In Japanese, the hieroglyph "CSU" is the bay or bay, "us" - a wave. Together both hieroglyphs are translated as a "wave pouring the bay." The catastrophic consequences of two tsunami, who collapsed on the shores of the Indian Ocean in 2004 and on Japan in 2011, clearly demonstrated that there was no reliable protection against this terrible phenomenon of nature ...

Tsunami - What is it?

Contrary to emerging opinion, tsunami is not one gigantic wave at all, unexpectedly flying ashore and sweeping everything on its path. In fact, the tsunami is a series of marine gravitational waves of a very large length resulting from the shift of the lengthy sections of the bottom with strong underwater earthquakes or occasionally, for other reasons - as a result of eruption of volcanoes, giant landslides, falling asteroids, underwater nuclear explosions.

How does Tsunami arise?

The most common cause of the tsunami is a vertical bottom of the bottom under underwater earthquakes. When the bottom of the bottom is lowered, and the part is raised, the mass of water comes into a oscillatory movement. In this case, the surface of water seeks to return to the initial level - the average level of the ocean - and thus creates a series of waves.

The speed of distribution of the tsunami at the depth of 4.5 km exceeds 800 km / h. But the height of the wave in the open sea is usually small - less than a meter, and the distance between the ridges is a few hundred kilometers, so with the deck of the ship or from the tsunami aircraft just just notice. On the oceanic expanses for any vessel, a meeting with tsunami is not dangerous. But when the waves exit in the shallow water, their speed and length are reduced, and the height increases sharply. At the shore, the wave height often exceeds 10 m, and in exceptional cases it reaches 30-40 m. Then the beaches of the element inflicts the coastal cities of the colossal damage.

However, there are often tremendous destruction of tsunami waves and relatively small heights. At first glance, it seems strange: why externally more terrible waves arising during a storm do not lead to similar victims? The fact is that the kinetic energy of the tsunami is much higher than that of wind waves: in the first case, the whole thickness of the water is moving, and in the second - only the surface layer. As a result, the pressure of the water straightened to the land during the tsunami is many times higher than during the storm.

You should not discount from the account and another factor. With a storm, the excitement increases gradually, and people usually have time to move at a safe distance, before it begins to threaten the danger. Tsunami always comes suddenly.

Today, about 1000 cases of tsunamis are known, of which more than a hundred catastrophic consequences. The geographically dangerous region is the periphery of the Pacific Ocean - there arises about 80% of all tsunami.

It is impossible to fully protect the shore from the tsunami, although in some countries, especially in Japan, they tried to build malls and vololates in order to weaken the power of the blow of the waves. However, there are cases when these structures played a negative role: the tsunami destroyed them, and the pieces of concrete poured into the flows of water only aggravated damage on the shore. The hopes for protection from the trees planted along the shore are not justified. To extinguish the energy of the waves, you need a too large area of \u200b\u200bthe forest stitch, and there is simply no such in most coastal cities. Well, and the narrow strip of trees along the promenade there can be no tsunami resistance.

One of the important measures to protect the population of dangerous regions from the devastating waves was the international system of warning about the tsunami, established in the Pacific region. 25 states, including Russia, take part in her work. Scientists of different countries based on the comprehensive analysis of the zones of strong earthquakes are trying to determine whether they caused the formation of the tsunami in the past, and what is the likelihood of tsunami in the future. The main research center of the system, located on the Hawaiian Islands in Honolulu, continuously monitors the seismic environment and surface level of the Pacific Ocean.

In our country, the warning service of the Tsunami of the Far East consists of three regional services: Kamchatka, Sakhalin regions and Primorsky Territory. In the Kamchatka region, in particular, the Tsunami Station of the Territorial Administration for Hydrometeorology and Environmental Monitoring and the Seismic Station of the Institute of Foreign Physics of the EN Russia are operating.

The most devastating tsunami past

It is possible that the most catastrophic case of the tsunami in the history of mankind occurred in antique times, although he reached us in the form of myths and legends. Approximately 1450 BC. From a gigantic wave, which provoked a Santorini volcano, a whole civilization died. 120 km from the volcano is Crete, the former at the time of one of the most powerful powers of the Mediterranean. But Tsunami, at one point, caused the island of Crete the enormous damage, from which the state who flourished before was not able to recover. It broke up, and many of his cities were abandoned by two and a half thousand years.

Tsunami's gigantic waves followed the destructive earthquake in Lisbon on November 1, 1755. The earthquake focus was obviously located at the bottom of the ocean. The total number of victims from waves and earthquakes is estimated at about 60 thousand people.

In 1883, as a result of a series of eruptions of Volcanana Krakatau in Indonesia, a powerful tsunami was formed, from which the island of Java and Sumatra suffered most of all. Waves up to 40 m high with the face of the earth about 300 villages, more than 36 thousand people died. In the area of \u200b\u200bthe city of Tell Betung, the Dutch warship - Kanonellka "Berouw" - was abandoned in the land of sushi by 3 km and was on the slope of the mountain at an altitude of 9 m above sea level. Seismic waves have passed two or three times around the Earth, and unusual red dawns have long been observed in Europe.

The most destructive tsunami of the twentieth century collapsed on the Chile coast on May 22, 1960. As a result of the tsunami and the magnitude of 9.5 points on the Richter's magnitude, 2000 people were killed, 3,000 were injured, two million were left without bed, and the damage was 550 million US dollars. As a result of the same tsunami, 61 people were killed in Hawaii, 20 in the Philippines, 3 on Okinawa and more than 100 in Japan. The height of the waves on the island of Pitcairn reached 13 m, in Hawaii - 12 m.

The most unusual tsunami

In 1958, at the Lituya Bay in Alaska, a tsunami was formed, caused by a giant landslide - about 81 million tons of ice and solid rocks fell into the sea due to the earthquake that occurred. The waves reached an incredible height of 350-500 m - these are the biggest waves of all registered in history! Tsunami washed off from the slopes of the mountains of all vegetation. Fortunately, the bay shores were unnecessary, and human sacrifices were minimal - only two fishermen died.

Tsunami at the Russian Far East

On April 4, 1923, a strong earthquake occurred in Kamchatka Gulf. After 15-20 minutes later, a wave approached the top of the bay. Two fisheries were completely destroyed on the coast, the village of Ust-Kamchatsk was strongly damaged. The ice on the Kamchatka River was hacked for 7 km. In 50 km south-west of the village there was a maximum height of water lifting on the coast - up to 30 m.

On the territory of Russia, the most catastrophic tsunami occurred on the night from 4 to 5 November 1952 at the Far Eastern Island Paramushir, where the city of North-Kurilsk is located. At about 4 am, the strongest underground shocks began. After half an hour, the earthquake ceased, and people who left the dwellings returned to their homes. Only a few remained on the street and noticed the approaching wave. They managed to hide in the hits, but when they went down to inspect the destruction and wanted their relatives, the second one, an even more powerful water shaft was hit by a height of about 15 m. The captain of one tug, standing on the Ride of North-Kurilsk, told that that night sailors nothing They did not notice, and early in the morning they were surprised to a large number of floating garbage and different items. When morning mist was dissipated, they saw that there were no cities on the shore.

On the same day, the Tsunami reached the shores of Kamchatka and caused serious damage to a number of villages. In total, more than 2,000 people died, but in the USSR until the beginning of the 1990s, almost no one knew about the events of that tragic night.

Tsunami, which emerged on May 23, 1960, off the coast of Chile, about a day reached the shores of Kuril and Kamchatka. The greatest level of water lift was 6-7 m, and in the territory of the Khalaktyra Beach, Petropavlovsk-Kamchatsky - 15 m. In the Bays of Vilyuchinskaya and Russian, household buildings were destroyed and washed into the sea.

Tsunami's distribution in the Pacific Ocean (the most destructive waves - black and red) after the earthquake of 1960. Map prepared by American National Oceanic and Atmospheric Research (NOAA)

Catastrophe in the Indian Ocean (2004)

After the earthquake by force of about 9 points on the Richter scale with the epicenter in the northern part of the island of Sumatra in Indonesia, which happened on the night of December 26, 2004, the Indian Ocean covered the most powerful tsunami. More than 1000-kilometer lifting line, which arose as a result of the movement of large layers of the earth's crust at the bottom of the ocean, gave rise to a huge emission of energy. The waves collapsed on Indonesia, Sri Lanka, India, Malaysia, Thailand, Bangladesh, Myanmar, Maldives and Seychelles and sugared to Somalia, located at a distance of 5 thousand km from the epicenter of the earthquake. More than 300 thousand people became victims of the tsunami, including foreign tourists from many countries, resting in those days in Indonesia and Thailand. Most of the dead turned out to be in Indonesia (more than 180 thousand) and Sri Lanka (about 39 thousand).

Such numerous sacrifices are largely due to the lack of elementary knowledge from the local population about the threatening danger. So, when the sea retreated from the coast, many locals and tourists remained on the shore - from curiosity or from the desire to collect fish remaining in puddles. In addition, after the first wave, many returned to their homes - to evaluate the damage or try to find close, not knowing that others will follow the first wave.

Tsunami in Japan (2011)

The cause of the tsunami was the strongest earthquake of the magnitude of 9.0-9.1 points, which occurred on March 11, 2011 at 2:46 pm local time (8:46 Moscow time). The center of the earthquake was at a depth of 32 km, at a point with coordinates of 38,322 ° C.Sh. 142,369 ° V.D. Eastern island Honshu, 130 km east of Sendai and 373 km north-east of Tokyo. In Japan, Tsunami caused massive destruction on the east coast. The maximum wave height was observed in Miyagi Prefecture - 10 m. Tsunami was flooded by Sendai Airport, one passenger train washed away, made serious damage to Fukushima NPP. Only in Sendai Tsunami caused about 300 people. The general damage caused by the country's economy is calculated by hundreds of billions of dollars.

According to official data, the number of dead as a result of the earthquake and the tsunami was 15,892 people, another 2576 people are missing. 6152 people were seriously injured. According to unofficial data, the number of victims is much larger. According to media reports, only 9,500 people are missing in the city of Minumbrik.

Numerous photocoupes draw a truly apocalyptic picture of destruction:

Tsunami was observed on the entire Pacific coast - from Alaska to Chile, but outside of Japan it looked much weaker. The tourist infrastructure of Hawaii suffered the strongest - only about 200 private yachts and boats were broken down in Honolulu. On the island of Guam Waves, two nuclear submarines of the US Navy are broken from the mooring. In the city of Crusant City in California, more than 30 boats and boats were damaged, one person died.

According to the EMERCOM of Russia, due to the threat of tsunami in the Kuril Islands from the coastal territories, 11 thousand inhabitants were evacuated. The greatest wave height - about 3 m - was recorded in the village of Malokurilsky district.

Tsunami in cinema

In the popular genre of disaster films, Tsunami has repeatedly attracted the attention of scripts and directories. As an example, you can bring the feature film "Tsunami" (South Korea, 2009), frames from which are shown below.

Introduction

Under an emergency, it is customary to understand the situation on a certain territory that established as a result of an accident, a spontaneous or other disaster, which may entail or entailed human sacrifices, damage to the health of people or the environment, significant material losses and violation of the living conditions of the population. The emergencies arise not immediately, as a rule, they develop gradually from the incident technogenic, social or natural nature.

Designing security system. It will also describe in detail and describes the causes of this natural phenomenon, the development process, possible consequences and ways to eliminate and protect against it.

Tsunami, huge sea waves associated mainly with underwater earthquakes, but sometimes emerging with volcanic eruptions at the bottom of the ocean, which can cause the formation of several waves, follow from the interval from a few minutes to several hours. Tsunami is one of the most dangerous natural phenomena, as it entails multiple losses: it is strongly undermined by the economic stability of the country or the state, as well as impose irreparable harm to the living people, up to the mass death of people.

The main area where the tsunami occurs is the Pacific Ocean. Of the 400 current 330 volcanoes operating today in the Pacific Pool, there are more than 80% of all earthquakes.

"Tsunami" translated from the Japanese language means "wave in the harbor". And although this translation sounds somewhat exotically and is a descriptive character, the specified term, as it is impossible, it is better characterized by the essence of the phenomenon.

Tsunami phenomenon

Nature Tsunami

Tsunami is known to the world from time immemorial. The first table described by the Tsunami destroyed the city of Amniceos in Crete about 1400 to our era. It is possible that it is the eruption of Santorin Volcano that caused by him the tsunami caused the disappearance of the Minoan civilization, which was reflected in the legend of the death of Atlantis.

The word "tsunami" itself is formed from two Japanese hieroglyphs: "CSU" means "harbor", "us" - "big wave". This term describes the essence of the phenomenon with literal accuracy. The east coast of Japan is most in the world suffering from the tsunami, because the Japanese word was chosen to designate this phenomenon everywhere.

At the same time, the most general definition of the term "tsunami" was given in 1968 by the American scientist Van-Dorn: "Tsunami is the Japanese name of the system of gravitational waves arising from the sea due to large-scale perturbations of the free surface."

The warning service of the Tsunami of Russia uses such a definition of the tsunami: "Tsunami - long-range waves arising in the oceans and seas, mainly due to underwater earthquakes, as well as the result of eruptions of underwater or island volcanoes or landslides of large mass of earthly rocks."

The winds that follow oceans give rise to waves only in its upper layers. During strong storms, the waves can rise to a height of 30 meters and more, but even they do not affect the inner waters of the ocean and remain only on the surface. The speed of movement of waves caused by conventional winds reaches about 20 km / h, which is immeasurably less than the wave velocity of the tsunami (can reach 1000 km / h).

Conventional waves are an oscillatory movement of the upper layer of water mass of the reservoir. The height of wind waves is usually not more than 4 m, less often - 6-7 m. In the seas it is lower than in the open ocean. The largest measured wave height is 20 m. The average length of the storm waves is about 100 m. The main characteristics of wind waves and tsunami waves are shown in table1. Wave Tsunami Earthquake Cyclone

Table 1 Main characteristics of wind waves and tsunami waves

The height of the tsunami waves in the ocean decreases as it removed from the place of their occurrence in proportion to the distance taken to the degree 5/6. It is impossible to predict which tsunami waves will be the most destructive.

The tsunami wave can be attributed to soliton phenomena. Soliton is defined as a secluded wave (particle-free wave) propagating in the form of an impulse unchanged form. Soliton is a steady education and, therefore, provides the most efficient mechanism for transfer of energy. The existence of such a mechanism is confirmed by such ambitious natural phenomena as tsunami and tornado. Due to the rapid weakening of the height of a conventional storm wave (due to dispersion and divergence), perturbations are localized on the water (otherwise the storm waves, originating in one place, remain dangerous for the entire ocean). The main feature of solitons is the immutability of their form in the distribution process, and, therefore, such waves can spread to very long distances without losing their energy.

Thousands of scientists all over the world are trying to figure out the causes of the tsunami, they want to study how to deal with the tsunami, how to avoid consequences after the tsunami.

If you look at the Japanese-Russian Dictionary, you will find the translation of the word "tsunami" - "Wave in the Harbor". It is clear, there is not a word about how dangerous tsunami is what the causes of the occurrence of the tsunami. But the fact that the translation of the word "tsunami" is accurate - this is a fact. We note that the "tsunami" does not inclined: it is impossible to say "Tsunam", "Tsunamami", "Tsunamov", "Tsunamam". In all cases, the form "Tsunami" is used. But we will not deviate from the topic. We are more interested in what is the tsunami, what the main causes of tsunami.

Tsunami is incredibly huge waves capable of imparting irreparable damage to the living and material world. Despite this fact, to notice the tsunami in the sea is difficult when the tsunami waves come to the shore, they increase in size, become very noticeable, it causes a paralyzing shock. People at the sight of tsunami simply do not know how to behave. Tsunami hypnotize.

Of course, many manits such a unique phenomenon like tsunami. Many are interested in the reasons for the occurrence of the tsunami, the consequences of the tsunami, the ability to prevent the tsunami.

Causes of tsunami: Basic and secondary

For what reason are the tsunami arise? In reality, there are several of them.

Among the main causes of tsunami are:

• The cause of the occurrence of Tsunami No. 1 - underground shocks. The earthquake is considered to be about an 85% key cause of the tsunami. When the seabed is shifting, when one lithospheric plate comes to another, water lifts (tsunami). Those are distinguished by the tsunami from other types of waves: during the tsunami, the whole thickness of the water is involved, and not its superficial part. Tsunami begins where there was a rift of glove plates, in the epicenter of the earthquake. The formed ridges can be of different heights: from a meter to seventy and more. Such a reason for the occurrence of tsunami causes the greatest destruction in coastal zones. Tsunami speed can be 800-900 km / h. When the tsunami is approaching the coastal zone, the energy of the waves becomes more concentrated - and the powerful force is condensed on people, buildings, trees.
• The reason for the occurrence of Tsunami No. 2 - landslides. They happen less often than earthquakes. This cause of the occurrence of the tsunami has a feature: landslides can only be in certain places. Tsunami because of landslides - the phenomenon is infrequent, rarely happen. The landslides cause tsunami in only 7% of cases. They are able to provoke the formation of incredibly high waves: more than 20-30 meters. The power of the tsunami in this case is incredibly destructive. In history, tsunami was recorded, the wave height of which was 524 meters. More often landslides happen in Indonesia. They carry a special danger in the river delta.
• The cause of the occurrence of Tsunami No. 3 is a volcanic eruption. In the oceans, many volcanoes that barely rise above the water stroke, and even more volcanoes are located at the very bottom. In the percentage ratio of volcanoes become the cause of tsunami in 5%.

Other reasons for the occurrence of the tsunami: the fall in the ocean of celestial bodies (comet, meteorites) or huge fragments of rocks, the activities of people (for example, the tsunami arises due to the tests of nuclear, atomic weapons in the oceans, seas).

As you understand, the reasons of the tsunami can be anything, but more often the tsunami is a "gift" of the very Mother of Nature. And people remain only to come to terms with such a "present", learn to survive after the tsunami. It is better, of course, make a maximum effort to anticipate events. Both scientists and ordinary people are concerned about the consequences of tsunami no less than the causes of the occurrence of the tsunami. If with the causes of the tsunami to fight almost impossible, then influence the consequences of the tsunami, they have a chance to minimize them.

Tsunami: Terrible consequences

When we hear the word "tsunami", the first idea coming to the mind - people died. Of course, we are talking about the most terrible subsequent tsunami. But there are others:

• flooding of coastal territories;
• destruction of agricultural land;
• destruction of houses, strategically important objects, buildings, structures;
• damage to ships, boats, other vessels that were moored.

Tsunami does not choose who to destroy, and what to leave safe and preservation.

In order to significantly minimize the damage from the tsunami, the specialists recommend building houses and other objects away from the coast. When to follow this recommendation is not possible, it makes sense to build the most durable buildings, on powerful columns, end towards the shore. Then there is a chance that your home will not break under the tsunami blow.

As for the courts, it is better to take them into the sea immediately, as the probability of tsunami appears.

When it is announced that the tsunami is coming, you need to quickly take documents, some products and vital things, and then go away from the water. You can climb on the mountain (tsunami waves are not always high), you can simply leave for five to ten kilometers (better - more). So there will be more chances of salvation from the tsunami. To accurately predict the strength of the tsunami, the duration of the tsunami cannot neither scientists or already existing equipment.

Look carefully on the signs of the tsunami. They are few. Earthquake - the first harbinger of the tsunami. The second sign of the tsunami is a tump. The third sign of the tsunami is the atypical, unusual behavior of animals. They first feel a threat. When all the harbingers tsunami are combined together, no doubt remains. Need to run! Do not risk, do not stay on the coast. The pleasure of beauty tsunami will be short-term, and life you will not return to yourself. Everyone who see the wave is below her, and therefore they have no opportunity to escape.

If all people understood the nature of the tsunami, if everyone knew what actions should be taken in the event of a tsunami approaching, the victims from the element in the world would be much smaller, and the number of saved would be much more. And this in turn makes the appropriate conclusions.

Tsunami - An incredibly dangerous phenomenon of nature. Terrifying consequences are forced to feel their insignificance. But, as they say, his enemy needs to know in the face, so let's learn more about this angry joke of nature:

The most susceptible to tsunami risk: California, Hawaii, Oregon and Washington. Hawaii, are subject to the greatest risk, and they have about 1 tsunami per year, and dangerous tsunami approximately every 7 years.

On March 28, 1964, an extremely strong earthquake hit Alaska. It caused the tsunami waves, which were very devastating in the southeast of Alaska, Vancouver and Canada. The waves ranged from 6 to 21 feet. As a result, more than 120 people died as a result of Tsunami, and the damage was caused in the amount of more than $ 106 million. It was the most expensive tsunami for the western part of the United States and Canada.
Scientists concluded that the drop of a moderately large asteroid (about 5-6 km in diameter) in the middle of the Atlantic Ocean will generate tsunami, which will travel until the upper two thirds of the United States. Coastal cities will be destroyed by such tsunami.
Nuclear explosions can create tsunami, but there are no test results yet. In addition, such testing is currently prohibited by international treaties.

With underwater earthquake or other large disturbances that cause sudden increase or reduce the mass of water over the affected area. This unexpected movement of water creates a series of powerful waves.
Underwater earthquakes that cause significant changes at the bottom of the ocean and the movement of large volumes of water is the most common cause of tsunami.
Tsunami can also be caused by other underwater events, such as volcanic eruptions and landslides.
Tsunami can also be associated with events above the bottom of the ocean. These events may include the fall of meteorites in the ocean, large landslides near the coastline, materials from the erupting volcano or landslide formation. The consequences of the tsunami caused by such factors are usually localized.
More than 75 percent of the tsunami, caused by submarine earthquakes.

Where tsunami occur?

Most tsunami arise in the Indian and Pacific Oceans. The borders of the Pacific Ocean experiences frequent earthquakes. This border is known as the "Fire Ring". There are two main subduction zones in the Indian Ocean, which can also generate tsunami.
The earthquakes of the subduction zone are the most common source of destructive tsunami. These earthquakes are formed when two tectonic plates are found, and one goes under another. The sinking plate stretches to the upper plate, which leads to bending. The upper plate is restored to its original position, displacing sea water.

In December 2004, an earthquake near the coast of Indonesia led to the fact that 10 minutes after the event, the moved surfaces of the sea occurred in the direction of the epicenter, like tsunami. In this figure, the red arrows indicates the direction in which the upper plate is deformed due to dragging and releases the lower plate.

• In the deep waters of the ocean, waves, are created with a large wavelength, but usually no more than one meter height. The tsunami waves can be hundreds of kilometers in length, and they move at a very high speed and over long distances, without losing the main part of their energy.
• You can see the mini tsunami if you throw a large object into the water.
• Tsunami in the open ocean can move at a speed of 950 kilometers per hour, (this is the speed of the passenger aircraft). Tsunami loses speed when approaching the ground, but it does not lose the bulk of its energy.

• In the open ocean, it can be difficult to notice the waves of the tsunami. However, when the tsunami wave approaches and moves to a smallest depth, the leading edge of the wave slows down, and in the rear, the waves still travel with its original speed. It causes water to frighten into a bunch and leads to an increase in the height of the wave. This process is known as "cropping". When the wave reaches the Earth, it can behave like a series of adaptations or just a large powerful wave.
• Huge wave energy can cause a stream of a large amount of water, which rushes inside the country, far beyond the coastal zone.
• Some of the largest tsunami waves were obtained as a result of the eruption of Krakataau volcano in 1883. That tsunami reached a height of 37 m. In 1737, the tsunami had a wave height of 64 m and above, (his shot fell on the cape of a blade, in the north-east of Russia).
• Tsunami waves differ from normal waves!Normal waves generated by wind and water, which moves near the surface. In the tsunami, all the water from the surface is moving to the bottom of the ocean, and the movement is formed, due to the displacement of water (as a rule, it causes an earthquake). In the open ocean, the tsunami create a slight movement and a greater threat to shipping.
• When the tsunami reaches the shore, its wavelength can be more than 100 km. Tsunami can last for several hours or even days, depending on the location. It is significantly different from the waves that we used to see on the beach. Typical ocean waves usually last less than a minute, and the length of their wave is only 100 meters.
• The tsunami energy is enough to deprive the sand all the beach, snatch trees, and crush the buildings.
• People and boats are powerless against the power of the tsunami. The amount of water involved by the tsunami is able to flood the extensive areas of the usual dry land.

The most famous tsunami lately:

• Solomon Islands April 2, 2007

On April 2, 2007, an earthquake occurred, the force of which was 8.1 points on the Richter scale. The earthquake occurred in shallow water early in the morning and after him quickly followed the tsunami. The waves were up to 10 m in height. More than 50 were registered, and thousands remained homeless. Tsunami warnings were in Australia and Alaska 15 minutes after the earthquake.

• Samoa September 29, 2009

At 6:49 am, an earthquake of 8.0 points caused this tsunami, which caused a large amount of damage to property and the environment, as well as led to the death of more than 100 people.

• Chile February 27, 2010

It caused, earthquake by force of 8.8 points. The epicenter of the earthquake was 115 km from Concepcion. The epicenter of the earthquake was 230 km. This earthquake has become the result of motion between the plates in the eastern part of the Pacific Ocean and South American Plates. The first waves hit about 34 minutes after the earthquake. The buildings were seriously damaged, and more than 200 lives were lost.

• Papua New Guinea July 17, 1998

Earthquake by force of 7.0 points on the Richter scale, in the immediate vicinity of the north coast caused a destructive tsunami. Waves up to 10 meters walked around the villages in the Aitape region very quickly. More than 2000 people were killed, to all, the tsunami brought serious damage to buildings and agricultural land.

• Tsunami in the Indian Ocean December 26, 2004

This tsunami has become one of the most destructive natural disasters in recent years.. An earthquake that caused it, it happened to the west of the Indonesian Sumatra Island, its capacity was 9.0 points on the same scale of Richter, which makes it the largest earthquake worldwide over the past 40 years . The number of those killed in March 2005 amounted to more than 273,000 people, many were missing.

And now the queue of incredible video materials:

Tsunami Thailand - 2004

Japan 2011, tsunami video

Tsunami in Khao Varnish

Tsunami is among the most dangerous catastrophes that can occur on our planet. Only earthquakes and eruption of underground magma are able to compare with them in their consequences.

It is quite natural that, like most other terrible events, tsunami causes considerable interest among humanity. Some are looking for information about what kind of destruction led giant waves throughout the history of human existence or, others are interested, as tsunami occurs, and others want to know what parameters it is characterized. And do the right - warned, it means it is armed.

Tsunami formation process

What is happening under water or near the coast of the earthquake (less often) leads to oscillations of the ocean surface. Moving vertical mass of water causes the appearance not too high, but sufficiently long waves capable of passing at a speed of up to 1000 km / h of several thousand kilometers and reach the shore. Approaching the coastal zone, resets the speed and decreases in length, at the same time increasing in height. What is already the bay or bay, to which the waves have come down, the of them will be higher - sometimes their size exceeds 50 m. However, even ten meter tsunami is enough to create significant destruction.

The main signs of Tsunami

You can learn about the occurrence of tsunami thanks to the alert systems that are certainly available in the cunning areas. Although there are signs of tsunami, noticeable to ordinary people in the coastal zone shortly before the emergence of this natural phenomenon. Among them can be called:

- the rapid retreat of the sea from the coast;

- Underground shocks, indicating the not far from nearby earthquake, which, as is known, can lead to the occurrence of tsunami;

- Numerous floating on the surface of water wreckage of various origin, and sharp water springs at the edge of the ice or reefs.

Tsunami accompanying factors

As a rule, the occurrence of the tsunami is accompanied by the devastating consequences that are caused by such factors as the effect of the sea first, and then the air wave, as well as hydrodynamic pressure.

Secondary factors of the passage of phenomena are:

- Flooded terrain;

- destroyed buildings;

- dead people and animals;

- contaminated water and soil (which can lead, in turn, to the emergence and dissemination of infections);

- Destroyed forests and agricultural land.

Tsunami and their characteristics

The main characteristics for this natural phenomena are:

- The tsunami wave height, that is, the vertical distance from its crest to the sole. If this value occurs, 0.5-5 m is equal, but 70 m can be achieved near the coast;

- The wavelength equal to the distance between the ridges of adjacent waves. Usually this value lies between one to several dozen (less often - up to two-hundred) kilometers and depends on the depths of the ocean;

- The speed with which the tsunami is moving. It is usually within 50-100 km / h throughout the main part of the route, although not far from the epicenter sometimes there are 1000 km / h.

Tsunami intensity scale

By its intensity, the tsunami is divided into 6 main types. Such a classification of tsunami allows you to characterize the consequences of their action:

- 1 point means that only devices registered the element. Most people do not even know about such tsunami;

- Tsunami with intensity in 2 points can be a little flooded shore, but to distinguish it from ordinary ocean unrest, again, only specialists are capable of;

- 3 points says that the tsunami became noticeable. Small boats may be thrown ashore;

- 4 points. Destruction is quite serious, buildings are damaged, the ships nail to the shore and even throws on it;

- the five-point tsunami destroys the buildings and can lead to the death of people;

- Element, the intensity of which reaches six points, empties the coast almost completely.