causes of tsunami essay

Essay on Tsunami for Students and Children

500+ words essay on tsunami.

Tsunami is a phenomenon where a series of strong waves that are responsible for the surge in water sometimes reach the heights in many meters. This is a natural disaster that is caused due to the volcano eruption in the ocean beds. Also, a phenomenon like landslides and earthquakes contributes to reasons for a tsunami. Like other natural disasters, the impact of the tsunami is also huge. It has been seen throughout history how disastrous the tsunami is. The essay on tsunami talks about various factors that contribute to the tsunami and the damage it causes to mankind. 

Essay on Tsunami

The disaster that is caused due to waves generated in the ocean because of the earthquake and whose main point is under the water is known as ‘Tsunami’. Also, the term tsunami is associated with tidal waves. Thus, a tsunami is also called as the series of ocean waves that have a very long wavelength. Because of the tsunami, there are strong waves of water is formed and this moves landwards. So, this causes inland movement of water which is very high and lasts for a long time. Thus, the impact of these waves is also very high. 

Greeks were the first people on Earth to claim the effects of the tsunami. They claim that tsunami is just like land earthquakes. Also, the only difference between tsunami and earthquake is that tsunami is caused in oceans. Thus, the scale and ferocity of the tsunami are almost impossible to control. 

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The History of Tsunami

The highest ever recorded tsunami was on 9th July 1958 in the record books. It took place in a bay which was located in the ligula bay along the coasts of Alaska. After the quake, a massive mass of rock fell into the bay waters from the cliff nearby. Thus, this created an impact and produced a wave that reached a height of 524 meters. Also, this is regarded as one of the highest recorded tsunami waves ever. 

The destructive waves responsible for the occurrence of tsunami is also produced in waters of bays or lakes. As this water approached the coast, it grows larger. However, the size of this wave is very low in deep-sea areas. Tsunami waves that are generated in the lakes or bays do not travel for a long distance. Thus, they are not as destructive as the ones produced in the ocean waters. There are various directions in which tsunami can travel from the main point. 

One similar devastating tsunami was experienced in India in 2004. However, the origin of this tsunami was located near Indonesia. Because of the tsunami, it was expected that a total of 2 lakh people lost their lives. The waves traveled extensively thousands of kilometers in countries like Thailand, India, Indonesia, Sri Lanka, Bangladesh, and the Maldives. 

Tsunamis occur mainly in the Pacific Ocean. There are very chances that they take place in the area where there are larger bodies. Coastlines and open bays next to very deep waters may help tsunami further into a step-like wave. 

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What is a tsunami?

A tsunami is a series of waves caused by earthquakes or undersea volcanic eruptions..

On September 29, 2009, a tsunami caused substantial damage and loss of life in American Samoa, Samoa, and Tonga. The tsunami was generated by a large earthquake in the Southern Pacific Ocean.

Did you know?

Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height. But as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases. The speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave. Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when reaching shallow waters. While tsunamis are often referred to as tidal waves, this name is discouraged by oceanographers because tides have little to do with these giant waves.

More Information

Tsunami "Fast Draw" Animation

Tracking Tsunamis (Ocean Today Video)

National Weather Service TsunamiReady ™

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• Forecast & Warning

The Tsunami Story

Tsunami is a set of ocean waves caused by any large, abrupt disturbance of the sea-surface. If the disturbance is close to the coastline, local tsunamis can demolish coastal communities within minutes. A very large disturbance can cause local devastation AND export tsunami destruction thousands of miles away. The word tsunami is a Japanese word, represented by two characters: tsu, meaning, "harbor", and nami meaning, "wave". Tsunamis rank high on the scale of natural disasters. Since 1850 alone, tsunamis have been responsible for the loss of over 420,000 lives and billions of dollars of damage to coastal structures and habitats. Most of these casualties were caused by local tsunamis that occur about once per year somewhere in the world. For example, the December 26, 2004, tsunami killed about 130,000 people close to the earthquake and about 58,000 people on distant shores. Predicting when and where the next tsunami will strike is currently impossible. Once the tsunami is generated, forecasting tsunami arrival and impact is possible through modeling and measurement technologies.

Generation. Tsunamis are most commonly generated by earthquakes in marine and coastal regions. Major tsunamis are produced by large (greater than 7 on the Richer scale), shallow focus (< 30km depth in the earth) earthquakes associated with the movement of oceanic and continental plates. They frequently occur in the Pacific, where dense oceanic plates slide under the lighter continental plates. When these plates fracture they provide a vertical movement of the seafloor that allows a quick and efficient transfer of energy from the solid earth to the ocean (try the animation in Figure 1). When a powerful earthquake (magnitude 9.3) struck the coastal region of Indonesia in 2004, the movement of the seafloor produced a tsunami in excess of 30 meters (100 feet) along the adjacent coastline killing more than 240,000 people. From this source the tsunami radiated outward and within 2 hours had claimed 58,000 lives in Thailand, Sri Lanka, and India.

Underwater landslides associated with smaller earthquakes are also capable of generating destructive tsunamis. The tsunami that devastated the northwestern coast of Papua New Guinea on July 17, 1998, was generated by an earthquake that registered 7.0 on the Richter scale that apparently triggered a large underwater landslide. Three waves measuring more than 7 meter high struck a 10-kilometer stretch of coastline within ten minutes of the earthquake/slump. Three coastal villages were swept completely clean by the deadly attack leaving nothing but sand and 2,200 people dead. Other large-scale disturbances of the sea -surface that can generate tsunamis are explosive volcanoes and asteroid impacts. The eruption of the volcano Krakatoa in the East Indies on Aug. 27, 1883 produced a 30-meter tsunami that killed over 36,000 people. In 1997, scientists discovered evidence of a 4km diameter asteroid that landed offshore of Chile approximately 2 million years ago that produced a huge tsunami that swept over portions of South America and Antarctica.

Figure 1. Click to see and animation of a tsunami generated by an earthquake.

Wave Propagation. Because earth movements associated with large earthquakes are thousand of square kilometers in area, any vertical movement of the seafloor immediately changes the sea-surface. The resulting tsunami propagates as a set of waves whose energy is concentrated at wavelengths corresponding to the earth movements (~100 km), at wave heights determined by vertical displacement (~1m), and at wave directions determined by the adjacent coastline geometry. Because each earthquake is unique, every tsunami has unique wavelengths, wave heights, and directionality (Figure 2 shows the propagation of the December 24, 2004 Sumatra tsunami.) From a tsunami warning perspective, this makes the problem of forecasting tsunamis in real time daunting.

Warning Systems. Since 1946, the tsunami warning system has provided warnings of potential tsunami danger in the pacific basin by monitoring earthquake activity and the passage of tsunami waves at tide gauges. However, neither seismometers nor coastal tide gauges provide data that allow accurate prediction of the impact of a tsunami at a particular coastal location. Monitoring earthquakes gives a good estimate of the potential for tsunami generation, based on earthquake size and location, but gives no direct information about the tsunami itself. Tide gauges in harbors provide direct measurements of the tsunami, but the tsunami is significantly altered by local bathymetry and harbor shapes, which severely limits their use in forecasting tsunami impact at other locations. Partly because of these data limitations, 15 of 20 tsunami warnings issued since 1946 were considered false alarms because the tsunami that arrived was too weak to cause damage.

Figure 2. Click to see the propagation of the December 24, 2004 Sumatra tsunami.

Forecasting impacts. Recently developed real-time, deep ocean tsunami detectors (Figure 3) will provide the data necessary to make tsunami forecasts. The November 17, 2003, Rat Is. tsunami in Alaska provided the most comprehensive test for the forecast methodology. The Mw 7.8 earthquake on the shelf near Rat Islands, Alaska, generated a tsunami that was detected by three tsunameters located along the Aleutian Trench-the first tsunami detection by the newly developed real-time tsunameter system. These real-time data combined with the model database (Figure 4) were then used to produce the real-time model tsunami forecast. For the first time, tsunami model predictions were obtained during the tsunami propagation, before the waves had reached many coastlines. The initial offshore forecast was obtained immediately after preliminary earthquake parameters (location and magnitude Ms = 7.5) became available from the West Coast/Alaska TWC (about 15-20 minutes after the earthquake). The model estimates provided expected tsunami time series at tsunameter locations. When the closest tsunameter recorded the first tsunami wave, about 80 minutes after the tsunami, the model predictions were compared with the deep-ocean data and the updated forecast was adjusted immediately. These offshore model scenarios were then used as input for the high-resolution inundation model for Hilo Bay. The model computed tsunami dynamics on several nested grids, with the highest spatial resolution of 30 meters inside the Hilo Bay (Figure 5). None of the tsunamis produced inundation at Hilo, but all of them recorded nearly half a meter (peak-to-trough) signal at Hilo gage. Model forecast predictions for this tide gage are compared with observed data in Figure 5. The comparison demonstrates that amplitudes, arrival time and periods of several first waves of the tsunami wave train were correctly forecasted. More tests are required to ensure that the inundation forecast will work for every likely-to-occur tsunami. When implemented, such forecast will be obtained even faster and would provide enough lead time for potential evacuation or warning cancellation for Hawaii and the U.S. West Coast.

Reduction of impact. The recent development of real-time deep ocean tsunami detectors and tsunami inundation models has given coastal communities the tools they need to reduce the impact of future tsunamis. If these tools are used in conjunction with a continuing educational program at the community level, at least 25% of the tsunami related deaths might be averted. By contrasting the casualties from the 1993 Sea of Japan tsunami with that of the 1998 Papua New Guinea tsunami, we can conclude that these tools work. For the Aonae, Japan case about 15% of the population at risk died from a tsunami that struck within 10 minutes of the earthquake because the population was educated about tsunamis, evacuation plans had been developed, and a warning was issued. For the Warapa, Papua New Guinea case about 40% of the at risk population died from a tsunami that arrived within 15 minutes of the earthquake because the population was not educated, no evacuation plan was available, and no warning system existed.

Eddie N. Bernard

References:

Bernard, E.N. (1998): Program aims to reduce impact of tsunamis on Pacific states. Eos Trans. AGU, 79(22), 258, 262-263.

Bernard, E.N. (1999): Tsunami. Natural Disaster Management, Tudor Rose, Leicester, England, 58-60.

Synolakis, C., P. Liu, G. Carrier, H. Yeh, Tsunamigenic Sea-Floor Deformations, Science, 278, 598-600, 1997.

Dudley, Walter C., and Min Lee (1998): Tsunami! Second Edition, University of Hawai'i Press, Honolulu, Hawaii.

What Is a Tsunami and What Causes Them? Research Paper

Introduction, plate tectonics, plate boundaries, how earthquake will generate tsunami.

Tsunamis are series of the ocean waves with very long wavelengths, hundreds of kilometers away, being brought about by various processes like sub marines, landslides, glacier calving, volcanic eruptions, meteorite impacts but greatly by earthquakes. It is formed in the ocean and big lakes.

Tsunami originated from the Japanese words ‘tsu’ meaning ‘harbor’ and ‘nami’ meaning ‘wave’ to make a ‘harbor wave’. Tsunamis have in the past and present brought catastrophic devastation to property and human death like in North East of Japan, on March 11, 2011. We shall dwell on the Shifts in the Tectonic plates as the reasoning behind the Tsunamis, but we have to understand the concept involved in the movement of the plate tectonics then how the earthquake will be generated to result into tsunami.

These are movements of the lithospheric plates. Tectonics is movement and deformation of the crust, which integrate the ancient theory of continental drift. Plates are the “lithospheric plates which are about 100 kilometers or more” (Earth Quake Museum, 2011, p. 1). Plate tectonics mostly produces earthquake.

It should be noted that, “the earth crust consist of plates sections that float on the molten rock of the mantle” (Earth Quake Museum, 2011, p. 1). The movement of the plates is due to the conventional current. Conventional current is brought about by relationship between the densities of the fluid to its temperature. We can say that convectional current is the flow that transfers heat within a fluid by setting in motion by the heating and cooling of the fluid which changes in its density and continues as long as it heats.

The magma containing material at very high temperatures “rises and spreads on the surfaces creating a new crust which spreads out forming a new plate, until it meets other plates” (Earth Quake Museum, 2011, p. 1). After such a mechanism, “then one of the plates will pushed down into the inferior of the earth and reabsorbed in the mantle; plates can also compress to push up the mountains when they collide or move sideways along the transform faults” (Earth Quake Museum, 2011, p. 1).

The process of plates’ movements is a bit detailed as explained by the Geography site below:

One of the most famous examples of plates sliding past each other is the San Andreas Fault in California. Here the two plates, the Pacific plate and the North American plate both move in a roughly in the northwesterly direction, but one is moving faster than the other. The San Francisco area is prone to many small earthquakes every year as the two plates grind against each other. (Geography site, 2006, p. 1)

The above diagram shows, “Divergent Boundaries occur at Oceanic Ridges, where new Oceanic lithosphere is formed and moves away from the ridge in opposite directions” (The Earth and Beyond, 2011, p. 1).

Shown above: “convergent Boundaries occur where oceanic lithosphere is pushed back into the mantle, marked by oceanic trenches and subduction zones” (The Earth and Beyond, 2011, p. 1).

Two types are possible –

“When two plates of oceanic lithosphere converge oceanic lithosphere is subducted beneath oceanic lithosphere; when ocean lithosphere runs into a plate with continental lithosphere, the oceanic lithosphere is subducted beneath the continental lithosphere” (The Earth and Beyond, 2011, p. 1).

“Transform Boundaries occur where two plates slide past one another horizontally; the San Andreas Fault, in California is a transform fault” (The Earth and Beyond, 2011, p. 1).

“Continental rifting may create a new divergent margin and evolve into an oceanic ridge, such as is occurring in East Africa and between the African Plate and the Arabian Plate” (The Earth and Beyond, 2011, p. 1).

It has been shown that the plates play very significant role in making the earth crust unstable:

Continental lithosphere collide to join two plates together, such as has occurred recently where the Indian Plate has collided with the Eurasian Plate to form the Himalaya Mountains. Plate tectonics explains why earthquakes occur where they do, why volcanoes occur where they do, how mountain ranges form, as well as many other aspects of the Earth. It is such an important theory in understanding how the Earth works. (The Earth and Beyond, 2011, p. 1)

After fault has been created the earthquake will occur on it due to the massive violent movement as the two plates compress one another or override one another causing heavy pressure on the underlying rock. This causes vibrations or shockwaves to go through ground. As the solid rock plate moves up beneath the sea, “there is a sudden movement within the crust or mantle and concentric shock waves moves out of that point” (Geography site, 2006, p. 1).

The point of origin is referred as the focus, where in a radius of around 250 miles the effect is greatly felt, and the point directly above the surface is called the epicenter (Geography site, 2006).

A Tsunami is formed when “the sea floor abruptly deforms and vertically displaces the overlying water” (Geography site, 2006, p. 1). Earth’s crust deforms from at points below the ocean consequently disturbing the overlying mass of water. The process continues as thus:

The water above is displaced from its equilibrium position. The waves will be as result of the displacement of the water mass, which act under influence of gravity, to regain its equilibrium position. The potential energy that results from the uplifting or pushing of the water above mean level is then transferred to horizontal propagation of tsunami wave which possess the kinetic energy. (Tsunami, 2011, p. 1)

Tsunamis will results when a large sea floor elevate. Within several minute of earthquake, the initial, panel 1, is split into a tsunami that travels out of the deep ocean and another travelling to the nearby coast (Tsunami, 2011).

The tsunami will be greatly affected as it travels through the ocean where the rate at which the wave loses its energy is related to its wavelength. At deep waters the wave will travel at a very high velocity and as it approached the shoe or as the depth decreases the speed of the wave decreases; however the energy of the wave remains constant.

From the above study, tsunamis are produced or generated by the plate tectonic beside where the movement of the tectonics due to convectional current due to the heat coming from the earth center. This produces the movement of the plate where one plate moves toward the other and collide resulting in the faults being formed. This movement causes a ground shaking movement resulting into elastic waves travelling through the solid earth where one plate is emerged above the other and this causes an upward movement.

The upward movement causes the water above to be displaced, pushing a large volume of water upwards and the potential energy involved is transformed to horizontal kinetic energy which is massive causing formation of a wave of water which is the tsunami. For the last tsunamis they have occurred through this method.

Geography site. (2006). What causes an earthquake? Web.

The Earth and beyond. (2011). The earth and beyond, plate tectonics . Web.

The Earthquake Museum. (2011). What causes earthquakes? Web.

Tsunami. (2011). Tsunamis . Web.

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Tsunami Generation: Earthquakes

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Earth's surface is made up of tectonic plates, which are large slabs of solid rock that fit together like puzzle pieces. These plates meet at plate boundaries and are in constant motion.

Where the surfaces of these plates catch and lock along their boundary, stress builds up as the rest of the plates continue to move. This takes place over long periods of time.

When the stress becomes too great, the plates suddenly slip past one another, releasing tremendous amounts of energy, which causes the earth to shake and crack.

These cracks are called faults. Plate boundaries are made up of many faults, and this is where most earthquakes occur.

Faults can also occur far from plate boundaries, but earthquakes in these locations (intraplate earthquakes) are much less frequent. The scientific community is working to better understand these types of faults.

Earthquakes generally occur on three types of faults: normal, strike-slip, and reverse (or thrust).

Tsunamis can be generated by earthquakes on all of these faults, but most tsunamis, and the largest, result from earthquakes on reverse faults. These tsunami-generating earthquakes originate mainly in subduction zones, where tectonic plates collide and one is forced under the other.

Take it to the MAX!   Plate Tectonics and Earthquakes

If big enough and close enough to the ocean floor, the energy from such an earthquake can cause the ocean floor to suddenly rise (uplift) or fall (subside). This sudden vertical displacement of the ocean floor is what typically sets a tsunami in motion.

As the ocean floor rises or falls, so too does the water above it. As the water moves up and down to regain its balance, a tsunami is born.

Not all earthquakes cause tsunamis. Key earthquake characteristics that contribute to tsunami generation are location, magnitude (size), and depth.

Most tsunamis are generated by earthquakes with magnitudes over 7.0 that occur under or very near the ocean and less than 100 kilometers (62 miles) below Earth's surface (earthquakes deeper than this are unlikely to displace the ocean floor).

Generally, an earthquake must exceed magnitude 8.0 to generate a dangerous distant tsunami. The amount of movement of the ocean floor, the size of the area over which an earthquake occurs, and the depth of the water above the earthquake are also important factors in the size of a resulting tsunami.

Most of the tsunamis (89%) in the  Global Historical Tsunami Database  were generated by large earthquakes or landslides caused by earthquakes.

In addition to the previously highlighted tsunamis (2004 and 2011), other examples of earthquake-generated tsunamis include:

• November 1, 1755, Lisbon, Portugal - A magnitude 8.5 (estimated) earthquake in the Atlantic Ocean generated a tsunami that affected the coasts of Portugal, Spain, North Africa, and the Caribbean. The earthquake and tsunami killed an estimated 50,000 people and caused widespread destruction.
• January 26, 1700, Cascadia Subduction Zone - A magnitude 9.0 (estimated) earthquake generated a tsunami that inundated the coasts of Cascadia (a region that includes northern California, Oregon, Washington, and southern British Columbia) as well as coastal villages across the Pacific Ocean in Japan. Today, the Cascadia subduction zone is considered one of the largest U.S. tsunami threats.

To learn more about earthquakes, visit the  U.S. Geological Survey's Earthquake Hazards Program .

What causes a tsunami? An ocean scientist explains the physics of these destructive waves

Assistant Professor of Climate Science, Brandeis University

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Sally Warner has received funding from the National Science Foundation and the Office of Naval Research.

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On Jan. 15, 2022, the Hunga Tonga-Hunga Ha’apai volcano in Tonga erupted, sending a tsunami racing across the Pacific Ocean in all directions.

As word of the eruption spread, government agencies on surrounding islands and in places as far away as New Zealand, Japan and even the U.S. West Coast issued tsunami warnings. Only about 12 hours after the initial eruption, tsunami waves a few feet tall hit California shorelines – more than 5,000 miles away from the eruption.

I’m a physical oceanographer who studies waves and turbulent mixing in the ocean. Tsunamis are one of my favorite topics to teach my students because the physics of how they move through oceans is so simple and elegant.

Waves that are a few feet tall hitting a beach in California might not sound like the destructive waves the term calls to mind, nor what you see in footage of tragic tsunamis from the past . But tsunamis are not normal waves, no matter the size. So how are tsunamis different from other ocean waves? What generates them? How do they travel so fast? And why are they so destructive?

Deep displacement

Most waves are generated by wind as it blows over the ocean’s surface, transferring energy to and displacing the water. This process creates the waves you see at the beach every day.

Tsunamis are created by an entirely different mechanism. When an underwater earthquake, volcanic eruption or landslide displaces a large amount of water, that energy has to go somewhere – so it generates a series of waves. Unlike wind-driven waves where the energy is confined to the upper layer of the ocean, the energy in a series of tsunami waves extends throughout the entire depth of the ocean. Additionally, a lot more water is displaced than in a wind-driven wave.

Imagine the difference in the waves that are created if you were to blow on the surface of a swimming pool compared to the waves that are created when someone jumps in with a big cannonball dive. The cannonball dive displaces a lot more water than blowing on the surface, so it creates a much bigger set of waves.

Earthquakes can easily move huge amounts of water and cause dangerous tsunamis. Same with large undersea landslides. In the case of the Tonga tsunami, the massive explosion of the volcano displaced the water. Some scientists are speculating that the eruption also caused an undersea landslide that contributed to the large amount of displaced water. Future research will help confirm whether this is true or not.

Tsunami waves travel fast

No matter the cause of a tsunami, after the water is displaced, waves propagate outward in all directions – similarly to when a stone is thrown into a serene pond.

Because the energy in tsunami waves reaches all the way to the bottom of the ocean, the depth of the sea floor is the primary factor that determines how fast they move. Calculating the speed of a tsunami is actually quite simple. You just multiply the depth of the ocean – 13,000 feet (4,000 meters) on average – by gravity and take the square root. Doing this, you get an average speed of about 440 miles per hour (700 kilometers per hour). This is much faster than the speed of typical waves, which can range from about 10 to 30 mph (15 to 50 kph).

This equation is what oceanographers use to estimate when a tsunami will reach faraway shores. The tsunami on Jan. 15 hit Santa Cruz, California, 12 hours and 12 minutes after the initial eruption in Tonga. Santa Cruz is 5,280 miles (8,528 kilometers) from Tonga, which means that the tsunami traveled at 433 mph (697 kph) – nearly identical to the speed estimate calculated using the ocean’s average depth.

Destruction on land

Tsunamis are rare compared to ubiquitous wind-driven waves, but they are often much more destructive. The 2004 Indian Ocean tsunami killed 225,000 people. More than 20,000 lost their lives in the 2011 Japan tsunami.

What makes tsunamis so much more destructive than normal waves?

In the open ocean, tsunami waves can be small and may even be undetectable by a boat at the surface. But as the tsunami approaches land, the ocean gets progressively shallower and all the wave energy that extended thousands of feet to the bottom of the deep ocean gets compressed. The displaced water needs to go somewhere. The only place to go is up, so the waves get taller and taller as they approach shore.

When tsunamis get to shore, they often do not crest and break like a typical ocean wave. Instead, they are more like a large wall of water that can inundate land near the coast. It is as if sea level were to suddenly rise by a few feet or more. This can cause flooding and very strong currents that can easily sweep people, cars and buildings away.

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Luckily, tsunamis are rare and not nearly as much of a surprise as they once were. There is now an extensive array of bottom pressure sensors, called DART buoys , that can sense a tsunami wave and allow government agencies to send warnings prior to the arrival of the tsunami.

If you live near a coast – especially on the Pacific Ocean where the vast majority of tsunamis occur – be sure to know your tsunami escape route for getting to higher ground, and listen to tsunami warnings if you receive one.

The eruption of the Hunga Tonga-Hunga Ha’apai volcano severed the main communication cable that connects the people of Tonga to the rest of the world. While the science of tsunamis can be fascinating, these are serious natural disasters. Only a few deaths have been reported so far from Tonga, but many people are missing and the true extent of the damage from the tsunami is still unknown.

• Earthquakes
• Pacific Ocean
• Tsunami warning
• Hunga Tonga

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Cause & Effect Essay: Tsunamis

The movie “The Impossible” starring Ewan McGregor and Naomi Watts documents an event that was rare, tragic, devastating – but far from impossible. The movie is a dramatization of a real event that shocked the entire world. In 2004, fourteen countries were effected by a powerful natural event that launched a 98 foot tidal wave and killed 230, 000 people. Countries such as Sri Lanka, Thailand, and Indonesia were devastated. But what was this powerful natural event? A tsunami. And not just any tsunami, but the worst single tsunami in recorded history. Tsunamis, or “seismic sea waves”, as they are sometimes called, can be devastating. But what causes these extreme weather phenomena? And how do they affect the world?

Tsunamis can be caused by landslides or volcanic eruptions that occur on the ocean floor. Rarely, they can be triggered by large meteorite impacts. But most tsunamis are caused by an earthquake. Luckily, not all earthquakes cause tsunamis. They must be large earthquakes that occur under or near the ocean, and create movement under the sea floor. Earthquakes themselves are caused by the meeting of the earth’s tectonic plates along ‘faults’ or ‘fault lines’. When these earthquakes occur at a submarine level, the vibrations cause the ocean water to ripple and move. And the bigger the earthquake.. the larger the results.

A tsunami is, in essence, an enormous wave. Or, to be more specific, a series of giant waves. They most often occur in the Pacific Ocean due to the amount of ocean trenches, mountain chains, and volcanoes that line the ocean floor. There are a total of 452 volcanoes in this titled, “Ring of Fire” that can erupt at any time.

The problem with tsunamis is the fact that their effects are somewhat unpredictable. They can strike hundreds of kilometers away from where the initial earthquake took place. Generally, places such as Alaska, Japan, the Philippines, and the west coast of the United States are at the greatest risk. Tsunamis reach coastal areas the quickest, landing enormous waves on the shore in a manner that can tear buildings apart and sweep people and vehicles away. They flood areas quickly and have an energy that is often equivocated to the energy from multiple blasts of TNT. Tsunamis cause many people to lose their homes and places of business, and cost governments millions of dollars in repairs and assistance. Contaminated water needs to be dealt with and people need food and medical care.

Earthquakes in themselves are devastating. But for coastal areas, a far greater danger can strike later: the dreaded tsunami. With the speed of a tornado and the blast of a volcano eruption, a tsunami can displace people, elements of nature, and monuments of human construction. More effort needs to be put into detection systems so that people can better prepare for the impact that a tsunami can have.

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Essay on Tsunami

Students are often asked to write an essay on Tsunami in their schools and colleges. And if you’re also looking for the same, we have created 100-word, 250-word, and 500-word essays on the topic.

Let’s take a look…

100 Words Essay on Tsunami

What is a tsunami.

A tsunami is a series of powerful waves caused by the displacement of a large volume of water. This usually happens due to earthquakes, volcanic eruptions, or underwater landslides.

How Does a Tsunami Form?

When the sea floor abruptly deforms, it displaces the overlying water, triggering a tsunami. The waves travel across the ocean at high speeds.

Effects of a Tsunami

Tsunamis can cause mass destruction when they hit land. They can flood cities, destroy buildings, and take lives. It’s important to have early warning systems to minimize damage.

Understanding tsunamis helps us prepare and mitigate their harmful effects.

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250 Words Essay on Tsunami

Introduction.

Tsunamis, deriving from the Japanese words ‘tsu’ meaning harbor and ‘nami’ meaning wave, are a series of powerful water waves caused by the displacement of a large volume of a body of water. They are known for their destructive power and unpredictability, posing a significant threat to coastal communities.

Causes of Tsunamis

Tsunamis are typically triggered by seismic activities beneath the ocean floor. These include earthquakes, volcanic eruptions, or landslides. The energy released during these events displaces the overlying water column, generating waves that can travel across oceans at high speeds.

Characteristics and Impact

Unlike regular waves, tsunami waves involve the movement of the entire water column from the sea surface to the seabed. This attribute contributes to their long wavelengths and high energy, enabling them to travel vast distances. Upon reaching shallow waters, their speed decreases, causing the wave height to increase dramatically, often resulting in widespread destruction when they hit land.

Prevention and Mitigation

While tsunamis cannot be prevented, their impact can be mitigated through early warning systems, coastal zone management, and community preparedness. Technological advancements have made it possible to detect seismic activities and issue timely alerts, thereby saving lives.

Tsunamis, while a fascinating natural phenomenon, are a stark reminder of nature’s power. Understanding their causes and characteristics is crucial in developing effective mitigation strategies, thereby reducing their devastating impacts on human lives and the environment.

500 Words Essay on Tsunami

Tsunamis, often referred to as seismic sea waves, are a series of ocean waves caused by any large-scale disturbance of the sea surface. These disturbances can include earthquakes, volcanic eruptions, landslides or even meteorite impacts in the ocean. Tsunamis are not regular sea waves but energy waves, often caused by seismic activities beneath the ocean floor. Their impact on human lives and the environment can be devastating, emphasizing the importance of understanding and predicting these natural disasters.

The Mechanics of a Tsunami

Tsunamis are initiated by a sudden displacement of the sea floor due to geological activities like earthquakes. This displacement results in a vertical shift of the overlying water column, creating a series of waves that radiate outwards from the point of origin. The speed of a tsunami is determined by the depth of water, with deeper waters facilitating faster wave speeds.

In the open ocean, these waves may be just a few centimeters high, but their wavelength, or the distance between successive crests, can span hundreds of kilometers. As these waves approach coastal areas, the shallowing sea floor compresses the wave energy, causing the wave to increase dramatically in height.

Impact and Consequences

The destructive power of a tsunami comes from the massive amount of water that it can move and the consequent flooding. When a tsunami reaches the shore, it can cause immense damage to structures, erode beaches and embankments, destroy vegetation, and severely impact both terrestrial and marine life.

The human toll can be equally devastating. Tsunamis can lead to loss of life, displacement of people, and economic damage. The aftermath of a tsunami often includes public health crises, with the spread of waterborne diseases and psychological trauma among survivors.

Unfortunately, tsunamis cannot be prevented as they are triggered by natural geological processes. However, their impact can be mitigated through early warning systems, community preparedness, and intelligent coastal management.

Tsunami early warning systems, comprising seismographs and sea level monitoring stations, can provide critical minutes to hours of warning. This allows people in the path of a tsunami to seek higher ground. Community preparedness involves education about tsunami risks, evacuation routes, and drills. Intelligent coastal management can include the construction of seawalls, planting of mangroves to absorb wave energy, and zoning laws to prevent construction in high-risk areas.

Tsunamis, while a fascinating demonstration of the power of nature, are a sobering reminder of our vulnerability to natural disasters. As our understanding of these phenomena grows, so too does our ability to protect ourselves and our communities. The implementation of early warning systems, public education, and intelligent coastal management are key components in reducing the devastating impact of these ocean giants. Through continued research and community resilience, we can mitigate the effects of tsunamis and safeguard our future against these powerful sea waves.

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