The most terrible natural disasters. Natural disasters and cataclysms always cause huge damage to a person.

Natural disasters and their impact on change

physical and geographical location

The physical and geographical position is the spatial location of any area in relation to the physical and geographical data (equator, prime meridian, mountain systems, seas and oceans, etc.).

The physical and geographical position is determined by geographical coordinates (latitude, longitude), absolute altitude in relation to sea level, proximity (or remoteness) to the sea, rivers, lakes, mountains, etc., position in the composition (location) of natural (climatic, soil-vegetative, zoogeographic) zones. This is the so-called. elements or factors of physical and geographical location.

The physical and geographical position of any locality is purely individual, unique. The place occupied by each territorial entity, not only individually in itself (in the system geographical coordinates), but also in its spatial environment, i.e., in its location in relation to the elements of the physical and geographical position. Consequently, a change in the physical-geographical position of any locality leads, as a rule, to a change in the physical-geographical position of neighboring localities.

A rapid change in the physical and geographical position can only be due to natural disasters or the activities of man himself.

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 their economy. Cataclysmic natural disasters include those that change the face of the earth.

These are catastrophic processes of endogenous and exogenous origin: earthquakes, volcanic eruptions, tsunamis, floods, avalanches and mudflows, landslides, subsidence of soils, sudden onset of the sea, global climate change on Earth, etc.

In this paper, we will consider physical and geographical changes that have ever occurred or are occurring in our time under the influence of natural disasters.

CHARACTERISTICS OF NATURAL DISASTERS

earthquakes

Earthquakes are the main source of physical and geographical changes.

An earthquake is called concussion earth's crust, underground impacts and fluctuations of the earth's surface, caused mainly by tectonic processes. They manifest themselves in the form of tremors, often accompanied by an underground rumble, undulating vibrations of the soil, the formation of cracks, the destruction of buildings, roads and, most sadly, human casualties. Earthquakes play a significant role in the life of the planet. More than 1 million tremors are recorded annually on Earth, which averages about 120 shocks per hour or two shocks per minute. We can say that the earth is in a state of constant trembling. Fortunately, few of them are destructive and catastrophic. There is an average of one catastrophic earthquake and 100 destructive ones per year.

Earthquakes occur as a result of the pulsating-oscillatory development of the lithosphere - its compression in some regions and expansion in others. At the same time, tectonic breaks, displacements and uplifts are observed.

Currently on the globe zones of earthquakes of different activity are allocated. The areas of strong earthquakes include the territories of the Pacific and Mediterranean belts. In our country, more than 20% of the territory is prone to earthquakes.

Catastrophic earthquakes (9 points or more) cover the areas of Kamchatka, the Kuril Islands, Pamir, Transbaikalia, Transcaucasia and a number of other mountainous regions.

Strong (from 7 to 9 points) earthquakes occur in a territory stretching in a wide strip from Kamchatka to the Carpathians, including Sakhalin, the Baikal region, the Sayans, Crimea, Moldova, etc.

As a result of catastrophic earthquakes, large disjunctive dislocations appear in the earth's crust. Thus, during the catastrophic earthquake on December 4, 1957 in the Mongolian Altai, the Bogdo fault, about 270 km long, appeared, and the total length of the resulting faults reached 850 km.

Earthquakes are caused by sudden, rapid displacements of the wings of existing or newly formed tectonic faults; the voltages that arise in this case are capable of being transmitted over long distances. The occurrence of earthquakes on large faults occurs during a long-term displacement in opposite directions of tectonic blocks or plates that are in contact along the fault. At the same time, cohesive forces keep the fault wings from slipping, and the fault zone experiences a gradually increasing shear deformation. When it reaches a certain limit, the fault “rips open” and its wings are displaced. Earthquakes on newly formed faults are considered as a result of the regular development of systems of interacting cracks that combine into a zone of increased concentration of faults, in which a main fault is formed, accompanied by an earthquake. The volume of the medium, where part of the tectonic stresses are removed and some of the accumulated potential energy of deformation is released, is called the earthquake source. The amount of energy released during one earthquake depends mainly on the size of the shifted fault surface. The maximum known length of faults that rupture during an earthquake is in the range of 500-1000 km (Kamchatka - 1952, Chile - 1960, etc.), the wings of the faults were displaced to the sides up to 10 m. The spatial orientation of the fault and the direction of displacement its wings are called the earthquake focal mechanism.

Earthquakes capable of changing the face of the Earth are catastrophic earthquakes with magnitude X-XII points. Geological consequences of earthquakes, leading to physical and geographical changes: cracks appear on the ground, sometimes gaping;

air, water, mud or sand fountains appear, while accumulations of clay or piles of sand are formed;

some springs and geysers stop or change their action, new ones appear;

groundwater becomes cloudy (stirred);

landslides, mud and mudflows, landslides occur;

there is a liquefaction of the soil and sandy-clayey rocks;

underwater creep occurs, and turbidity (turbidite) flows are formed;

coastal cliffs, river banks, bulk areas collapse;

seismic sea waves (tsunami) occur;

snow avalanches break down;

icebergs break off ice shelves;

zones of rift-type disturbances with internal ridges and dammed lakes are formed;

the soil becomes uneven with areas of subsidence and swelling;

seiches occur on lakes (standing waves and churning of waves off the coast);

the regime of ebbs and flows is violated;

volcanic and hydrothermal activity is activated.

Volcanoes, tsunamis and meteorites

Volcanism is a set of processes and phenomena associated with the movement of magma in the upper mantle, the earth's crust and on the surface of the earth. As a result of volcanic eruptions, volcanic mountains, volcanic lava plateaus and plains, crater and dam lakes, mud flows, volcanic tuffs, cinders, breccias, bombs, ash are formed, volcanic dust and gases are emitted into the atmosphere.

Volcanoes are located in seismically active zones, especially in the Pacific. In Indonesia, Japan, Central America there are several dozen active volcanoes - in total on land from 450 to 600 active and about 1000 "sleeping" volcanoes. About 7% of the world's population is dangerously close to active volcanoes. There are at least several dozen large underwater volcanoes on the mid-ocean ridges.

In Russia, Kamchatka, the Kuril Islands, and Sakhalin are exposed to the danger of volcanic eruptions and tsunamis. There are extinct volcanoes in the Caucasus and Transcaucasia.

The most active volcanoes erupt on average once every few years, all currently active volcanoes erupt on average once every 10-15 years. In the activity of each volcano there are, apparently, periods of relative decrease and increase in activity, measured in thousands of years.

Tsunamis often occur during eruptions of island and underwater volcanoes. Tsunami - Japanese term denoting an unusually large sea wave. These are the waves high altitude and destructive forces arising in the zones of earthquakes and volcanic activity of the ocean floor. The speed of such a wave can vary from 50 to 1000 km/h, the height in the area of ​​origin is from 0.1 to 5 m, and near the coast - from 10 to 50 m or more. Tsunamis often cause destruction on the coast - in some cases catastrophic: they lead to erosion of the coast, the formation of turbidity flows. Another cause of ocean tsunamis are underwater landslides and avalanches breaking into the sea.

In the last 50 years, about 70 seismogenic tsunamis of dangerous sizes have been noted, of which 4% in the Mediterranean Sea, 8% in the Atlantic, and the rest in the Pacific Ocean. The most tsunami-prone shores are Japan, the Hawaiian and Aleutian Islands, Kamchatka, the Kuril Islands, Alaska, Canada, the Solomon Islands, the Philippines, Indonesia, Chile, Peru, New Zealand, the Aegean, Adriatic and Ionian Seas. On the Hawaiian Islands, tsunamis with an intensity of 3-4 points occur on average once every 4 years, on the Pacific coast of South America - once every 10 years.

Flooding is a significant flooding of an area as a result of a rise in the water level in a river, lake or sea. Floods are caused by heavy rainfall, melting snow, ice, hurricanes and storms, which contribute to the destruction of bulk structures, dams, dams. Floods can be river (floodplain), surge (on the coasts of the seas), planar (flooding of vast watershed areas), etc.

Large catastrophic floods are accompanied by a rapid and high rise in the water level, a sharp increase in the speed of flows, their destructive power. Devastating floods occur almost every year in various regions of the earth. In Russia, they are most frequent in the south of the Far East.

flooding in the Far East in 2013

Disasters of cosmic origin are of no small importance. The Earth is constantly bombarded by cosmic bodies ranging in size from fractions of a millimeter to several meters. The larger the size of the body, the less often it falls on the planet. Bodies with a diameter greater than 10 m, as a rule, invade the Earth's atmosphere, only weakly interacting with the latter. The bulk of matter reaches the planet. The speed of cosmic bodies is enormous: approximately from 10 to 70 km/s. Their collision with the planet leads to strong earthquakes, an explosion of the body. At the same time, the mass of the destroyed substance of the planet is hundreds of times greater than the mass of the fallen body. Huge masses of dust rise into the atmosphere, shielding the planet from solar radiation. The earth is cooling. The so-called "asteroid" or "comet" winter is coming.

According to one hypothesis, one of these bodies that fell in the Caribbean hundreds of millions of years ago led to significant physical and geographical changes in the area, the formation of new islands and reservoirs, and along the way to the extinction of most of the animals that inhabited the Earth, in particular dinosaurs. .

Some space bodies could fall into the sea in historical times (5-10 thousand years ago). According to one version, the global flood, set out in legends different peoples, could be caused by a tsunami as a result of a space body falling into the sea (ocean). The body could fall into the Mediterranean and the Black Sea. Their coasts were traditionally inhabited by peoples.

Fortunately for us, collisions of the Earth with large cosmic bodies are very rare.

NATURAL DISASTERS IN THE HISTORY OF THE EARTH

Natural disasters of antiquity

According to one of the hypotheses, natural disasters could cause physical and geographical changes in the hypothetical supercontinent Gondwana that existed approximately 200 million years ago in the southern hemisphere of the Earth.

The southern continents have a common history of the development of natural conditions - they were all part of Gondwana. Scientists believe that internal forces Earth (movement of the mantle matter) led to the split and expansion of a single continent. There is a hypothesis about the cosmic causes of the change appearance our planet. It is believed that the collision of an extraterrestrial body with our planet could cause a split of a giant landmass. One way or another, in the spaces between the separate parts of Gondwana, the Indian and Atlantic oceans gradually formed, and the continents occupied their present position.

When trying to "gather" together the pieces of Gondwana, one can come to the conclusion that some land areas are clearly not enough. This suggests that there could be other continents that disappeared as a result of any natural disasters. Until now, disputes about the possible existence of Atlantis, Lemuria and other mysterious lands do not stop.

For a long time it was believed that Atlantis was a huge island (or mainland?), Sunk in the Atlantic Ocean. Currently the bottom Atlantic Ocean well surveyed and found that there is no island that sank 10-20 thousand years ago. Does this mean that Atlantis did not exist? It is quite possible not. They began to look for her in the Mediterranean and Aegean seas. Most likely, Atlantis was located in the Aegean Sea and was part of the Santorian archipelago.

Atlantis

The death of Atlantis is first described in the writings of Plato, the myths about its death come to us from the ancient Greeks (the Greeks themselves could not describe this, due to the lack of writing). Historical information suggests that the natural disaster that destroyed the island of Atlantis was the explosion of the Santorian volcano in the 15th century. BC e.

Everything that is known about the structure and geological history of the Santorian archipelago is very reminiscent of the legends of Plato. As geological and geophysical studies have shown, as a result of the Santorian explosion, at least 28 km3 of pumice and ash were thrown out. Emission products covered the surroundings, the thickness of their layer reached 30-60 m. The ash spread not only within the Aegean Sea, but also in the eastern Mediterranean Sea. The eruption lasted from several months to two years. In the last phase of the eruption, the interior of the volcano collapsed and sank hundreds of meters under the waters of the Aegean Sea.

Another type of natural cataclysm that changed the face of the Earth in ancient times is an earthquake. As a rule, earthquakes cause great damage and cause casualties, but do not change the physical and geographical position of the regions. Such changes lead to the so-called. super earthquakes. Apparently, one of these super-earthquakes was in prehistoric times. A crack up to 10,000 km long and up to 1,000 km wide has been discovered at the bottom of the Atlantic Ocean. This crack could have formed as a result of a super-earthquake. With a focus depth of about 300 km, its energy reached 1.5 1021 J. And this is 100 times more than the energy of the strongest earthquake. This should have led to significant changes in the physical and geographical position of the surrounding territories.

Floods are another no less dangerous element.

One of the global floods could be the already mentioned above biblical Flood. As a result of it, the highest mountain of Eurasia, Ararat, was under water, and some expeditions are still looking for the remains of Noah's Ark on it.

global flood

noah's ark

During the entire Phanerozoic (560 million years), eustatic fluctuations did not stop, and in some periods the water level of the World Ocean rose by 300-350 m relative to its present position. At the same time, significant areas of land (up to 60% of the area of ​​\u200b\u200bthe continents) were flooded.

Changed the appearance of the Earth in ancient times and cosmic bodies. The fact that in prehistoric times asteroids fell into the ocean is evidenced by craters at the bottom of the oceans:

Mjolnir crater in the Barents Sea. Its diameter was about 40 km. It arose as a result of the fall of an asteroid with a diameter of 1-3 km into a sea with a depth of 300-500 m. This happened 142 million years ago. An asteroid at a distance of 1 thousand km caused a tsunami with a height of 100-200 m;

Lokne crater in Sweden. It was formed about 450 million years ago by the fall of an asteroid about 600 m in diameter into a sea 0.5-1 km deep. The cosmic body caused a wave with a height of 40-50 m at a distance of about 1 thousand km;

Eltanin crater. It is located at a depth of 4-5 km. It arose as a result of the fall of an asteroid 0.5-2 km in diameter 2.2 million years ago, which led to the formation of a tsunami with a height of about 200 m at a distance of 1 thousand km from the epicenter.

Naturally, the height of the tsunami waves near the coast was much higher.

In total, about 20 craters have been discovered in the world's oceans.

Natural disasters of our time

Now there is no doubt that the past century was marked by a rapid increase in the number of natural disasters and the volume of material losses associated with them and physical and geographical changes in territories. In less than half a century, the number of natural disasters has tripled. The increase in the number of disasters occurs mainly due to atmospheric and hydrospheric hazards, which include floods, hurricanes, tornadoes, storms, etc. The average number of tsunamis remains almost unchanged - about 30 per year. Apparently, these events are associated with a number of objective reasons: population growth, growth in energy production and its release, changes in environment, weather and climate. It is proved that the air temperature over the past few decades has increased by about 0.5 degrees Celsius. This led to an increase in the internal energy of the atmosphere by about 2.6 1021 J, which is tens and hundreds of times higher than the energy of the strongest cyclones, hurricanes, volcanic eruptions and thousands and hundreds of thousands of times the energy of earthquakes and their consequences - tsunamis. It is possible that the increase in the internal energy of the atmosphere destabilizes the metastable ocean-land-atmosphere (OSA) system responsible for the weather and climate on the planet. If so, then it is quite possible that many natural disasters are related.

The idea that the growth of natural anomalies is generated by a complex anthropogenic impact on the biosphere was put forward in the first half of the 20th century by the Russian researcher Vladimir Vernadsky. He believed that the physical and geographical conditions on Earth in general plan immutable and owe the functioning of the living. However, human economic activity disturbs the balance of the biosphere. As a result of deforestation, plowing of territories, drainage of swamps, urbanization, the surface of the Earth, its reflectivity is changing, and the natural environment is being polluted. This leads to a change in the trajectories of heat and moisture transfer in the biosphere and, ultimately, to the appearance of undesirable natural anomalies. Such a complex degradation of the natural environment is the cause of natural disasters leading to global geophysical changes.

The historical genesis of the earth's civilization is organically woven into the global context of the evolution of nature, which has a cyclical nature. It has been established that the geographical, historical and social phenomena taking place on the planet do not occur sporadically and arbitrarily, they are in organic unity with certain physical phenomena of the surrounding world.

From a metaphysical point of view, the nature and content of the evolution of all life on Earth is determined by the regular change of historical and metrical cycles of sunspot-forming activity. At the same time, the cycle change is accompanied by all sorts of cataclysms - geophysical, biological, social and others.

Thus, the metaphysical measurement of the fundamental qualities of space and time makes it possible to track and identify the most serious threats and dangers to the existence of earthly civilization in different periods development of world history. Based on the fact that the safe paths of evolution of the earth's civilization are organically linked with the stability of the planet's biosphere as a whole and the mutual conditionality of the existence of all biological species in it, it is important not only to understand the nature of natural and climatic anomalies and cataclysms, but also to see the ways of salvation and survival of mankind .

According to existing forecasts, in the foreseeable future there will be another change in the global historical and metrical cycle. As a result, humanity will face cardinal geophysical changes on planet Earth. According to experts, natural and climatic cataclysms will lead to a change in the geographical configuration of individual countries, shifts in the state of the habitat and ethnic landscapes. Flooding of vast territories, an increase in the area of ​​marine areas, soil erosion, an increase in the number of lifeless spaces (deserts, etc.) will become common phenomena. Changes in environmental conditions, in particular the length of daylight hours, precipitation characteristics, the state of the ethno-nurturing landscape, etc., will actively influence the characteristics of biochemical metabolism, the formation of the subconscious and the mentality of people.

Analysis of the probable physical and geographical causes of powerful floods in Europe in last years(in Germany, as well as in Switzerland, Austria and Romania) conducted by a number of scientists, shows that the primary cause of destructive cataclysms is, most likely, the release from the ice of the Arctic Ocean.

In other words, due to the ongoing sharp warming of the climate, it is quite possible that floods are just beginning. The amount of open blue water in the straits between the Arctic islands of the Great Canadian Archipelago has increased. Giant polynyas appeared even between the northernmost of them - Ellesmere Island and Greenland.

Release from multi-year, heavy landfast ice, with which the aforementioned straits between these islands were literally clogged before, can lead to a sharp increase in the so-called Western flow of cold Arctic water into the Atlantic (with a temperature of minus 1.8 degrees Celsius) from west side Greenland. And this, in turn, will sharply reduce the cooling of this water, which is still flowing in bulk from the eastern side of Greenland, which is moving towards it from the Gulf Stream. The Gulf Stream in the future can be cooled by this runoff by 8 degrees Celsius. At the same time, American scientists predicted a catastrophe if the water temperature in the Arctic rises even by one degree Celsius. Well, if it rises by a few degrees, then the ice covering the ocean will melt not in 70-80 years, as American scientists predict, but in less than ten.

According to experts, in the foreseeable future, coastal countries whose territories are directly adjacent to the waters of the Pacific, Atlantic and Arctic oceans will be in a vulnerable position. Members of the Intergovernmental Panel on Climate Change believe that due to the active melting of the glaciers of Antarctica and Greenland, the level of the World Ocean may rise by 60 cm, which will lead to the flooding of some island states and coastal cities. First of all, we are talking about the territories of the North and Latin America, Western Europe, Southeast Asia.

Such assessments are contained not only in open scientific articles, but also in closed studies of special government agencies in the US and Great Britain. In particular, according to Pentagon estimates, if in the next 20 years there will be problems with temperature regime Gulf Stream in the Atlantic, this will inevitably change the physical and geographical position of the continents, a global crisis of the world economy will come, which will lead to new wars and conflicts in the world.

According to the studies, on the planet the greatest resistance to natural disasters and anomalies, due to its physical and geographical data, will continue to be preserved by the Eurasian continent, the post-Soviet space and, above all, the modern territory of the Russian Federation.

We are talking here about what is happening, according to scientists, the movement of the energy center of the Sun to a “large physical and geographical zone” from the Carpathians to the Urals. Geographically, it coincides with the lands of "historical Russia", which usually include the modern territories of Belarus and Ukraine, the European part of Russia. The action of such phenomena of cosmic origin means a point concentration of solar and other energy on the fauna and flora of the “large physical-geographical zone”. In a metaphysical context, a situation arises in which the area of ​​settlement of the peoples of this territory will play a major role in world social processes.

not so long ago there was a sea

At the same time, according to existing geological estimates, the physical and geographical position of Russia, unlike many other countries, will suffer to a lesser extent from the catastrophic consequences of natural changes on Earth. It is expected that the general warming of the climate will contribute to the regeneration of the natural and climatic habitat, an increase in the diversity of fauna and flora in certain areas of Russia. Global changes will have a beneficial effect on the fertility of the lands of the Urals and Siberia. At the same time, experts suggest that the territory of Russia is unlikely to escape large and small floods, the growth of steppe zones and semi-deserts.

CONCLUSION

Throughout the history of the Earth, the physical and geographical position of all elements of the land has changed under the influence of natural disasters.

A change in the factors of the physical and geographical position can occur, as a rule, only under the influence of natural disasters.

The largest geophysical disasters associated with numerous casualties and destruction, changes in the physical and geographical data of territories, are caused as a result of seismic activity of the lithosphere, which most often manifests itself in the form of earthquakes. Earthquakes provoke other natural disasters: volcanic activity, tsunamis, floods. A real megatsunami occurred when space bodies with dimensions from tens of meters to tens of kilometers fell into the ocean or sea. Such events in the history of the Earth happened many times.

Many specialists of our time recognize an obvious trend towards an increase in the number of natural anomalies and disasters, the number of natural disasters per unit of time continues to grow. Perhaps this is due to the deterioration of the ecological situation on the planet, with an increase in the temperature of gas in the atmosphere.

According to experts, due to the melting of the Arctic glaciers, new severe floods await the northern continents in the very near future.

Evidence of the reliability of geological forecasts are all sorts of natural disasters that have occurred recently. Today, natural anomalous phenomena, temporary climatic imbalances, sharp temperature fluctuations are becoming constant companions of our lives. They increasingly destabilize the situation and make significant adjustments to the daily life of the states and peoples of the world.

The situation is aggravated by the growing influence anthropogenic factor on the state of the environment.

In general, the upcoming natural, climatic and geophysical changes, which carry a serious threat to the very existence of the peoples of the world, require states and governments to be ready to act in crisis conditions today. The world is gradually beginning to realize that the problems of the vulnerability of the current ecological system of the Earth and the Sun have acquired the rank of global threats and require immediate resolution. According to scientists, humanity is still able to cope with the consequences of natural and climatic changes.

An avalanche is a huge mass of snow that periodically falls in the form of landslides and avalanches from steep ridges and slopes of high snowy mountains. Avalanches usually move along the weathering ruts existing on the slopes of the mountains, and in the place where their movement stops, in river valleys and at the foot of the mountains, they deposit snow piles, known as avalanche cones.

In addition to occasional glaciers and hail avalanches, periodic winter and spring avalanches are distinguished. Winter avalanches occur due to the fact that freshly fallen loose snow, leaning on the icy surface of old snow, slides over it and rolls down in masses on steep slopes from insignificant causes, often from a shot, a scream, a gust of wind, etc.

The gusts of wind caused by the rapid movement of the snow mass are so strong that they break trees, rip off roofs and even destroy buildings. Spring avalanches are caused by melting water breaking the bond between soil and snow cover. The snow mass on steeper slopes breaks off and rolls down, capturing in its movement stones, trees and buildings encountered on the way, which is accompanied by a strong rumble and crackling.

The place from which such an avalanche rolled down is in the form of a bare black clearing, and where the avalanche stops moving, an avalanche cone is formed, which has a loose surface at first. In Switzerland, avalanches are a common occurrence and have been the subject of repeated observations. The mass of snow delivered by individual avalanches sometimes reaches 1 million or even more m³.

Avalanches, except for the Alps, were observed in the Himalayan mountains, Tien Shan, in the Caucasus, in Scandinavia, where avalanches breaking down from mountain peaks sometimes reach fiords, in the Cordillera and other mountains.

Sel (from the Arabic "sail" - "stormy stream") is a water, stone or mud stream that occurs in the mountains when rivers overflow, snow melts or after a large amount of precipitation. Similar conditions are typical for most mountainous regions.

According to the composition of the mudflow mass, mudflows are divided into mud-stone, mud, water-stone and water-dressing, and according to physical types - disconnected and connected. In non-cohesive mudflows, the transport medium for solid inclusions is water, and in coherent mudflows, a water-ground mixture. Mudflows move along the slopes at a speed of up to 10 m/s or more, and the mass volume reaches hundreds of thousands, and sometimes millions of cubic meters, and the mass is 100-200 tons.

Mudflows sweep away everything in their path: they destroy roads, buildings, etc. To combat mudflows on the most dangerous slopes, special structures are installed and a vegetation cover is created that holds the soil layer on the mountain slopes.

In ancient times, the inhabitants of the Earth could not find true reason this event, therefore, they associated the volcanic eruption with the disfavor of the gods. Eruptions often caused the death of entire cities. So, at the very beginning of our era, during the eruption of Mount Vesuvius, one of the greatest cities of the Roman Empire, Pompeii, was wiped off the face of the earth. The ancient Romans called the god of fire a volcano.

Volcanic eruption is often preceded by an earthquake. In time, in addition to lava, hot stones, gases, water vapor, and ash fly out of the crater, the height of which can reach 5 km. But the greatest danger to people is precisely the eruption of lava, which melts even stones and destroys all life in its path. During one eruption, up to several km³ of lava is ejected from the volcano. But a volcanic eruption is not always accompanied by a lava flow. Volcanoes can be dormant for many years, and the eruption lasts from several days to several months.

Volcanoes are divided into active and extinct. Active volcanoes are those whose last eruption is known. Some volcanoes last erupted so long ago that no one remembers it. Such volcanoes are called extinct. Volcanoes that erupt every few thousand years are called potentially active. If in total there are about 4 thousand volcanoes on Earth, of which 1340 are potentially active.

In the earth's crust, which is under the cover of the sea or ocean, the same processes take place as on the mainland. Lithospheric plates collide, causing tremors in the earth's crust. There are active volcanoes at the bottom of the seas and oceans. It is as a result of underwater earthquakes and volcanic eruptions that huge waves are formed, which are called tsunamis. This word is translated from Japanese language means "giant wave in the harbour".

As a result of the shaking of the ocean floor, a huge column of water sets in motion. The farther from the epicenter of the earthquake the wave moves, the higher it becomes. As the wave approaches land, the lower layers of water hit the bottom, further increasing the power of the tsunami.

The height of a tsunami is usually 10-30 meters. When such a huge mass of water, moving at speeds up to 800 km/h, hits the shore, nothing living is able to survive. The wave sweeps away everything in its path, after which it picks up fragments of destroyed objects and throws them deep into the island or mainland. Usually, the first won is followed by several more (from 3 to 10). Waves 3 and 4 are usually the strongest.

One of the most destructive tsunamis hit the Commander Islands in 1737. According to experts, the wave height was more than 50 meters. Only a tsunami of such power could throw so far on the island the inhabitants of the ocean, whose remains were found by scientists.

Another major tsunami occurred in 1883 after the eruption of the Krakatau volcano. Because of this, a small uninhabited island, on which Krakatoa was located, fell into the water to a depth of 200 meters. The wave that reached the islands of Java and Sumatra reached 40 meters in height. As a result of this tsunami, about 35 thousand people died.

Tsunamis do not always have such dire consequences. Sometimes giant waves do not reach the shores of continents or islands inhabited by people and remain practically unnoticed. AT open ocean, before impact with the shore, the height of the tsunami does not exceed one meter, so for ships far from the coast it does not

An earthquake is a strong vibration of the earth's surface caused by processes occurring in the lithosphere. Most earthquakes occur near high mountains, since these areas still continue to form and the earth's crust here is especially mobile.

Earthquakes are of several types: tectonic, volcanic and landslide. Tectonic earthquakes occur when mountain plates are displaced or as a result of collisions between oceanic and continental platforms. During such collisions, mountains or depressions are formed and the surface oscillates.

Volcanic earthquakes occur when flows of hot lava and gases press down on the surface of the Earth. Volcanic earthquakes are usually not too strong, but can last up to several weeks. In addition, volcanic earthquakes are usually the forerunners of a volcanic eruption, which threatens with more serious consequences.

Landslide earthquakes are associated with the formation of underground voids that occur under the influence of ground water or underground rivers. At the same time, the top layer of the earth's surface collapses down, causing small shaking.

The place where an earthquake occurs (collision of plates) is called its source or hypocenter. The area of ​​the earth's surface where an earthquake occurs is called the epicenter. It is here that the most severe destruction occurs.

The strength of earthquakes is determined on a ten-point Richter scale, depending on the amplitude of the wave that occurs during the vibration of the surface. The larger the amplitude, the stronger the earthquake. The weakest earthquakes (1-4 points on the Richter scale) are recorded only by special sensitive instruments and do not cause damage. Sometimes they manifest themselves in the form of glass trembling or moving objects, and sometimes they are completely invisible. Earthquakes of 5-7 on the Richter scale cause minor damage, and stronger ones can cause complete destruction of buildings.

Seismologists study earthquakes. According to them, about 500,000 earthquakes of various strengths occur on our planet every year. About 100 thousand of them are felt by people, and 1000 cause damage.

Floods are one of the most common natural disasters. They make up 19% of total number natural disasters. Flooding is the flooding of land that occurs as a result of a strong rise in the water level in a river, lake or sea (spill), due to the melting of snow or ice, as well as heavy and prolonged rains.

Depending on the cause of the flood, they are divided into 5 types:

High water - a flood that occurs as a result of melting snow and the release of a reservoir from its natural banks

Flood - a flood associated with heavy rains

Flooding caused by large accumulations of ice that clog the riverbed and prevent water from flowing downstream

Floods caused by strong winds that push water in one direction, most often against the current

Floods resulting from a dam or reservoir failure.

Floods and floods occur every year wherever there are full-flowing rivers and lakes. They are usually expected, they heat up relatively large area and do not lead to the death of a large number of people, although they cause destruction. If these types of floods are accompanied by heavy rains, then a much larger area is already flooded. Usually, as a result of such floods, only small buildings are destroyed without a reinforced foundation, communication and power supply are disrupted. The main inconvenience is the flooding of the lower floors of buildings and roads, as a result of which the inhabitants of the flooded areas remain cut off from land.

In some areas where floods are most frequent, houses are even raised on special piles. Floods resulting from the destruction of dams have a great destructive power, especially since they occur unexpectedly.

One of the most severe floods occurred in 2000 in Australia. Heavy rain did not stop there for two weeks, as a result of which 12 rivers immediately overflowed their banks and flooded an area of ​​200 thousand km².

To prevent floods and their consequences during the floods, the ice on the rivers is blown up, breaking it into small ice floes that do not prevent the flow of water. If a large amount of snow falls during the winter, which threatens with a strong flood of the river, residents from dangerous areas are evacuated in advance.

Hurricane and tornado are atmospheric vortices. However, these two natural phenomena are formed and manifest themselves in different ways. A hurricane is accompanied by a strong wind, and a tornado occurs in thunderclouds and is an air funnel that sweeps away everything in its path.

The speed of a hurricane wind on Earth is 200 km/h near the earth. This is one of the most destructive phenomena of nature: passing over the surface of the earth, it uproots trees, rips off the roofs of houses, and brings down the supports of power lines and communications. A hurricane can exist for several days, weakening and then gaining strength again. The danger of a hurricane is assessed on a special five-point scale, which was adopted in the last century. The degree of danger depends on the speed of the wind and on the destruction that the hurricane produces. But terrestrial hurricanes are far from the strongest. On the giant planets (Jupiter, Saturn, Uranus, Neptune), hurricane wind speeds reach 2000 km/h.

A tornado is formed when moving unevenly heated layers of air. It spreads in the form of a dark sleeve towards the land (funnel). The height of the funnel can reach 1500 meters. The funnel of the tornado twists from the bottom up counterclockwise, sucking in everything that is next to it. It is because of the dust and water captured from the ground that the tornado acquires a dark color and becomes visible from afar.

The speed of the tornado can reach 20 m/s, and the diameter can be up to several hundred meters. Its strength allows uprooted trees, cars and even small buildings to be lifted into the air. A tornado can occur not only over land, but also over the water surface.

The height of a spinning air column can reach a kilometer and even one and a half kilometers, it moves at a speed of 10-20 m / s. Its diameter can be from 10 meters (if the tornado passes over the ocean) to several hundred meters (if it passes over the ground). Often a tornado is accompanied by a thunderstorm, rain or even hail. It exists much less than a hurricane (only 1.5-2 hours) and is able to travel only 40-60 km.
The most frequent and strong tornadoes occur on the west coast of America. Americans even assign human names to the largest natural disasters (Katrina, Denis). A tornado in America is called a tornado.

Natural disasters and cataclysms always cause huge damage to a person., both physical (fatal outcome) and moral (experiences and fear). As a result, terrible malware natural phenomena(such as tsunamis, tornadoes and tornadoes, floods, hurricanes, storms, etc.) are becoming an increasing threat to people.

Term - natural disasters - applied to two different concepts, which are in some sense interlocking. Catastrophe in literal translation means - a turn, a restructuring. This value corresponds to the most general idea of ​​catastrophes in natural science, where the evolution of the Earth is seen as a series of different catastrophes that cause a change in geological processes and types of living organisms.

Also the concept - natural disasters refers only to extreme natural phenomena and processes resulting in loss of life. In this understanding - natural disasters opposed - technogenic disasters, i.e. those caused directly by human activity.

Natural disaster is an event caused by natural causes, the destructive effect of which manifests itself within a fairly wide spatio-temporal parameters and causes the death and / or injury of people, as well as significant temporary or permanent changes in the living communities that it affects. It also causes significant material damage due to the adverse impact on human activities and biological resources.

Global natural disasters can be called both very large, but not fatal for mankind catastrophes, and those that lead to the extinction of mankind.

Natural disasters in the generally accepted sense have always been one of the elements of global ecodynamics. Natural disasters and various natural cataclysms in the past occurred in accordance with the development of natural natural trends, and since the 19th century, anthropogenic factors began to influence their dynamics. The deployment of engineering activities in the 20th century and the formation of a complex socio-economic structure of the world not only dramatically increased the proportion of anthropogenic natural disasters, but also changed the characteristics of the environment, giving them dynamics in the direction of worsening the habitat of living beings, including humans.

Every year, the number of natural disasters in the world increases, on average, by about 20 percent. Such a disappointing conclusion was made by specialists of the International Federation of the Red Cross and Red Crescent Society.

For example, in 2006 there were 427 natural disasters in the world. Most of the deaths were recorded as a result of earthquakes, tsunamis, and floods. Over the past 10 years, the death rate in disasters has increased from 600 thousand to 1.2 million people a year, and the number of victims has increased from 230 to 270 million.

Some catastrophes occur under the earth's surface, others - on it, others - in the water shell (hydrosphere), and the last in the air shell (atmosphere) of the Earth.

Earthquakes and volcanic eruptions, acting from below on the earth's surface, lead to surface catastrophes, such as landslides or tsunamis, as well as fires. Other surface catastrophes occur under the influence of processes in the atmosphere, where temperature and pressure drops are equalized and energy is transferred to the water surface.

As with all natural processes, natural disasters are interconnected. One catastrophe affects another, it happens that the first catastrophe serves as a trigger for subsequent ones.

The closest relationship exists between earthquakes and tsunamis, volcanic eruptions and fires. Tropical cyclones almost always cause flooding. Earthquakes can also cause landslides. Those, in turn, can block river valleys and cause floods. There is a mutual relationship between earthquakes and volcanic eruptions: earthquakes caused by volcanic eruptions are known, and, conversely, volcanic eruptions caused by the rapid movement of masses under the Earth's surface. Tropical cyclones can be a direct cause of both river and sea flooding. Atmospheric disturbances and heavy rainfall can affect slope creep.

Earthquakes are underground shocks and vibrations of the Earth's surface caused by natural causes (mainly tectonic processes). In some places on the Earth, earthquakes occur frequently and sometimes reach great strength, breaking the integrity of the soil, destroying buildings and causing loss of life.

The number of earthquakes recorded annually on the globe is in the hundreds of thousands. However, the vast majority of them are weak, and only a small proportion reaches the degree of catastrophe.

The area of ​​occurrence of an underground impact - the focus of an earthquake - is a certain volume in the thickness of the Earth, within which the process of releasing energy accumulated for a long time takes place. In a geological sense, a focus is a gap or a group of gaps along which an almost instantaneous movement of masses occurs. In the center of the focus, a point is conventionally distinguished, called the hypocenter. The projection of the hypocenter onto the Earth's surface is called the epicenter. Around it is the region of the greatest destruction - the pleistoseist region. Lines connecting points with the same vibration intensity (in points) are called isoseists.

Seismic waves are recorded using instruments called seismographs. Nowadays, they are very complex electronic devices that make it possible to capture the weakest vibrations of the earth's surface.

There is a need for a simple and objective determination of the magnitude of earthquakes, and with the help of such a measure that could be easily calculated and freely compared. This kind of scale was proposed by the Japanese scientist Wadachi in 1931. In 1935, it was improved by the famous American seismologist C. Richter. Such an objective measure of the magnitude of earthquakes is the magnitude, denoted by M.

The characteristic of the earthquake strength depending on the value of M can be presented in the form of a table:

Richter scale characterizing the magnitude of earthquakes

	Characteristic
	The weakest earthquake that can be recorded using instruments
	Felt near the epicenter. About 100,000 such earthquakes are recorded annually.
	Minor damage may be observed near the epicenter
	Approximately equivalent to the energy of one atomic bomb
	In a limited area can cause significant damage. Annually such there are about 100 earthquakes
	From this level, earthquakes are considered strong

The Great Chilean earthquake (or the Valdivian earthquake) is the strongest earthquake in the history of observation, its magnitude, according to various estimates, was from 9.3 to 9.5. The earthquake occurred on May 22, 1960, its epicenter was located near the city of Valdivia, 435 kilometers south of Santiago.

The tremors caused a powerful tsunami, the wave height of which reached 10 meters. The number of victims was about 6 thousand people, and the main part of the people died precisely from the tsunami. Huge waves caused severe damage around the world, killing 138 people in Japan, 61 people in Hawaii and 32 in the Philippines. The damage in 1960 prices amounted to about half a billion dollars.

On March 11, 2011, an earthquake of magnitude 9.0 on the Richter scale struck east of Honshu Island. This earthquake is considered the most powerful in the entire known history of Japan.

Tremors caused the strongest tsunami (up to 7 meters in height), which killed about 16 thousand people. Moreover, the earthquake and tsunami impact were the cause of the accident at the Fukushima-1 nuclear power plant. Total damage from natural disaster is estimated at $14.5-$36.6 billion.

North Sumatra, Indonesia, 2004 - magnitude 9.1-9.3

An undersea earthquake in the Indian Ocean on 26 December 2004 triggered a tsunami that has been recognized as the deadliest natural disaster in modern history. The magnitude of the earthquake was, according to various estimates, from 9.1 to 9.3. This is the third strongest earthquake in the history of observation.

The epicenter of the earthquake was located not far from the Indonesian island of Sumatra. The earthquake triggered one of the most destructive tsunamis in history. The height of the waves exceeded 15 meters, they reached the shores of Indonesia, Sri Lanka, southern India, Thailand and a number of other countries.

The tsunami almost completely destroyed the coastal infrastructure in the east of Sri Lanka and the northwestern coast of Indonesia. Died, according to various estimates, from 225 thousand to 300 thousand people. The damage from the tsunami amounted to about $10 billion.

Tsunami (Japanese) - marine gravity waves of very large length, resulting from the upward or downward displacement of extended sections of the bottom during strong underwater and coastal earthquakes and, occasionally, due to volcanic eruptions and other tectonic processes. Due to the low compressibility of water and the speed of the process of deformation of the bottom sections, the water column resting on them also shifts without having time to spread, as a result of which a certain elevation or depression forms on the ocean surface. The resulting perturbation turns into oscillatory movements of the water column - tsunami waves propagating at high speed (from 50 to 1000 km / h). The distance between neighboring wave crests varies from 5 to 1500 km. The height of the waves in the area of ​​their occurrence varies between 0.01-5 m. Near the coast, it can reach 10 m, and in unfavorable relief areas (wedge-shaped bays, river valleys, etc.) - over 50 m.

About 1000 cases of tsunamis are known, of which more than 100 had catastrophic consequences, which caused complete destruction, washing away of structures and soil and vegetation cover. 80% of tsunamis occur on the periphery of the Pacific Ocean, including the western slope of the Kuril-Kamchatka Trench. Based on the patterns of occurrence and spread of tsunamis, the zoning of the coast is carried out according to the degree of threat. Measures for partial protection against tsunamis: creation of artificial coastal structures (breakwaters, breakwaters and embankments), planting forest strips along the ocean coast

Flooding - significant flooding of the area with water as a result of a rise in the water level in a river, lake or sea, caused by various reasons. Flooding on the river occurs from a sharp increase in the amount of water due to the melting of snow or glaciers located in its basin, as well as as a result of heavy precipitation. Flooding is often caused by an increase in the water level in the river due to blockage of the channel by ice during ice drift (jam) or due to clogging of the channel under the immovable ice cover by accumulations of intra-water ice and the formation of an ice plug (jam). Floods often occur under the influence of winds that bring water from the sea and cause an increase in the level due to the delay at the mouth of the water brought by the river.

Petersburg flood, 1824, about 200-600 dead. On November 19, 1824, a flood occurred in St. Petersburg, which killed hundreds human lives and destroyed many houses. Then the water level in the Neva River and its canals rose by 4.14 - 4.21 meters above the usual level (ordinary).

Flood in China, 1931, about 145 thousand - 4 million dead. From 1928 to 1930, China suffered from a severe drought. But at the end of the winter of 1930, heavy snowstorms began, and in the spring - incessant heavy rains and thaw, due to which the water level in the Yangtze and Huaihe rivers rose significantly. For example, in the Yangtze River only in July, the water rose by 70 cm. As a result, the river overflowed its banks and soon reached the city of Nanjing, which was then the capital of China. Many people drowned and died from water-borne infectious diseases such as cholera and typhoid. Cases of cannibalism and infanticide among desperate residents are known. According to Chinese sources, about 145 thousand people died as a result of the flood, while Western sources claim that the death toll was from 3.7 million to 4 million.

Landslides - sliding displacement of masses rocks downhill under the influence of gravity. Landslides occur in any part of a slope or slope due to an imbalance in rocks caused by: an increase in the steepness of the slope as a result of water washing; weakening of the strength of rocks during weathering or waterlogging by precipitation and groundwater; the impact of seismic shocks; construction and economic activities carried out without taking into account the geological conditions of the area (destruction of slopes by road cuts, excessive watering of gardens and vegetable gardens located on slopes, etc.). Most often, landslides occur on slopes composed of alternating water-resistant (clay) and water-bearing rocks (for example, sand and gravel, fractured limestone). The development of a landslide is facilitated by such an occurrence when the layers are located with an inclination towards the slope or are crossed by cracks in the same direction. In highly moistened clay rocks, landslides take the form of a stream.

Landslide in Southern California in 2005. Powerful downpours that hit Southern California and the resulting floods, mudflows and landslides have claimed the lives of more than 20 people.

South Korea - August 2011

59 people died. 10 are listed as missing.

Heavy rainfall, which was observed to be the heaviest in recent times.

Volcanoes (named after the god of fire Vulcan), geological formations that arise above channels and cracks in the earth's crust, through which lava, hot gases and rock fragments erupt onto the earth's surface from deep magmatic sources. Volcanoes usually represent individual mountains composed of eruptions.

Volcanoes are divided into active, dormant and extinct. The former include: those that are currently erupting constantly or periodically; about the eruptions of which there are historical data; about the eruptions of which there is no information, but which emit hot gases and water (solfatar stage). Dormant volcanoes are those whose eruptions are not known, but they have retained their shape and local earthquakes occur under them. Extinct volcanoes are called heavily destroyed and eroded volcanoes without any manifestations of volcanic activity.

Eruptions are long-term (for several years, decades and centuries) and short-term (measured by hours).

An eruption usually begins with an increase in gas emissions, first along with dark, cold lava fragments, and then with red-hot ones. These emissions are in some cases accompanied by an outpouring of lava. The height of the rise of gases, water vapor, saturated with ash and lava fragments, depending on the strength of the explosions, ranges from 1 to 5 km (during the Bezymyanny eruption in Kamchatka in 1956, it reached 45 km). The ejected material is transported over distances from several to tens of thousands of kilometers. The volume of ejected clastic material sometimes reaches several km3.

During some eruptions, the concentration of volcanic ash in the atmosphere is so great that there is darkness, similar to darkness in an enclosed space. This took place in 1956 in the village of Klyuchi, located 40 km from V. Bezymyanny.

The products of volcanic eruptions are gaseous (volcanic gases), liquid (Lava) and solid (volcanic rocks).

Modern volcanoes are located along young mountain ranges or along large faults (grabens) for hundreds and thousands of kilometers in tectonically mobile areas (see table). Almost two-thirds of the volcanoes are concentrated on the islands and shores of the Pacific Ocean (Pacific volcanic belt). The Atlantic Ocean region stands out from other regions in terms of the number of active volcanoes.

Vesuvius, 79 AD

During the eruption, Vesuvius threw a deadly cloud of ash and smoke to a height of 20.5 km, and every second erupted about 1.5 million tons of molten rock and crushed pumice. At the same time, a huge amount of thermal energy was released, which many times exceeded the amount released during the explosion of the atomic bomb over Hiroshima.

Tornadoes are catastrophic atmospheric vortices having the shape of a funnel with a diameter of 10 to 1 km. In this vortex, the wind speed can reach an incredible value - 300 m / s (which is more than 1000 km / h).

The forward speed of a tornado is 40 km / h, which means that you can’t run away from it, you can only leave by car. Escape from a tornado, however, is also problematic in this case, since its route is absolutely irregular and unpredictable.

A tornado is somewhat reminiscent of a cyclone, for example, in its circular whirling of air or in the fact that there is low pressure in the center of the funnel.

In the deserts of the United States, there are two types of eddy winds - classic tornadoes and the so-called "desert devils". Tornadoes are associated with thunderclouds, while inverted "desert devil" funnels are not associated with cloud formations.

The origin of a tornado is not completely understood. Obviously, they are formed at moments of unstable air stratification, when the heating of the earth's surface leads to heating of the lower layer of air as well. Above this layer there is a layer of colder air, this situation is unstable. Warm air rushes up, while cold air in a whirlwind, like a trunk, descends down to the earth's surface. Often this occurs over small, elevated areas within flat terrain.

There is a scale, similar to those used to determine the intensity of earthquakes or the strength of the wind, which determines the strength of a tornado.

Strong tornadoes leave a strip of devastated land behind them. Roofs are torn off houses, trees are uprooted from the ground, people and cars are lifted into the air. When the path of a tornado runs through a densely populated area, the number of victims reaches a significant value. So, on April 11, 1965, 37 tornadoes arose over the territory of the Midwest of the United States, which caused the death of 270 people. Tornadoes are most frequently reported in the United States of America.

Statistics on the number of victims of tornadoes are inaccurate. Over the past 50 years, up to 30 people have died from them annually in the United States alone.

Tornado protection is problematic. They appear unexpectedly. It is impossible to determine their trajectory. The transmission of warnings by telephone from city to city can help. The best and, apparently, the only defense against a tornado is to take cover in the basement or in a solid building.

Oklahoma 2013. According to scientists, the speed of EF5-type vortices is more than 322 kilometers per hour (89 meters per second). The width of the tornado was two kilometers, duration - 40 minutes. According to meteorologists, less than one percent of all tornadoes in the United States reach such a force, that is, about ten tornadoes per year. Previously, experts tentatively rated Oklahoma tornado power one point lower, that is, four points out of five on the improved Fujita scale.

About 24 dead. 237 people suffered.

Legends of different peoples of the world tell of a certain ancient catastrophe that has befallen our planet. It was accompanied by terrible floods, earthquakes, volcanic eruptions; the lands were depopulated, and part of the land sank to the bottom of the sea ...

An avalanche of environmental, social and man-made disasters hit us at the start of the 21st century. Daily messages from all over the world announce new cataclysms of nature: eruptions, earthquakes, tsunamis, tornadoes and forest fires. But not harbingers whether it global catastrophe of the earth, because it seems that the next event will become even more destructive, take even more lives.

Nature of our planet, united in the four elements, as if warning a person: stop! Change your mind! Otherwise you with my own hands organize a terrible judgment for yourself ...

Fire

Volcanic eruptions. Earth engulfed by fiery belts of volcanoes. There are four belts in total. The largest is the Pacific Ring of Fire, which has 526 volcanoes. Of these, 328 erupted in a historically foreseeable time.

Fires. So disastrous in its consequences cataclysm of nature, like a fire (forest, peat, grass and household), causes enormous damage to the economy Earth claiming hundreds of human lives. According to the World Health Organization, hundreds of deaths each year are caused by the health effects of smoke from forest and peat fires. Smoke also provokes traffic accidents.

Earth

Earthquakes. Tremors and vibrations of the planet's surface, caused by tectonic processes, occur annually throughout Earth, their number reaches a million, but most are so insignificant that they go unnoticed. happen on the planet about once every two weeks.

Sliding solid. It just so happened that a man called himself the owner nature. But sometimes it seems that she only tolerates such self-appointment, at a certain moment making it clear who is the boss in the house. Her anger is sometimes terrible. Landslides, mudflows and avalanches - slipping of the soil, the descent of snow masses or streams of water carrying fragments of rocks and clay - these sweep away everything in their path.

Water

Tsunami. The nightmare of all the inhabitants of the ocean coast - a giant tsunami wave - arises from an underwater earthquake. The shock causes a fault on the seabed, along which significant sections of the bottom rise or fall, which leads to the growth of a multi-kilometer column of water. A tsunami appears, carrying billions of tons of water. Colossal energy drives it to a distance of 10-15 thousand km. Waves follow each other with an interval of about 10 minutes, propagating at a speed jet aircraft. In the deepest parts of the Pacific Ocean, their speed reaches 1000 km / h.

Floods. A furious torrent of water can demolish entire cities, leaving no one a chance to survive. The reason most often is a sharp rise in water to a critical level after prolonged downpours.

Droughts. Who doesn't love the sun? Its gentle rays cheer up and bring the world back to life after hibernation ... But it happens that the abundant sun causes the death of crops, animals and people, provokes fires. Drought is one of the most dangerous natural disasters.

Air

Typhoon or hurricane. Atmosphere Earth never calm, its air masses are in constant motion. Under the influence of solar radiation, relief and daily rotation of the planet, inhomogeneities arise in the air ocean. Areas of low pressure are called cyclones, and areas of high pressure are called anticyclones. It is in cyclones that strong winds. The largest of them reach thousands of kilometers in diameter and are clearly visible from space thanks to the clouds that fill them. In fact, these are vortices where the air moves in a spiral from the edges to the center. Such whirlwinds, constantly existing in the atmosphere, but born in the tropics - the Atlantic and the eastern part of the Pacific Ocean and reaching wind speeds of more than 30 m / s, are called hurricanes. Most often, hurricanes originate over heated areas of the tropical zones of the oceans, but they can also occur at high latitudes near the poles. Earth. Similar phenomena in the western part of the Pacific Ocean north of the equator are called typhoons (from the Chinese "tifeng", which means "big wind"). The most high-speed whirlwinds that arise in thunderclouds are tornadoes.

Tornado, or tornado. An air funnel that stretches from a thundercloud to the ground is one of the most powerful and destructive phenomena- natural disasters. Tornadoes (they are also tornadoes) occur in the warm sector of a cyclone, when warm air currents collide under the influence of a strong side wind. Quite unexpectedly, the beginning of this natural disaster can be ordinary rain. The temperature drops sharply, a whirlwind appears due to rain clouds and rushes at great speed. It rolls with a deafening roar, drawing in everything that comes in its way: people, cars, houses, trees. The power of a tornado is devastating, and the consequences are terrible.

Climate change. Global climate change does not give a rest to meteorologists or mere mortals. Forecasters continue to mark temperature records, while constantly making mistakes in forecasts even for the coming days. The current warming is a natural way out of the Little Ice Age of the XIV-XIX centuries.

Who is to blame for cataclysms of nature?

To a large extent, the warming observed over the past 50-70 years is caused by human activities, primarily the emission of gases that cause the greenhouse effect. Glaciers are melting, sea levels are rising. This is what leads to natural disasters: hotter summer, more Cold winter, floods, hurricanes, droughts, extinction of entire species of flora and fauna. But isn't it getting ready? nature take revenge on a person global catastrophe of the earth?

According to the materials of the magazine "World of Secrets and Mysteries", No. 4, 2012

In this article, we will consider some changes in the physical and geographical state of nature that occur on earth under the influence of cataclysms. Every locality has its own individual position, and unique. And any physical-geographical change in it usually leads to corresponding consequences in the areas adjacent to it.

Some catastrophes and cataclysms will be briefly described here.

Definition of a cataclysm

By explanatory dictionary Ushakov cataclysm (Greek kataklysmos - flood) is a sharp change in the nature and conditions of organic life on a large area of ​​the earth's surface under the influence of destructive processes (atmospheric, volcanic). And cataclysm is also a drastic upheaval, and destructive one, in social life.

A sudden change in the physical and geographical state of the surface of the territory can only be provoked by natural phenomena or by the activity of the person himself. And this is a cataclysm.

Hazardous natural phenomena are those that change the state of the natural environment from the range that is optimal for human life. And cataclysmic cataclysms even change the face of the Earth. This is also of endogenous origin.

Below we consider some significant changes in nature that occur under the influence of cataclysms.

Types of natural disasters

All cataclysms in the world have their own peculiarity. And recently they began to occur (and of the most diverse origin) more and more often. These are earthquakes, tsunamis, volcanic eruptions, floods, meteorite falls, mudflows, avalanches and landslides, sudden onset of water from the sea, subsidence of soils, strong and many others. others

Let's give a brief description of the three most terrible natural phenomena.

earthquakes

The most important source of physical and geographical processes is an earthquake.

What is such a cataclysm? These are the shaking of the earth's crust, underground impacts and small fluctuations in the surface of the earth, which are mainly caused by various tectonic processes. Often they are accompanied by a terrifying underground rumble, the formation of cracks, undulating vibrations of the earth's surface, the destruction of buildings and other structures, and, unfortunately, human casualties.

More than 1 million shocks are recorded on planet Earth every year. And this is about 120 shocks per hour or 2 shocks per minute. It turns out that the Earth is constantly in a state of trembling.

According to statistics, on average, 1 catastrophic earthquake and about 100 destructive ones occur per year. Such processes are the consequences of the development of the lithosphere, namely, its compression in some regions and expansion in others. Earthquakes are the most terrible cataclysm. This phenomenon leads to tectonic breaks, uplifts and displacements.

Today, zones of different earthquake activity have been identified on the earth. The zones of the Pacific and Mediterranean belts are among the most active in this regard. In total, 20% of the territory of Russia is prone to earthquakes of varying degrees.

The most terrifying cataclysms of this kind (9 points or more) occur in the regions of Kamchatka, the Pamirs, the Kuril Islands, Transcaucasia, Transbaikalia, etc.

Earthquakes of 7-9 magnitude are observed in vast areas, from Kamchatka to the Carpathians. This includes Sakhalin, Sayans, Baikal, Crimea, Moldova, etc.

Tsunami

When located on the islands and under water, there is sometimes no less cataclysmic cataclysm. This is a tsunami.

Translated from Japanese, this word refers to an unusually huge wave of destructive force that occurs in zones of volcanic activity and earthquakes on the ocean floor. The advancement of such a mass of water occurs at a speed of 50-1000 km per hour.

When approaching the coast, a tsunami reaches a height of 10-50 meters or more. As a result, terrible destruction occurs on the coast. The causes of such a disaster can be underwater landslides, and powerful avalanches that break into the sea.

The most dangerous places in terms of such disasters are the coasts of Japan, the Aleutian and Hawaiian Islands, Alaska, Kamchatka, the Philippines, Canada, Indonesia, Peru, New Zealand, Chile, the Aegean, Ionian and Adriatic Seas.

Volcanoes

About the cataclysm, which is known to be a complex of processes associated with the movement of magma.

There are especially many of them in the Pacific belt. And again, Indonesia, Central America and Japan have a huge number of volcanoes. In total, there are up to 600 of them on land and about 1000 dormant.

Approximately 7% of the earth's population lives in the vicinity of active volcanoes. There are also underwater volcanoes. They are known on the mid-ocean ridges.

Russian dangerous areas - the Kuril Islands, Kamchatka, Sakhalin. And in the Caucasus there are extinct volcanoes.

It is known that today active volcanoes erupt approximately 1 time in 10-15 years.

Such a cataclysm is also a dangerous and terrifying catastrophe.

Conclusion

Recently, anomalous natural phenomena and sudden changes in temperature have been constant companions of life on Earth. And all these phenomena greatly destabilize the planet. Therefore, future geophysical and natural-climatic changes, which pose a serious danger to the existence of all mankind, require all peoples to be constantly ready to act in such crisis conditions. According to certain estimates of scientists, people are still able to cope with the future consequences of such events.