formed in any place, a tsunami can spread at high speed (up to 1000 km/h) over several thousand kilometers, with the tsunami height initially ranging 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 washed ashore lead to flooding and destruction of the area, as well as 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 this is a series of waves that roll onto the shore at intervals of 1 hour or more.

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

CATASTROPHIC FLOODS

Flood— flooding of the territory with water, which is a natural disaster. Floods come in different types and are caused by different reasons. Catastrophic floods lead to loss of life, irreparable environmental damage, and cause material damage, covering vast areas within one or more water systems. At the same time, economic activity and production activities are completely paralyzed, and the lifestyle of the population is temporarily changed. The evacuation of hundreds of thousands of people, an inevitable humanitarian catastrophe requires the participation of the entire world community, the problem of one country becomes a problem of the whole world.

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

Flooding in New Orleans after a hurricane. New Orleans (USA) stands on damp soil that the city cannot support. Orleans is slowly sinking into the ground, and the Gulf of Mexico is gradually rising around it. Much of New Orleans is already 1.5 to 3 meters below sea level. This was largely due to Hurricane Katrina in 2005:

Flood in Germany, in the Rhine River basin (2013):

Flood in Iowa, USA (2008):

THUNDERLIGHTNING

Lightning discharges (lightning) represent a giant electrical spark discharge into the site atmosphere, with a very long spark length, 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 (on average 2.5 km), and a significant part of this channel is located inside a thundercloud. Some discharges extend up to 20 km in the atmosphere. The current in a lightning discharge reaches 10-20 thousand amperes, so not all people survive a lightning strike.

forest fire- This is the spontaneous, uncontrolled spread of fire across forest areas. The causes of fires in the forest can be natural (lightning, drought, etc.) or artificial, when the cause is people. There are several types of forest fires.

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

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

Horse forest fire covers leaves, needles, branches and the entire crown, 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-lying crowns, in stands of different ages, as well as with abundant coniferous undergrowth. This is usually the final stage of a fire.

VOLCANOES

Volcanoes 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, rocks and pyroclastic flows. When molten magma pours through cracks in the earth's crust, the volcano erupts, a site named after 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:

Klyuchevskoy Volcano 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:

EARTHQUAKES

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

Japan earthquake followed by tsunami (2011):

LANDSLIDE

Landslide- a separated mass of loose rocks, slowly and gradually or abruptly sliding along the inclined plane of separation, while often maintaining its coherence, solidity and without overturning its soil.

VILLAGE

Sel- a flow with a very high concentration of mineral particles, stones and rock fragments (something between a liquid and a solid mass), suddenly appearing in the basins of small mountain rivers and usually caused by rainfall or rapid snow melting.

SNOW AVALANCHES

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

This is one of record avalanches measuring 600 thousand cubic meters. The film crew was not injured:

“This is the consequence of an avalanche - snow dust, it flew up 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. The fine, fine snow made it difficult to breathe. My arms and legs instantly went numb. I didn't see anyone around. Although there were people nearby,” said Anton Voitsekhovsky, a member of the film crew.

| Materials for life safety lessons for grade 7 | Lesson plan for the academic year | Natural emergencies

Basics of life safety
7th grade

Lesson 1
Natural emergencies

There are concepts "hazardous natural phenomenon" And "disaster".

Dangerous natural phenomenon - this is an event of natural origin or the result of natural processes, which, due to their intensity, scale of distribution and duration, can have a damaging effect on people, economic objects and the environment.

TO natural hazards include earthquakes, volcanic eruptions, floods, tsunamis, hurricanes, storms, tornadoes, landslides, mudflows, forest fires, sudden thaws, cold snaps, warm winters, severe thunderstorms, droughts, etc. But not all, but only those that negatively impact people's livelihoods, the economy and the environment.

Such phenomena cannot include, for example, an earthquake in a desert area where no one lives, or a powerful landslide in an uninhabited mountainous area. They also do not include phenomena that occur in places where people live, but do not cause a sharp change in their living conditions, do not lead to death or injury to people, destruction of buildings, communications, etc.

Disaster - is a destructive natural and (or) natural-anthropogenic phenomenon or process of significant scale, as a result of which a threat to the life and health of people may arise or has arisen, destruction or destruction of material assets and components of the natural environment may occur.

They arise under the influence of atmospheric phenomena (hurricanes, heavy snowfalls, torrential rains), fire (forest and peat fires), changes in water levels in reservoirs (floods, floods), processes occurring in the soil and the earth's crust (volcanic eruptions, earthquakes, landslides , mudflows, landslides, tsunamis).

Approximate ratio of the frequency of occurrence of hazardous natural phenomena by their types.

Natural disasters are usually natural emergencies. They can occur independently of each other, and sometimes one natural disaster leads to another. As a result of earthquakes, for example, avalanches or landslides can occur. And some natural disasters occur due to human activity, sometimes unreasonable (a cigarette butt thrown unextinguished or an unextinguished fire, for example, often leads to a forest fire, explosions in mountainous areas during road construction lead to landslides, landslides, avalanches).

So, the occurrence of a natural emergency is a consequence of a natural phenomenon in which there is a direct threat to the life and health of people, material values ​​and the natural environment are destroyed and destroyed.

Typification of natural phenomena by degree of danger

Such phenomena can have different origins, which became the basis for the classification of natural emergencies shown in Diagram 1.

Each natural disaster has its own impact on a person and his health. People suffer the most from floods, hurricanes, earthquakes and droughts. And only about 10% of the damage it causes comes from other natural disasters.

The territory of Russia is exposed to a wide variety of natural hazards. At the same time, there are significant differences in their manifestation here compared to other countries. Thus, the historically established zone of the main distribution of the population of Russia (from the European part in the south of Siberia to the Far East) approximately coincides with the zone of the least manifestation of such natural hazards as earthquakes, hurricanes and tsunamis (except for the Far East). At the same time, the high prevalence of unfavorable and dangerous natural processes and phenomena is associated with cold, snowy winters. In general, the damage caused by natural emergencies in Russia is below the global average due to a significantly lower population density and the location of hazardous industries, as well as as a result of the adoption of preventive measures.