Thousands of scientists around the world are trying to understand the causes of tsunamis, they want to study how to deal with tsunamis, how to avoid the consequences after a tsunami.

If you look in the Japanese-Russian dictionary, you will find the translation of the word “tsunami” - “wave in the harbor.” Of course, there is not a word there about how dangerous tsunamis are, what are the causes of tsunamis. But the fact that the translation of the word “tsunami” is accurate is a fact. Please note that “tsunami” is not inflected: you cannot say “tsunami”, “tsunami”, “tsunami”, “tsunam”. In all cases the tsunami form is used. But let's not deviate from the topic. We are more interested in what a tsunami is, what are the main causes of a tsunami.

Tsunamis are incredibly huge waves that can cause irreparable damage to the living and material world. Despite this fact, it is difficult to notice a tsunami at sea; when tsunami waves come to the shore, they increase in size, become very noticeable, and this causes a paralyzing shock. When people see a tsunami, they simply don’t know how to behave. Tsunamis are hypnotizing.

Of course, many are attracted by such a unique phenomenon as a tsunami. Many people are interested in the causes of a tsunami, the consequences of a tsunami, and the possibility of preventing a tsunami.

Causes of tsunamis: main and secondary

Why do tsunamis occur? In fact, there are several of them.

Among the main causes of tsunamis are:

• The number 1 reason for a tsunami is tremors. An earthquake is considered approximately 85% to be the key cause of a tsunami. When the seafloor shifts, when one lithospheric plate slides over another, water rises (tsunami). This is what distinguishes tsunamis from other types of waves: during a tsunami, the entire thickness of the water is involved, and not its surface part. A tsunami begins where the earth's plates break, at the epicenter of an earthquake. The resulting ridges can be of different heights: from a meter to seventy or more. This cause of tsunami causes the greatest destruction in coastal areas. The speed of a tsunami can be 800-900 km/h. When a tsunami approaches the coastal zone, the energy of the waves becomes more concentrated - and a powerful force hits people, buildings, and trees.
• Cause of tsunami No. 2 is landslides. They happen less often than earthquakes. This cause of a tsunami has a peculiarity: landslides can only occur in certain places. Tsunamis due to landslides are an infrequent phenomenon and rarely occur. Landslides cause tsunamis in only 7% of cases. They are capable of triggering the formation of incredibly high waves: more than 20-30 meters. The power of the tsunami in this case is incredibly destructive. In history, a tsunami was recorded whose wave height was 524 meters. Landslides occur more often in Indonesia. They pose a particular danger in river deltas.
• Cause of tsunami No. 3 is a volcanic eruption. There are many volcanoes in the oceans that barely rise above the surface of the water, and even more volcanoes are located at the very bottom. As a percentage, volcanoes cause 5% of tsunamis.

Other causes of a tsunami: the fall of celestial bodies (comets, meteorites) or huge fragments of rocks into the ocean, human activity (for example, a tsunami occurs due to testing of nuclear and atomic weapons in the oceans and seas).

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

Tsunami: terrible consequences

When we hear the word “tsunami”, the first thought that comes to mind is that people died. Of course, we are talking about the most terrible consequence of a tsunami. But there are others:

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

The tsunami does not choose who to destroy and what to leave safe and sound.

In order to significantly minimize damage from a tsunami, experts recommend building houses and other objects away from the shore. When it is not possible to follow this recommendation, it makes sense to erect the most durable buildings possible, on powerful columns, with their end faces towards the shore. Then there is a chance that your house will not break under the impact of a tsunami.

As for ships, it is better to put them out to sea as soon as there is a possibility of a tsunami.

When it is announced that a tsunami is approaching, you need to quickly take documents, some food and vital things, and then go away from the water. You can climb a mountain (tsunami waves are not always high), or you can simply go five to ten kilometers (more is better). This will give you a better chance of being saved from a tsunami. Neither scientists nor existing equipment can accurately predict the strength of a tsunami or the duration of a tsunami.

Look carefully for signs of a tsunami. They are few. An earthquake is the first harbinger of a tsunami. The second sign of a tsunami is low tide. The third sign of a tsunami is atypical, unusual behavior of animals. They are the first to feel threatened. When all the warning signs of a tsunami come together, there is no longer any doubt. We must run! Don't take risks, don't stay on the coast. The pleasure from the beauty of the tsunami will be short-lived, and you will never get your life back. Everyone who sees the wave is below it, which means they have no way to escape.

If all people understood the nature of tsunamis, if everyone knew what actions should be taken in the event of an approaching tsunami, there would be much fewer casualties from the elements in the world, and the number of survivors would be much greater. And this, in turn, forces us to draw appropriate conclusions.

| Origin and classification of tsunamis. Consequences of the tsunami

Basics of life safety
7th grade

Lesson 18
Origin and classification of tsunamis. Consequences of the tsunami

FROM THE HISTORY OF TSUNAMI

Ten-year-old British schoolgirl Tilly Smith was vacationing with her parents in Thailand on the island of Phuket. There were no signs of trouble, but on December 26, 2004, the girl noticed that the water level in the sea had dropped sharply, and the water was rapidly moving away from the shore. Tilly remembered that recently, in a geography lesson, she had learned the signs of a tsunami, which she now saw in reality. The girl immediately informed her mother about the impending danger, and then, with the help of hotel staff, the tourists relaxing on the beach. The Marriott Hotel in Phuket was one of the few where no guests were killed or seriously injured, thanks to the schoolgirl's knowledge. Tilly Smith was invited to the United Nations, where she met with former US President Bill Clinton, the UN envoy for the reconstruction of tsunami-damaged areas. Tilly's story is a simple reminder that knowledge can be the only difference between life and death, Clinton said after talking with the girl. The UN is currently running a worldwide campaign to educate people about how to deal with natural disasters. The described incident is one of the few happy episodes of the tragedy that claimed the lives of 300 thousand people.

At 3:58 am Moscow time on December 26, 2004, as a result of the collision of the Indian, Burmese and Australian lithospheric plates, the largest underwater earthquake in the history of the Indian Ocean occurred (magnitude 9). The vertical displacement of the layers of the earth's crust at the epicenter of the earthquake for more than 1000 km was equal to 8-10 m. As a result of the earthquake, a giant tsunami wave was formed in the ocean. Its height in the open ocean was 0.8 m, in the coastal zone - 15 m, and in the splash zone - 30 m. The wave speed in the open ocean reached 720 km/h, and as it slowed down in the coastal zone it decreased to 36 km/h . 15 minutes after the first shock, the wave reached and swept away the northern tip of the island of Sumatra. After 1.5 hours it hit the coast of Thailand, and after 2 hours it reached Sri Lanka and India. In 8 hours it passed the Indian Ocean, and in 24 hours, for the first time in the history of wave observations, it circled the entire World Ocean. Even on the Pacific coast of Mexico, the wave height was 2.5 m.

Having reached the gentle shores, the waves slowed down and, entering shallow water, literally covered unsuspecting people. First, they demolished the coastal cities of Sumatra, then, having reached the Nicobar Islands, they washed away everything in their path, only a handful of people survived, who found salvation in the treetops. Moving into the Andaman Sea, deadly waves hit Thailand. The wave spread westward, crossed the Indian Ocean at the speed of a jet, and crashed off the coast of India and Sri Lanka. Six hours later, the giant waves reached the coast of Africa and then continued their journey around the globe until they dissipated into the ocean.

In total, the disaster affected 50 countries, but Sri Lanka, India, Indonesia, Thailand, Malaysia, Myanmar, Maldives, Somalia, Kenya and some other states and territories were hit the hardest. Human losses exceeded 300 thousand people. In total, about 5 million people were affected by the disaster. Three quarters of all human casualties from this tsunami occurred in Indonesia.

Economic damage from the tsunami exceeded US$14 billion. The world community has allocated $11.4 billion to eliminate the consequences of the tsunami in the Indian Ocean countries.

The coasts of 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 are most susceptible to tsunamis. On the Hawaiian Islands, tsunamis with an intensity of 3-4 occur on average once every 4 years, on the Pacific coast of South America - once every 10 years.

A tsunami with a wave height of more than 2 m is considered potentially destructive. Since 1952, about 60 tsunamis have been recorded, including 15 potentially destructive.

On the night of November 3 to 5, 1952, the city of Severo-Kurilsk on the island of Paramushir, along with industrial enterprises, institutions, and housing, was washed out to sea by a giant tsunami wave formed as a result of an underwater earthquake. The total number of deaths exceeded 14 thousand people.

Origin and classification of tsunamis

Tsunamis are giant ocean waves that usually arise as a result of underwater or island earthquakes or underwater volcanic eruptions. In addition, tsunamis are possible when coastlines collapse as a result of underwater landslides or explosions in the water. The passage of a series of such waves sometimes lasts several hours with intervals between waves of 20-30 minutes.

Word "tsunami" Japanese and is formed by two characters: “tsu”, which means “harbour” and “nami” - “big wave”. In other words, it means a big wave in the harbor, which pretty much sums up the phenomenon.

Depending on the causes of their occurrence, tsunamis are distinguished, generated by underwater and coastal earthquakes, large eruptions of underwater volcanoes and landslides on the seabed.

Tsunami waves can travel several thousand kilometers. In the open sea, when the depth is sufficiently great, their height usually does not exceed several meters, and they do not pose much of a danger. As they approach the shore, having reached shallow water, the waves slow down their movement and increase significantly in height, reaching in some cases 50-70 m. The steeper the shore, the greater the wave height. The tsunami wave may not be the only one. Often this is a series of waves. The highest wave in the series is called the main wave.

Often before a tsunami begins, the water recedes from the coastline, exposing the bottom for several kilometers. Then the waves roll in quickly. Reaching a height of several tens of meters, tsunami waves have a speed of about 90 km/h.

The classification of tsunamis by causes of occurrence and intensity is shown in Diagram 20.

The tsunami intensity based on the impact on the coast (the consequences of this impact) is assessed on a conventional 6-point scale.

I point- very weak tsunami. The wave is noted (recorded) only by special instruments - seaographers. The wave height on the shore is 0.5-1 m.

II points- weak tsunami. May flood flat coasts. Only specialists notice it. Wave height is about 1 m.

III points- average tsunami. The flat coast is flooded and light vessels may be washed ashore. Port facilities may be subject to minor damage. Wave height is about 2 m.

IV points- strong tsunami. The coast is flooded. Coastal buildings are damaged and have mild to moderate damage. Large sailing vessels and small motorized vessels have been washed ashore and then washed back out to sea. The shores are littered with sand, silt, fragments of stones, trees, and garbage. Possible casualties. Wave height is about 3 m.

V points- a very strong tsunami. Coastal areas are flooded. Breakwaters and piers are badly damaged. Vessels, even large ones, are washed ashore. The damage is also extensive in the interior parts of the coast. Buildings and structures have strong, medium and weak damage depending on the distance from the coast. Everything around is strewn with rubble. There are high storm surges at river mouths. Loud sound of waves. There are human casualties. Destruction along the front along the coast - up to 400 km. Wave height is about 8-23 m.

VI points- catastrophic tsunami. Complete devastation of the coast and coastal areas. The land is flooded to considerable distances inland from the seashore. Large loss of life. Destruction along the front along the coast is more than 500 km. The wave height is more than 23 m.

Consequences of the tsunami

The destructive power of a tsunami depends on the speed of the wave, the direction of its movement in relation to the shore, the contour of the coastline, the topography of the coast, the coastal slope and the shelf.

Greatest tsunami impact flat coasts are susceptible. Although when approaching a gently sloping shore its impact decreases, the flood zone is very large.

The main damaging factors of a tsunami are the impact of the wave, erosion of the foundations of buildings, bridges and roads, and flooding.

Tsunami, having high speed, high density of matter and enormous mass, have a colossal destructive effect. Running into an obstacle, the wave unleashes all its energy on it, rising above it like a huge wall, crushing, destroying and destroying it.

Tsunamis can cause mass destruction of people, destroy buildings and other structures, throw heavy objects, including ocean-going ships, over considerable distances from the shore, overturn trains, demolish homes, move houses, destroy rocks and sometimes the concrete foundations of lighthouses. Even weak tsunamis damage ships, port facilities and equipment. Significant damage is also caused by floating objects (including small vessels and cars) and debris, which become dangerous ramming objects.

Tsunamis are especially dangerous for villages, cities and buildings located on the low-lying shores of the ocean, as well as those located at the tops of bays and bays, wide open to the ocean and tapering wedge-shaped towards land.

The air wave that the water mass carries in front of it also has a dangerous effect on people, buildings and structures. She breaks out windows, doors, demolishes roofs and houses. The impact of an air wave on people is to a certain extent similar to the impact of an explosive shock wave.

Secondary consequences of the destructive effects of a tsunami can be fires resulting from damage to oil storage facilities, fire-hazardous enterprises, and sea vessels. The destruction of chemically and radiation hazardous objects, as well as utility systems, can cause chemical, radiation or other contamination over vast areas. The secondary consequences of a tsunami in terms of severity and extent of damage can be many times greater than its direct consequences.

A tsunami is not dangerous away from the coast. Therefore, ships that managed to leave the harbor and move far enough from the coast (at least 6-8 km) are not exposed to the destructive waves. However, ships in the ocean above the epicenter of an underwater earthquake causing a tsunami may experience seaquakes. Underwater seismic tremors are transmitted through the water column to the ship's hull in the form of a series of shocks. During a strong sea earthquake, engines, steering, some instruments and equipment may be damaged, and the crew may be knocked off their feet.

In the section on the question Why are tsunamis not dangerous in the open ocean? given by the author Discard the best answer is because the wave goes along the bottom of the ocean, and closer to the shore the depth is shallower and it gradually rises to the top, but in deep water this is not noticeable.

Answer from Device[guru]
In the open ocean, the tsunami wave is not high.
But as it approaches the shore, its height and destructive power grow.

Answer from Which is what it is.[guru]
And who said that? Tsunamis are dangerous everywhere.

Answer from RIPvanWINKLE[guru]
The height of the wave is two to three meters: it will lift the ship and lower it gently... The wave is flat, its height increases only when approaching a shallow and narrow place.

Answer from chevron[guru]
Because the wave travels underwater and is almost unnoticeable. And it rises to the top of the shore...

Answer from Diam[guru]
The wave size is very large. It will lift the ship, carry it hundreds of meters and lower it smoothly. And near the shore it will inevitably throw it onto land.

Answer from Masha It doesn't matter[guru]
Due to the fact that wave height is inversely proportional to depth, in the open ocean a tsunami wave has a height of no more than 2 meters. Only when approaching the shore does the wave gain height.
In the open ocean, the real danger is posed by the so-called. killer waves. Multimeter waves, the exact nature of which has not yet been established, but they are not of seismic origin.
tsunami -
killer waves-
video -

Answer from Svetlana vishnevskaya[guru]
wavelength is long

Answer from Maxim Yu. Volkov[guru]
In the open ocean, tsunami waves propagate at a speed where g is the gravitational acceleration and H is the depth of the ocean (the so-called shallow water approximation, when the wavelength is significantly greater than the depth). With an average depth of 4000 meters, the propagation speed is 200 m/s or 720 km/h. In the open ocean, the wave height rarely exceeds one meter, and the wave length (the distance between crests) reaches hundreds of kilometers, and therefore the wave is not dangerous for shipping. When waves enter shallow water, near the coastline, their speed and length decrease, and their height increases. Near the coast, the height of a tsunami can reach several tens of meters. The highest waves, up to 30-40 meters, form along steep shores, in wedge-shaped bays and in all places where focusing can occur. Coastal areas with closed bays are less dangerous. A tsunami usually appears as a series of waves; since the waves are long, more than an hour can pass between wave arrivals. That is why you should not return to the shore after the next wave leaves, but wait a few hours.

A tsunami is a natural disaster that anyone can face. Even if you don't live in a tsunami-prone area, you may find yourself in one on vacation or on a business trip. And therefore, any person should know how to behave when such a phenomenon occurs.

You need to understand that a tsunami is not just a large wave, but a much more powerful force, which is described by a separate physical formula and has a force almost equal to the force of an explosion. In the sea, a tsunami is practically invisible - the wave gains its height and power when it approaches shallow water.

What not to do during a tsunami

To begin with, we will tell you what not to do during a tsunami so that you do not make serious mistakes.

Firstly, you cannot stand in fascination and look at a huge wave, rooted to the spot. This recommendation may seem strange to you: who would even think of standing and watching? But, as practice shows, many do just that. Either out of horror, or out of interest.

Secondly, if the tsunami is already very close, simply running will not help, because the wave moves at a speed of 800 km per hour (airplane speed), but the closer to the shore, the slower it becomes: the speed decreases to 80 km per hour.

Thirdly, if the tsunami is still far away, but is already known, most likely you have no more than 15-20 minutes to escape. Therefore, instead of packing our things, we use the time to escape. We take only what is necessary. Save not things, but lives!

Fourthly, you should not run near river beds: it is the river beds that will flood first during a tsunami.

Signs of a tsunami

When a tsunami hit the shores of Thailand in 2004, vacationers were amazed that the bottom was exposed for many kilometers and various shells became visible, which people began to collect. But on one beach, vacationers were saved by the knowledge of a schoolgirl, who had studied the topic of tsunamis in a geography lesson the day before and in time recognized the exposure of the seabed as a sure sign of the onset of a wave, and also informed everyone around her about it, so that they managed to evacuate.

Signs of a tsunami include:

• earthquake
• unusual behavior of water: it either retreats many meters, or, conversely, begins to “lubricate” the surface of the earth, going beyond the water area
• animals have escaped from the shore or are acting anxiously
• the appearance of a white wave edge on the horizon
• sharp rise of the sea horizon
• all people are running from the sea
• warning siren blares

What to do during a tsunami

If you don't see a tsunami yet, but the warning siren is already blaring, or you only saw a tsunami on the horizon, then you have 10 to 20 minutes to leave the area.

Immediately start running in the other direction from the sea. Do not stop until you move 3-4 kilometers inland or are at an altitude of 30 meters. Usually this is enough to save yourself.

If you are trapped and cannot escape from the shore, climb up. This is not the best solution, so we use it only if all other solutions are not available. You can climb onto the roof of a building, or you can choose a strong, tall tree for shelter.

When you take a position from where you will wait for the wave to arrive or start running, try to get rid of heavy items of clothing (jackets, etc.) as you move, which will drown you if the wave hits you.

If you fall into water, climb onto a floating object and use it as a raft. Whenever possible, try to climb a tree, building, or other safe place.

If you find yourself in a tsunami, you have a chance of dying not from drowning, but from being hit by some floating object. Therefore, try to protect yourself from such objects.

When the wave reaches its limit on land, it will begin to retreat back with enormous power. Being in the water at this time is extremely dangerous, as you will simply be carried away into the ocean. Therefore, whenever possible, try to get out of the water, even if just by clinging to a tree, in order to overcome the force carrying you into the ocean.

What to do after a tsunami

When the tsunami has receded, you cannot return to your home or hotel or go to the shore. The first wave may be followed by a second and third, and they may be stronger. Therefore, you need to stay away from the coast, or even better, try to go deeper into the island or mainland so that the second and third stronger waves do not overtake you. Only when the authorities give a signal that the waves have ended can you return to the house.

When you enter a house, if there is anything left of it, you need to beware of objects that could fall on your head. You may also get an electric shock. Therefore, you can enter the room only after making sure that everything is in order.

If you are just going on vacation

Of course, it’s not very pleasant to think about bad things before going on vacation. But still, forewarned is forearmed. So first find out if tsunamis have hit this coastal region before. Although even if they didn’t collapse, this is not a guarantee. It is worth considering that most tsunamis occur in a place called the “volcanic belt”. This is an area in the Pacific Ocean known for its volcanic activity. However, tsunamis occur in all oceans, so if you are on the ocean coast, it is potentially dangerous. You should not refuse such a vacation, you just need to study the signs of a tsunami and strictly follow all the rules.

A giant wave never appears just like that, the main thing is to have an idea of ​​​​the dangerous regions and take precautions.

Causes of tsunamis

• Tsunamis are caused by earthquakes, but not every earthquake will necessarily cause a tsunami.
• Experts associate the Great Lisbon earthquake of 1755, which killed more than 50 thousand people off the coast of Spain and Portugal, with the tidal effects of the Moon and Sun on the earth's crust.
• The 1998 tsunami, which destroyed everything in its path in the Papua New Guinea region, was caused by a landslide, the collapse of which, in turn, was provoked by a moderately powerful earthquake ().
• So-called “meteorological” tsunamis appear against the background of typhoons: after a sharp turn of the typhoon to the side, the resulting wave can continue to move independently (for example, the 2011 tsunami in the area of ​​the English city of Plymouth was caused by a storm in the Bay of Biscay).
• “Exclusive” tsunamis occur as a result of underwater volcanic eruptions (for example, the tsunami of 1883, formed after the eruption of the Krakatoa volcano), meteorite falls (a National Geographic channel documentary mentions traces of a tsunami that remained in the state of Texas after a meteorite fell 65 million years ago ) and man-made disasters.

Philippines, Malay Archipelago

The Philippine islands are located in a seismically active zone. And where there are earthquakes, there are tsunamis, and it is impossible to predict which of the seven thousand islands will be hit this year. In 2013, these were the islands of Samar and Leyte, where waves up to 5 meters high claimed the lives of 10 thousand people and left about half a million local residents homeless. And the worst tsunami in the history of the Philippines occurred in 1976, when, as a result of an earthquake in the Cotabato Trench, a wave hit the island of Mindanao, killing 8 thousand people.

Gizo, Solomon Islands

The Solomon Islands, tiny pieces of land scattered across the Pacific Ocean, are defenseless against the destructive power of a tsunami, which was confirmed in 2007, when the cities of Gizo and Noro completely disappeared under water.

Honshu, Japan

In 2012, a 7.9 magnitude earthquake that occurred near the Philippine city of Guan triggered a tsunami just over half a meter high in Japan that covered the capital region and Fukushima Prefecture. There is no comparison with the truly horrific destruction of 2011, when a magnitude 9 earthquake, dubbed the Great East Japan Earthquake, was followed by a tsunami up to 40 meters high, flooding an area of ​​561 square kilometers.

The greatest impact occurred in Miyagi Prefecture (327 km 2), and the highest wave height (40.5 meters) was recorded in Iwate Prefecture. Considering that the word “tsunami” itself came to us from the Japanese language (literally translated as “big wave in the harbor”), the Japanese, who had been familiar with this natural phenomenon for centuries, were not prepared for a tragedy of such magnitude.

Maldives

Despite its seemingly vulnerable position, the Maldives archipelago experienced its only major tsunami in 2004. There is a threat, but coral reefs serve as a reliable natural defense system for the island from surprises from the ocean.

More dangerous than a wave

• The mechanism of tsunami formation differs from the mechanism of formation of an ordinary wave, and this is where its danger lies.
• In a strong wind, the height of an ordinary wave can significantly exceed the height of an average 5-meter tsunami and even reach 20 meters, but the length of such a wave is no more than a couple of hundred meters.
• During underwater earthquakes, the entire thickness of water comes into motion, so the length of the tsunami wave is measured in thousands of kilometers, and the speed can reach 1000 km/h.
• An ordinary wave is driven by the wind, but a tsunami carries a huge charge of energy, moving towards land with all its might.
• While a storm wave in narrow spaces loses its pressure, the power of a tsunami, on the contrary, is concentrated there, and it destroys everything in its path.

Phuket, Thailand

An underground earthquake with tremors of 9.0 magnitude brought death and destruction to the Thai island of Phuket in 2004. Despite the fact that the epicenter of the earthquake was in the Indian Ocean near the island of Sumatra, the subsequent tsunami reached the shores of Indonesia, Thailand, Sri Lanka, India and even South Africa. Three waves hit each other in turn, leaving numerous buildings, local residents and tourists underwater.

Hilo, Hawaii

In the Hawaiian Islands, more precisely, in the city, the International Tsunami Warning Service is located. The location was not chosen by chance: Hawaii is regularly covered by waves about 2 meters high, with the main impact falling on the city of Hilo, which is located on the shore of the bay of the same name. Despite the small wave height, Hawaiian tsunamis are among the most dangerous, since if a person gets caught in a tsunami wave on one of the local sandy bays with a very short beach, he will simply be smashed against the rocks. But if you are careful, there is nothing to worry about: all such areas are marked with warning signs, and sirens are installed along the shores of the islands.

Alaska, USA

Alaska suffered two powerful tsunamis in a row: in 1957 and 1958, giant waves covered Andreanova Island and Lituya Bay, respectively. In 1958, the wave was so powerful that it actually destroyed an entire strip of land - the La Gaussy spit.

Kamchatka, Russia

Tsunami waves come to Kamchatka from an earthquake-prone zone, which is located in the Kuril-Kamchatka and Aleutian trenches. The three most powerful attacks of ocean waters occurred in the last century: in 1923, the wave height reached 30 meters, in 1952 - 15 meters, in 1960 - 7 meters.

Iquique, Chile

On May 22, 1960, a magnitude 9.5 earthquake occurred near the Chilean city of Valdivia, the strongest earthquake in modern human history. And of course, there was a tsunami: in addition to the damage caused directly to the Chilean coast by a 20-meter wave, it reached Alaska, the shores of the Kuril Islands, Japan and overwhelmed the Hawaiian city of Hilo, carrying about 6 thousand people into the ocean. In 2014, residents of the port town of Iquique were evacuated, where a two-meter tsunami wave arrived after an 8.2 magnitude earthquake.

Acapulco, Mexico

Despite the fact that the 7.2 magnitude earthquake that occurred in April 2014 did not cause a tsunami, the Mexican resorts of Acapulco and Zihuatanejo are under constant threat of the sudden arrival of a rogue wave. So if the ocean suddenly retreats from the shore, it’s time to run.

Tsunami statistics

What to do if “covered”

• If you are in the coastal area and feel an earthquake, leave the shore within 15-20 minutes.
• If you did not feel the earthquake, you can guess that a tsunami is approaching by the strong ebb of the tide.
• While the tsunami is approaching, do not waste time under any circumstances: do not go down to look at the exposed seabed, do not film the wave. Immediately look for a hill at least 40 meters in height, preferably warning others about the danger, without causing panic.
• If you are in a building (such as a hotel) and there is no time to find higher ground, go to the upper floors of the building and barricade the windows and doors. Find a safe place: there should be no potentially dangerous objects near you (such as cabinets that could fall or mirrors that could break).
• If you are unable to find a hill, try to take cover behind any significant obstacle for the water (for example, a strong, tall tree or large stone) and cling to it so that you do not get carried away by the flow of water into the ocean.
• If a tsunami finds you on the open sea (for example, you were on a ship and you were thrown into the water by a wave), do not panic, take a breath, group yourself and cover your head with your hands. Having surfaced, get rid of wet clothes as quickly as possible and find any object that you can cling to (in 2004 in Thailand, one of the survivors managed to swim out by clinging to the tail of a crocodile, and another to a python).
• After the storm has passed, do not return to the sea for 2-3 hours: a tsunami is a series of waves.

Photo: thinkstockphotos.com, flickr.com