The largest tsunami in human history. The biggest wave in the world
On the pages of our website we have already talked about one of the most dangerous natural phenomena - earthquakes: .
These fluctuations earth's crust often generate tsunamis, which mercilessly destroy buildings, roads, piers, leading to the death of people and animals.
Let's take a closer look at what a tsunami is, what are the causes of its occurrence and the consequences it causes.
What is a tsunami
Tsunamis are high, long waves generated by a powerful impact on the entire thickness of the ocean or sea water. The term “tsunami” itself is of Japanese origin. Its literal translation is “a big wave in the harbor” and this is not in vain, since in all their power they manifest themselves precisely on the coast.
Tsunamis are generated by a sharp vertical displacement lithospheric plates composing the earth's crust. These gigantic vibrations vibrate the entire thickness of the water, creating a series of alternating ridges and depressions on its surface. Moreover in the open ocean these waves are quite harmless. Their height does not exceed one meter, since the bulk of the oscillating water extends below its surface. The distance between the ridges (wavelength) reaches hundreds of kilometers. The speed of their spread, depending on the depth, ranges from several hundred kilometers to 1000 km/h.
Approaching the shore, the speed and length of the wave begins to decrease. Due to braking in shallow water, each subsequent wave catches up with the previous one, transferring its energy to it and increasing its amplitude.
Sometimes their height reaches 40–50 meters. Such a huge mass of water, hitting the shore, completely devastates the coastal zone in a matter of seconds. The extent of the destruction area deep into the territory in some cases can reach 10 km!
Causes of tsunami
The connection between tsunamis and earthquakes is obvious. But do vibrations in the earth's crust always generate tsunamis? No, tsunami are generated only by underwater earthquakes with a shallow source and magnitude greater than 7. They account for about 85% of all tsunami waves.
Other reasons include:
- Landslides. Often a whole chain of natural disasters can be traced - a shift of lithospheric plates leads to an earthquake, which generates a landslide that generates a tsunami. This is precisely the picture that can be seen in Indonesia, where landslide tsunamis occur quite often.
- Volcanic eruptions cause up to 5% of all tsunamis. At the same time, gigantic masses of earth and stone, soaring into the sky, then plunge into the water. A huge mass of water is shifting. Ocean waters rush into the resulting funnel. This dislocation generates a tsunami wave. An example of a catastrophe of absolutely terrifying proportions is the tsunami from the Karatau volcano in 1883 (also in Indonesia). Then 30-meter waves led to the death of about 300 cities and villages on the neighboring islands, as well as 500 ships.
- Despite the presence of our planet’s atmosphere, which protects it from meteorites, the largest “guests” from the universe overcome its thickness. When approaching the Earth, their speed can reach tens of kilometers per second. If such meteorite has a large enough mass and falls into the ocean, it will inevitably cause a tsunami.
- Technological progress has brought not only comfort to our lives, but has also become a source of additional danger. Conducted underground testing nuclear weapons, this is another reason for the occurrence of tsunami waves. Realizing this, the powers possessing such weapons entered into a treaty prohibiting their testing in the atmosphere, space and water.
Who studies this phenomenon and how?
The destructive effect of the tsunami and its consequences are so enormous that humanity has become the problem is to find effective protection against this disaster.
The monstrous masses of water rolling onto the shore cannot be stopped by any artificial protective structures. Most effective protection in such a situation, there can only be timely evacuation of people from the danger zone. For this a sufficiently long-term forecast of the upcoming disaster is necessary. Seismologists do this in collaboration with scientists from other specialties (physicists, mathematicians, etc.). Research methods include:
- data from seismographs recording tremors;
- information provided by sensors carried out into the open ocean;
- remote measurement of tsunamis from outer space using special satellites;
- development of models for the occurrence and propagation of tsunamis under various conditions.
Tsunamis are the largest and most powerful ocean waves that sweep away everything in their path with terrifying force. The peculiarity of such a dangerous natural disaster is the size of the moving wave, its enormous speed, and the gigantic distance between the crests, which reaches tens of kilometers. Tsunamis pose an extreme danger to the coastal zone. Approaching the shore, the wave gains enormous speed, contracts in front of the obstacle, grows significantly in size and deals a crushing and irreparable blow to the land area.
What causes this huge influx of water, which leaves even the tallest and fortified structures no chance of survival? What natural forces can create a water tornado and deprive cities and regions of the right to survive? Movement tectonic plates and splits in the earth's crust are the worst harbingers of the collapse of a giant stream.
The largest tsunami in the world in the history of mankind
What is the known largest wave in the world? Let's look through the pages of history. The date July 9, 1958 is well remembered by Alaskans. It was this day that became fatal for the Lituya fjord, which is located in the northeastern part of the Gulf of Alaska. Harbinger historical event there was an earthquake, the strength of which was measured to be 9.1. This is what caused the horrific rockfall that caused the collapse rocks and a wave of unprecedented magnitude.
The weather was clear and sunny all day on July 9th. The water level dropped by 1.5 meters, fishermen on ships were fishing (Lituya Bay has always been a favorite place for avid fishermen). Towards evening, around 22:00 local time, a landslide that rolled into the water from a height of 910 meters, followed by huge stones and blocks of ice. The total weight of the mass was approximately 300 million cubic meters. The northern part of the Lituya Bay was completely flooded with water. At the same time, a gigantic pile of stones was thrown to the opposite side, as a result of which the entire green area of the Fairweather coast was destroyed.
A landslide of this magnitude provoked the appearance of a huge wave, the height of which was 524 meters! This is approximately a building of 200 floors! It was the largest and highest wave in the world. The gigantic force of the ocean water literally washed away Lituya Bay. The tidal wave picked up speed (by this time it had already accelerated to 160 km/h) and rushed towards Cenotaph Island. Terrible landslides simultaneously descended from the mountains to the water, carrying a column of dust and stones. The wave rose to such a size that the foot of the mountain disappeared under it.
Trees and greenery covering the mountain slopes were uprooted and sucked into the water column. The tsunami continually rushed from side to side inside the bay, covering the points of the shallows and sweeping away the forest covers of the high northern mountains on its way. There is no trace left of the La Gaussi spit, which separated the waters of the bay and Gilbert Bay. After everything had calmed down, on the shore one could see catastrophic cracks in the ground, severe destruction and rubble. The buildings erected by the fishermen were completely destroyed. The scale of the disaster was impossible to assess.
This wave claimed the lives of about three hundred thousand people. Only the longboat managed to escape, which by some incredible miracle was thrown out of the bay and thrown over the sandbank. Once on the other side of the mountain, the fishermen were left without a vessel, but were rescued two hours later. The bodies of the fishermen of another longboat were carried away into the abyss of water. They were never found.
Another terrible tragedy
Terrible destruction remained after the tsunami on December 26, 2004 for residents of the Indian Ocean coast. A powerful shock in the ocean caused a disastrous wave. In the depths of the Pacific Ocean, near the island of Sumatra, a fracture of the earth's crust occurred, which provoked a displacement of the bottom over a distance of more than 1000 kilometers. The largest wave that has ever covered the coast was formed from this fault. At first its height was no more than 60 centimeters. But it accelerated, and now a 20-meter shaft was rushing at an insane, unprecedented speed of 800 kilometers per hour towards the islands of Sumatra and Thailand to the east of India and Sri Lanka - to the west! In eight hours, a terrible tsunami, unprecedented in history, flew around the entire coast of the Indian Ocean, and in 24 hours, the entire World Ocean!
The greatest destruction occurred on the shores of Indonesia. The tidal wave buried cities and regions tens of kilometers deep. The islands of Thailand have become a mass grave for tens of thousands of people. Residents of coastal areas had no chance of salvation, since the water blanket held the cities under it for more than 15 minutes. Huge loss of life resulted from the natural disaster. Economic losses were also impossible to calculate. More than 5 million residents were forced to leave their homes, more than one million needed help, and two million people needed new housing. International organizations responded and helped the victims in every possible way.
Disaster in Prince William Sound
Severe, irreparable losses were caused by an earthquake on March 27, 1964 in Prince William Sound (Alaska) measuring 9.2 on the Richter scale. It covered a huge area of 800,000 square kilometers. Such a powerful shock from a depth of more than 20 kilometers can be compared with a simultaneous explosion of 12 thousand atomic bombs! The western coast of the United States of America was significantly damaged, which was literally covered by a huge tsunami. The wave reached as far as Antarctica and Japan. Villages and towns, enterprises, and the city of Veldez were wiped off the face of the earth.
The wave swept away everything that came in its way: dams, concrete blocks, houses, buildings, ships in the port. The wave height reached 67 meters! This, of course, is not the largest wave in the world, but it brought a lot of destruction. Fortunately, the deadly stream claimed the lives of approximately 150 people. The number of victims could have been much higher, but due to the sparse population of these places, only 150 local residents died. Considering the area and gigantic power of the stream, they had no chance of survival.
Great East Japan Earthquake
One can only imagine what force of nature destroyed the shores of Japan and brought irreparable losses to its inhabitants. After this disaster, the consequences will be felt for many years. At the junction of the world's two largest lithospheric plates, an earthquake measuring 9.0 on the Richter scale occurred, about twice the magnitude of the tremors caused by the 2004 Indian Ocean earthquake. A tragic event of enormous scale is also called the “Great East Japan Earthquake.” In just 20 minutes, a terrifying wave, the height of which exceeded 40 meters, reached the shores of Japan, where large number people.
About 25 thousand people became victims of the tsunami. This was the largest wave in the history of the Easterners. But this was only the beginning of the disaster. The scale of the tragedy grew every hour after the attack by the powerful flow of the Fokushima-1 nuclear power plant. The power plant system went out of operating mode due to tremors and shock waves. The failure was followed by a meltdown of the reactors in the power units. Today, a zone within a radius of tens of kilometers is a zone of exclusion and disaster. About 400 thousand buildings and structures were destroyed, bridges were destroyed, railway tracks, highways, airports, ports and shipping stations. It will take years to rebuild the country after the terrible disaster brought by the highest wave.
Disaster on the coast of Papua New Guinea
Another disaster struck the coast of Papua New Guinea in July 1998. The earthquake, measuring 7.1 on the measurement scale, triggered by a massive landslide, caused a wave more than 15 meters high, which killed more than 200 thousand people, leaving thousands more homeless on the island. Before the invasion of ocean water, there was a small bay here called Varupu, the waters of which washed two islands, where the Varupu people lived, worked and traded peacefully. Two powerful and unexpected impulses from underground occurred within 30 minutes of each other.
They set in motion a huge shaft, which caused strong waves that swept away several villages along a length of 30 kilometers from the face of New Guinea. Residents of seven more settlements needed assistance medical care and were hospitalized. The sea level in the capital of New Guinea, Rabaul, rose by 6 centimeters. A tidal wave of such magnitude has never been observed before, although in this region local residents often suffer from disasters such as tsunamis and earthquakes. A giant wave destroyed and carried under water an area of more than 100 square kilometers to a depth of 4 meters.
Tsunami in the Philippines
Exactly until August 16, 1976, the small island of Mindanao existed in the oceanic depression of Cotabato. It was the most southern, picturesque and exotic place among all the islands of the Philippines. Locals They could not at all predict that a terrible earthquake with a power of 8 points on the Richter scale would destroy this stunning place, washed by the seas on all sides. A huge force created a tsunami as a result of an earthquake.
The wave seemed to cut off the entire coastline of Mindanao. Not having time to escape, 5 thousand people died under the shelter of sea water. Approximately 2.5 thousand residents of the island were not found, 9.5 thousand received varying degrees of injury, more than 90 thousand lost their shelter and remained on the street. This was the strongest activity in the history of the Philippine Islands. Scientists who examined the details of the disaster found that the power of such a natural phenomenon caused movements of the water mass, which provoked a shift in the islands of Sulawesi and Borneo. It was the worst and most destructive event in the entire period of the existence of the island of Mindanao.
Why do Nazaré have the biggest waves in the world? July 15th, 2017
There is a place in the world from which photo and video reports of giant waves are often taken. For the last few years, records in Big Wave surfing for the largest wave taken (both by hand and with the help of a jet) have been set on the same wave, Nazaré. The first such record was set by Hawaiian surfer Garrett McNamara in 2011 - the wave height was 24 meters. Then, in 2013, he broke his record by riding a wave 30 meters high.
Why is this place the biggest waves in the world?
Let's first remember the mechanism of wave formation:
So, it all starts far, far away in the ocean, where the wind blows strong winds and storms rage. As we know from school course Geography, the wind blows from an area of high pressure to an area of low pressure. In the ocean, these areas are separated by many kilometers, so the wind blows over a very large area of the ocean, transferring part of its energy to the water due to the force of friction. Where this happens, the ocean is more like a bubbling soup - have you ever seen a storm at sea? It’s about the same there, only on a larger scale. There are small and large waves, all mixed up, superimposed on each other. However, the energy of water also does not stand still, but moves in a certain direction.
Due to the fact that the ocean is very, very large, and the waves different sizes moving with at different speeds, during the time until all this seething mess reaches the shore, it is “sifted”, some small waves add up with others into large ones, others, on the contrary, are mutually destroyed. As a result, what is called Groung Swell comes to the shore - smooth ridges of waves, divided into sets of three to nine with large intervals of calm between them.
However, not every swell is destined to become a surfable wave. Although, it would be more correct to say - not everywhere. In order for a wave to be caught, it must crash in a certain way. The formation of a wave for surfing depends on the structure of the bottom in coastal zone. The ocean is very deep, so the mass of water moves evenly, but as it approaches the shore, the depth begins to decrease, and the water, which moves closer to the bottom, for lack of any other way out, begins to rise to the surface, thereby raising waves. In the place where the depth, or rather shallowness, reaches a critical value, the rising wave can no longer become larger and collapses. The place where this happens is called the lineup, and that’s where the surfers sit, waiting for the right wave.
The shape of the wave directly depends on the shape of the bottom: the sharper the shallows become, the sharper the wave. Typically, the sharpest and even trumpeting waves are born where the height difference is almost instantaneous, for example, at the bottom of a huge rock or the beginning of a reef plateau.
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Where the drop is gradual and the bottom is sandy, the waves are flatter and slower. These are the waves that are best suited for learning to surf, which is why all surf schools conduct their first lessons for beginners on sandy beaches.
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Of course, there are also other factors that affect the waves, for example, the same wind: it can improve or worsen the quality of waves depending on the direction. In addition, there are so-called wind swells, these are waves that do not have time to be “sifted” by distance, since the storm is raging not so far from the coast.
So, now about the highest waves. Thanks to the winds, enormous energy is accumulated, which then moves towards the coast. As it approaches the shore, the oceanic swell transforms into waves, but unlike other places on our planet, a surprise awaits it off the coast of Portugal.
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The thing is that it is in the area of the city of Nazaré that the seabed is a huge canyon 5000 meters deep and 230 kilometers long. This means that the oceanic swell does not undergo changes, but reaches, as it is, all the way to the continent, falling on the coastal rocks with all its might. The height of a wave is usually measured as the distance from the crest to the base (where, incidentally, something like a trough is often sucked in, increasing the height compared to what it would be if measured by mean sea level at a given tide height).
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However, unlike waves such as Mavericks or Teahupoo, on Nazar the crest, even if it collapses, never hangs over the base; moreover, it is separated from the bottom point by about 40 meters along the horizontal axis. Due to spatial distortion of perspective, when looking from the front we see a body of water 30 meters high, technically it is even larger, but this is not the height of the wave. That is, strictly speaking, Nazaré is not a wave, but a water mountain, a pure oceanic swell, powerful and unpredictable.
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However, the fact that Nazaré is not exactly a wave does not make this spot any less scary or dangerous. Garrett McNamara says Nazaré is incredibly difficult to navigate. Usually three people help him in the water: one pulls him out on a jet to the line-up, accelerates him into the wave and does not swim far to make sure that everything is okay with the surfer. He is supported by a second jet, as well as a third one a little further away, whose driver is watching all three. Also, Garrett’s wife stands on the rock near the lighthouse and tells him on the radio what waves are coming and which ones can be taken. On the day he set his second record, not everything went smoothly. The first driver was knocked off the jet by a wave, so the second had to pull Garrett out of the foam, and the third hurried to help the first. Everything was done clearly and quickly, so no one was hurt.
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Garrett himself says the following: “of course, all these safety nets and technical devices in big wave surfing, it's kind of cheating. And in principle, you can do without them, but in this case the chances of dying are much higher. As for me personally, since I had a wife and children, I feel more responsibility for them and fear for my life, so I go to all technical lengths to make it as likely as possible to return home alive.”
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sources
Tsunami is one of the most terrifying natural phenomena. It is a wave formed as a result of “shaking” of the entire thickness of water in the ocean. Tsunamis are most often caused by underwater earthquakes.
Approaching the shore, the tsunami grows into a huge shaft tens of meters high and hits the shore with millions of tons of water. The largest tsunami in the world caused colossal destruction and led to the death of millions of people.
Krakatoa, 1883
This tsunami was not caused by an earthquake or landslide. The explosion of the Krakatoa volcano in Indonesia generated a powerful wave that swept along the entire coast of the Indian Ocean.Residents of fishing villages within a radius of about 500 km from the volcano had virtually no chance of survival. Victims were observed even in South Africa, on the opposite shore of the ocean. In total, 36.5 thousand people are considered dead from the tsunami itself.
Kuril Islands, 1952
The tsunami, triggered by a magnitude 7 earthquake, destroyed the city of Severo-Kurilsk and several fishing villages. Then the residents had no idea about the tsunami and after the earthquake stopped they returned to their homes, becoming victims of a 20-meter water shaft. Many were caught up in the second and third waves because they did not know that a tsunami is a series of waves. About 2,300 people died. Authorities Soviet Union decided not to report the tragedy in the media, so the disaster became known only decades later. 
The city of Severo-Kurilsk was subsequently moved to a higher place. And the tragedy became the reason for the organization in the USSR of a tsunami warning system and more active scientific research in seismology and oceanology.
Lituya Bay, 1958
An earthquake with a magnitude of more than 8 provoked a huge landslide with a volume of more than 300 million cubic meters, consisting of stones and ice from two glaciers. To these were added the waters of the lake, the shore of which collapsed into the bay. 
As a result, a gigantic wave was formed, reaching a height of 524 m! It swept across the bay, licking the vegetation and soil on the slopes of the bay like a tongue, completely destroying the spit that separated it from Gilbert Bay. This is the highest tsunami wave in history. The banks of Lituya were not inhabited, so only 5 fishermen became victims.
Chile, 1960
On May 22, the consequences of the Great Chilean Earthquake with a magnitude of 9.5 were a volcanic eruption and a tsunami 25 m high. Almost 6 thousand people died. 
But the rogue wave did not calm down there. At the speed of a jet plane, it crossed the Pacific Ocean, killing 61 people in Hawaii, and reached the shores of Japan. Another 142 people became victims of the tsunami, which occurred at a distance of more than 10 thousand km. After this, it was decided to warn about the danger of a tsunami even in the most remote areas of the coast that may be in the path of a deadly wave.
Philippines, 1976
The powerful earthquake caused a wave, the height of which seems to be unimpressive - 4.5 m. Unfortunately, the tsunami hit the low-lying coast for more than 400 miles. But the residents were not prepared for such a threat. The result is more than 5 thousand dead and about 2.5 thousand missing without a trace. Almost 100 thousand residents of the Philippines were left homeless, and many villages along the coastline were simply completely washed away along with their inhabitants. 
Papua New Guinea, 1998
The consequence of the earthquake on July 17 was a gigantic underwater landslide, which caused a 15-meter wave. And so the poor country suffered several natural disasters, more than 2,500 people died or went missing. And more than 10 thousand residents lost their homes and livelihoods. The tragedy became the impetus for studying the role of underwater landslides in causing tsunamis. 
Indian Ocean, 2004
December 26, 2004 is forever inscribed in blood in the history of Malaysia, Thailand, Myanmar and other countries on the Indian Ocean coast. On this day, the tsunami claimed the lives of about 280 thousand people, and according to unofficial data - up to 655 thousand. 
The underwater earthquake caused waves 30 m high that hit coastal areas within 15 minutes. The large number of deaths is due to several reasons. This high degree coastal population, lowland areas, large number of tourists on the beaches. But main reason– lack of an established tsunami warning system and poor awareness of people about safety measures.
Japan, 2011
The height of the wave resulting from the magnitude 9 earthquake reached 40 m. The whole world watched in horror the footage of the tsunami destroying coastal buildings, ships, cars...What determines the speed of a tsunami, what is it like?
The term tsunami is formed from two characters, read as "tsu", which means "harbour", and "nami" - a large wave. Although “big wave in the harbor” sounds somewhat descriptive, this term fits the essence of the phenomenon well, since tsunami waves greatly increase their height when approaching the shore.
Wave is oscillatory motion aquatic environment of the seas and oceans. Waves can be caused by the most for various reasons: wind, underwater earthquakes, volcanic eruptions, explosions, tidal forces of the Moon, ship movement, etc.
The main characteristics of any wave are: wave height - the vertical distance between the crest and the bottom of the wave, wave length - the horizontal distance between adjacent peaks or bottoms of the waves, period - the time interval between the arrival of two adjacent crests. The visible movement of a wave is often confused with the movements of water particles - while the wave crests move forward, the water particles describe vertical circles, only slightly deviating from their original position.
Wave diagram.
Parameters Wind waves Tsunami
Propagation speed up to 100 km/h up to 1000 km/h
Wavelength up to 0.5 km up to 1000 km
Period up to 20 seconds up to 2.5 hours
Penetration depth up to 300 m to the very bottom
Maximum (maximum) wave height in the open sea up to 30 m up to 2 m
Maximum (maximum) wave height off the coast up to 40 m up to 70 m
www.mstu.edu.ru/structure/faculties/ff/math/lab/prkat/cun_0.htm
The speed of tsunami propagation ranges from 50 to 1000 km/h and is directly proportional to the depth of the ocean at the site where the heterogeneity appears. In the open ocean, the wave is almost invisible, but when approaching the shore, due to braking on the bottom and shore, the wave slows down, the rear part catches up with the front, the height increases (up to 70 m), and a crest appears.
Tsunami waves are so long that they are not perceived as waves: their length ranges from 150 to 300 km. In the open sea, tsunamis are not very noticeable: their height is several tens of centimeters or, at most, a few meters. Having reached the shallow shelf, the wave becomes higher, rises and turns into a moving wall. Entering shallow bays or funnel-shaped river mouths, the wave becomes even higher. At the same time, it slows down and, like a giant shaft, rolls onto land. The greater the depth of the ocean, the higher the speed of the tsunami. With an average depth of the Pacific Ocean of about 4000 m, the theoretically calculated tsunami speed is 716 km/h. In reality, the speed of most tsunami waves ranges between 400 and 500 km/h, but there have been cases when they reached 1000 km/h.
www.mstu.edu.ru/structure/faculties/ff/math/lab/prkat/cun_0.htm.
