essay on prevention of tsunami

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. 

Get the huge list of more than 500 Essay Topics and Ideas

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. 

Customize your course in 30 seconds

Which class are you in.

• Travelling Essay
• Picnic Essay
• Our Country Essay
• My Parents Essay
• Essay on Favourite Personality
• Essay on Memorable Day of My Life
• Essay on Knowledge is Power
• Essay on Gurpurab
• Essay on My Favourite Season
• Essay on Types of Sports

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Download the App

• Tools and Resources
• Customer Services
• Case Studies
• Climate Change
• Coastal Storm Surge
• Convective Storms
• Cultural Perspectives
• Development
• Earthquakes
• Economic Analysis of Natural Hazards
• Exposed Populations
• Extreme Temperatures
• Gender Issues
• Glacial Lake Outburst (GLOFs)
• Health Impacts
• Infrastructure
• Legal Issues
• Mass Movement
• Policy and Governance
• Population Movements
• Preparedness
• Risk Assessment
• Risk Communication and Warnings
• Risk Management
• Sea Level Rise
• Space Weather
• Tropical Storms
• Urban Issues
• Volcanic Activity
• Vulnerability
• Winter Storms / Blizzards
• Share This Facebook LinkedIn Twitter

Article contents

Tsunami preparedness and mitigation strategies.

• James D. Goltz James D. Goltz University of Colorado Boulder, Natural Hazards Center
•  and  Katsuya Yamori Katsuya Yamori Kyoto University, Disaster Prevention Research Institute
• https://doi.org/10.1093/acrefore/9780199389407.013.324
• Published online: 28 February 2020

Tsunamis are natural hazards that have caused massive destruction and loss of life in coastal areas worldwide for centuries. Major programs promoting tsunami safety, however, date from the early 20th century and have received far greater emphasis following two major events in the opening decade of the 21st century: the Indian Ocean Tsunami of December 26, 2004, and the Great East Japan Earthquake and Tsunami of March 11, 2011. In the aftermath of these catastrophic disasters, warning systems and the technologies associated with them have expanded from a concentration in the Pacific Ocean to other regions with significant tsunami vulnerability. Preparedness and hazard mitigation programs, once the province of wealthier nations, are now being shared with developing countries. While warning systems and tsunami mapping and modeling are basic tools in promoting tsunami safety, there are a number of strategies that are essential in protecting lives and property in major tsunami events. Preparedness strategies consist of tsunami awareness and education and actions that promote response readiness. These strategies should provide an understanding of how tsunamis occur, where they occur, how to respond to warnings or natural signs that a tsunami may occur, and what locations are safe for evacuation. Hazard mitigation strategies are designed to reduce the likelihood that coastal populations will be impacted by a tsunami, typically through engineered structures or removing communities from known tsunami inundation zones. They include natural or constructed high ground for evacuation, structures for vertical evacuation (either single purpose structures specifically for tsunami evacuation or existing buildings that are resistant to tsunami forces), seawalls, breakwaters, forest barriers, and tsunami river gates. Coastal jurisdictions may also use land-use planning ordinances or coastal zoning to restrict development in areas of significant risk of tsunami inundation. The relative efficacy of these strategies and locations where they have been implemented will be addressed, as will the issues and challenges regarding their implementation.

• preparedness
• earthquakes

You do not currently have access to this article

Please login to access the full content.

Access to the full content requires a subscription

Printed from Oxford Research Encyclopedias, Natural Hazard Science. Under the terms of the licence agreement, an individual user may print out a single article for personal use (for details see Privacy Policy and Legal Notice).

date: 25 April 2024

• Cookie Policy
• Privacy Policy
• Legal Notice
• Accessibility
• [66.249.64.20|81.177.182.174]
• 81.177.182.174

Character limit 500 /500

• ENVIRONMENT

Tsunami Facts: How They Form, Warning Signs, and Safety Tips

National Geographic News looks at how the killer waves are caused, what the warning signs are, and how to respond when a tsunami threatens.

• A tsunami is a series of great sea waves caused by an underwater earthquake, landslide, or volcanic eruption. More rarely, a tsunami can be generated by a giant meteor impact with the ocean.
• Scientists have found traces of an asteroid-collision event that they say would have created a giant tsunami that swept around the Earth several times, inundating everything except the tallest mountains 3.5 billion years ago. The coastline of the continents was changed drastically and almost all life on land was exterminated.
• Tsunami (pronounced soo-NAH-mee) is a Japanese word. Tsunamis are fairly common in Japan, and many thousands of Japanese have been killed by them in recent centuries.
• An earthquake generates a tsunami if it is of sufficient force and there is violent movement of the earth to cause substantial and sudden displacement of a massive amount of water.
• A tsunami is not a single wave but a series of waves, also known as a wave train. The first wave in a tsunami is not necessarily the most destructive. Tsunamis are not tidal waves.
• Tsunami waves can be very long (as much as 60 miles, or 100 kilometers) and be as far as one hour apart. They are able to cross entire oceans without great loss of energy. The Indian Ocean tsunami traveled as much as 3,000 miles (nearly 5,000 kilometers) to Africa, arriving with sufficient force to kill people and destroy property.
• Scientists say that a great earthquake of magnitude 9 struck the Pacific Northwest in 1700 and created a tsunami that caused flooding and damage on the Pacific coast of Japan.

As Fast as a Commercial Jet

• Where the ocean is deep, tsunamis can travel unnoticed on the surface at speeds up to 500 miles an hour (800 kilometers an hour), crossing an ocean in a day or less. Scientists are able to calculate arrival times of tsunamis in different parts of the world based on their knowledge of water depths, distances, and when the event that generated them occurred.
• A tsunami may be less than a foot (30 centimeters) in height on the surface of the open ocean, which is why they are not noticed by sailors. But the powerful shock wave of energy travels rapidly through the ocean as fast as a commercial jet. Once a tsunami reaches shallow water near the coast, it is slowed down. The top of the wave moves faster than the bottom, causing the sea to rise dramatically.
• Geological features such as reefs, bays, river entrances, and undersea formations may dissipate the energy of a tsunami. In some places a tsunami may cause the sea to rise vertically only a few inches or feet. In other places tsunamis have been known to surge vertically as high as 100 feet (30 meters). Most tsunamis cause the sea to rise no more than 10 feet (3 meters).
• Geological features such as reefs, bays, river entrances, and undersea formations may dissipate the energy of a tsunami. In some places a tsunami may cause the sea to rise vertically only a few inches or feet. In other places tsunamis have been known to surge vertically as high as 100 feet (30 meters).
• Most tsunamis cause the sea to rise no more than 10 feet (3 meters). The Indian Ocean tsunami of December 2004 caused waves as high as 30 feet (9 meters) in some places, according to news reports. In other places witnesses described a rapid surging of the ocean.
• Flooding can extend inland by a thousand feet (300 meters) or more. The enormous energy of a tsunami can lift giant boulders, flip vehicles, and demolish houses. Knowledge of the history of tsunamis in your area is a good indicator of what is likely to happen in a future tsunami event.
• Tsunamis do not necessarily make their final approach to land as a series of giant breaking waves. They may be more like a very rapidly rising tide. This may be accompanied by much underwater turbulence, sucking people under and tossing heavy objects around. Entire beaches have been stripped away by tsunamis.
• Many witnesses have said a tsunami sounds like a freight train.The 2004 Indian Ocean tsunami could rank as the most devastating on record. More than 200,000 people lost their lives, many of them washed out to sea.
• The most damaging tsunami on record before 2004 was the one that killed an estimated 40,000 people in 1782 following an earthquake in the South China Sea. In 1883 some 36,500 people were killed by tsunamis in the South Java Sea, following the eruption of Indonesia's Krakatoa volcano. In northern Chile more than 25,000 people were killed by a tsunami in 1868.
• The Pacific is by far the most active tsunami zone, according to the U.S. National Oceanic and Atmospheric Administration (NOAA). But tsunamis have been generated in other bodies of water, including the Caribbean and Mediterranean Seas, and the Indian and Atlantic Oceans. North Atlantic tsunamis included the tsunami associated with the 1775 Lisbon earthquake that killed as many as 60,000 people in Portugal, Spain, and North Africa. This quake caused a tsunami as high as 23 feet (7 meters) in the Caribbean.
• The Caribbean has been hit by 37 verified tsunamis since 1498. Some were generated locally and others were the result of events far away, such as the earthquake near Portugal. The combined death toll from these Caribbean tsunamis is about 9,500.
• Large tsunami waves were generated in the Marmara Sea in Turkey after the Izmit earthquake of 1999.

You May Also Like

3,600-year-old tsunami ‘time capsule’ sheds light on one of humanity’s greatest disasters

A tsunami could wipe this Norwegian town off the map. Why isn’t everyone leaving?

Warning signs.

• An earthquake is a natural tsunami warning. If you feel a strong quake do not stay in a place where you are exposed to a tsunami. If you hear of an earthquake be aware of the possibility of a tsunami and listen to the radio or television for additional information. Remember that an earthquake can trigger killer waves thousands of miles across the ocean many hours after the event generated a tsunami.
• Witnesses have reported that an approaching tsunami is sometimes preceded by a noticeable fall or rise in the water level. If you see the ocean receding unusually rapidly or far it's a good sign that a big wave is on its way. Go to high ground immediately.
• Many people were killed by the Indian Ocean tsunami because they went down to the beach to view the retreating ocean exposing the seafloor. Experts believe that a receding ocean may give people as much as five minutes' warning to evacuate the area.
• Remember that a tsunami is a series of waves and that the first wave may not be the most dangerous. The danger from a tsunami can last for several hours after the arrival of the first wave. A tsunami wave train may come as a series of surges that are five minutes to an hour apart. The cycle may be marked by a repeated retreat and advance of the ocean.
• Stay out of danger until you hear it is safe. Survivors of the Indian Ocean tsunami reported that the sea surged out as fast and as powerfully as it came ashore. Many people were seen being swept out to sea when the ocean retreated.
• A tsunami surge may be small at one point of the shore and large at another point a short distance away. Do not assume that because there is minimal sign of a tsunami in one place it will be like that everywhere else.
• Tsunamis can travel up rivers and streams that lead to the ocean. Stay away from rivers and streams that lead to the ocean as you would stay away from the beach and ocean if there is a tsunami.
• It's always a good idea to keep a store of emergency supplies that include sufficient medications, water, and other essentials sufficient for at least 72 hours. Tsunami, earthquake, hurricane—an emergency can develop with little or no warning.

Advice for Sailors

Free bonus issue.

• NOAA advises that since tsunami wave activity is imperceptible in the open ocean, vessels should not return to port if they are at sea and a tsunami warning has been issued for the area. Tsunamis can cause rapid changes in water level and unpredictable, dangerous currents in harbors and ports. Boat owners may want to take their vessels out to sea if there is time and if the sailors are allowed to do so by port authorities. People should not stay on their boats moored in harbors. Tsunamis often destroy boats and leave them wrecked above the normal waterline.
• Heightened awareness of the potential for a tsunami to inundate the U.S. western coastline has caused NOAA, the U.S. Geological Survey, and the Federal Emergency Management Administration to initiate a program to predict tsunamis more accurately. As a tsunami traverses the ocean, a network of sensitive recorders on the sea floor measures pressure changes in the overhead water, sending the information to sensors on buoys, which in turn relay the data to satellites for immediate transmission to warning centers.
• The Tsunami Warning System (TWS) in the Pacific, composed of 26 member countries, monitors seismological and tidal stations throughout the Pacific region. The system evaluates potentially tsunami-causing earthquakes and issues tsunami warnings. An international warning system for tsunamis in the Indian Ocean was launched in June 2006.
• Use your common sense. If you feel or hear of a strong earthquake do not wait for an official tsunami warning. Tell your family and friends to join you in leaving for high ground.

Related Topics

• NATURAL DISASTERS AND HAZARDS

Japan's 2011 megaquake left a scar at the bottom of the sea. Scientists finally explored it.

This summer's extreme weather is a sign of things to come

The island of Santorini is hiding an explosive secret

A rare and puzzling ‘domino effect’ triggered 4 powerful quakes in Afghanistan

What was lost in Lahaina, a glittering jewel of the Hawaiian Kingdom

• Environment
• Perpetual Planet
• History & Culture

History & Culture

• History Magazine
• Mind, Body, Wonder
• Paid Content
• Terms of Use
• Privacy Policy
• Your US State Privacy Rights
• Children's Online Privacy Policy
• Interest-Based Ads
• About Nielsen Measurement
• Do Not Sell or Share My Personal Information
• Nat Geo Home
• Attend a Live Event
• Book a Trip
• Inspire Your Kids
• Shop Nat Geo
• Visit the D.C. Museum
• Learn About Our Impact
• Support Our Mission
• Advertise With Us
• Customer Service
• Renew Subscription
• Manage Your Subscription
• Work at Nat Geo
• Sign Up for Our Newsletters
• Contribute to Protect the Planet

Copyright © 1996-2015 National Geographic Society Copyright © 2015-2024 National Geographic Partners, LLC. All rights reserved

Image source: Australian Bureau of Meteorology

• Earth & environment

Protecting people from tsunami

What causes tsunami and how can we prepare?

Expert reviewers

Dr Hannah Power

University of Newcastle

Community Safety and Earth Monitoring Division at Geoscience Australia

Australian Bureau of Meteorology

•  A tsunami is a series of waves that result from the displacement of large amounts of water.
•  Most tsunami are caused by undersea earthquakes.
•  Although we can’t predict tsunami-causing events, there are systems to assess the risk and severity of tsunami that may occur after events have been detected.

The word 'tsunami' is Japanese, meaning 'harbour waves'. The Japanese know a lot about the destructive nature of these giant waves, having suffered from their effects for centuries. But the term 'harbour wave' is misleading, since tsunami don't just occur in harbours. Nor are they ‘tidal waves’—although the height of the tide may affect the strength of their impact, they are not controlled nor caused by tidal movements.

If we want a descriptive name for them, although it’s not very catchy, we could call them ‘displacement waves’, as they are caused when some sort of land movement causes a large amount of water to be displaced. Tsunami can be caused by undersea landslides, or the slumping of large amounts of rock or sediment into the sea. Volcanic eruptions, explosions and meteorite impacts can also cause tsunami. A meteorite 5–6  kilometres in diameter landing in the middle of the Atlantic Ocean would apparently create a tsunami  that would swamp the entire upper east coast of the USA. No need for immediate alarm though—Earth is likely to be struck by an asteroid of that size every 26 million years or so.

What is a subduction zone?

By far the most common cause of tsunami is undersea earthquakes, and usually it’s earthquakes associated with subduction zones. When an earthquake occurs, big chunks of Earth’s crust are displaced. If these massive chunks of Earth’s crust are under the ocean, the movement causes the water lying above it to also shift, shunting huge amounts of water away from the source of the earthquake in a series of huge waves.

A subduction zone occurs when two tectonic plates meet and one plate ‘slides’ beneath the other. This happens because Earth has two main types of crust—continental crust and oceanic crust. They are made of different minerals and oceanic crust is denser than continental crust. When a plate carrying oceanic crust collides with a plate carrying continental crust, the denser oceanic crust is forced below the continental crust. Around 90 per cent of all earthquakes worldwide occur along the subduction zones around the Pacific Ocean—the Pacific ‘Rim of Fire’. The movement of tectonic plates in this process can cause very large displacements in the ocean floor, which is why they so are so often accompanied by tsunami.

The energy within a tsunami

The earthquake or other disturbance that causes a tsunami can impart a great deal of energy into the wave. The energy (the capacity to do work) in any ocean wave is proportional the square of the wave height (the distance between the trough and the crest). A wave’s power (the rate at which work is done) is determined by the wave length—the distance between two crests—and the wave height. 

Most ocean swell waves have a wave length of around 30–40 kilometres. A high-energy tsunami in the deep ocean may have a height of less than a metre but a wave length of hundreds of kilometres—in effect, its energy is spread out across the ocean. The long wave length of tsunami means that they lose energy quite slowly, so they can travel vast distances and still wreak havoc when they hit a coastline. 

For example, an off-shore earthquake near Chile in 1960 sent waves speeding in all directions across the Pacific Ocean. The height of the waves was no more than a metre or so—which means they’re not easily noticeable to the naked eye. The waves travelled extremely fast and, just 22 hours later, a wave 6 metres high struck the coast of Japan on the other side of the ocean, killing around 200 people. This tsunami was felt in Australia too , with wave heights up to 84 centimetres recorded in Sydney Harbour. The tsunami continued to reverberate around the Pacific for days, causing damage whenever it struck land. 

So what caused the tsunami, which had a height of one metre out in the deep ocean, to be six metres high when it struck land?

Well, as water becomes shallower, the wave length and wave velocity both decrease, but the wave doesn’t lose any of its energy. To satisfy the relationship between wave length, wave height and energy, this means that the wave height must increase. So, as waves approach land from the deep ocean, their height increases. 

The impacts of tsunami

Many tsunami don't break as they hit land. They simply surge, flooding low-lying areas and rebounding off cliffs or hills, often causing as much or more damage as they recede back into the ocean. What’s more, remembering that tsunami are a series of waves, there’s not just one hit. Often there will be wave after wave of tsunami, resulting in a continued destructive sweep that occurs over a period of up to 24 hours, and sometimes even longer. Tsunami have been known to reach several kilometres inland, with the power to carry cars or ships along with them.

Along with the obvious risk to human lives, coastal inundation and flooding can occur, with significant damage to buildings and other infrastructure. There can be serious consequences if this infrastructure happens to be, say, a nuclear power plant. The Tōhoku earthquake that occurred off the coast of Japan in 2011 led to a tsunami that hit the eastern coast of the country where the Fukushima Daiichi nuclear power plant is located. The plant was badly damaged, causing a Level 7 meltdown. Radioactive material was spilled into the surrounding environment—a serious nuclear disaster. Some tsunami may not have a significant impact on coastal areas, but can still make their presence felt in the form of dangerous rips and currents offshore. Tsunami can circle the globe more than once, with their effects lasting for days.

THE 2004 INDIAN OCEAN TSUNAMI

The tsunami that struck coastal regions of the Indian Ocean on 26 December 2004 killed more than 289,000 people and left many more injured or without homes. The surge of sea water that caused the destruction was the result of the largest earthquake in the world for 40 years. The main earthquake was magnitude 9.1 and was followed by a series of aftershocks of between 5.7 and 7.3 in intensity. Less severe earthquakes are often measured in the region.

The earthquake was caused by the movement of the India plate and the Eurasia plate. The India plate is moving north at an average of 6 centimetres per year and is being forced under the continental Burma plate. On 26 December, the plates suddenly shifted 15 metres over a length of 1,200 kilometres. The amount of vertical displacement of the crust varied (some parts were uplifted, other parts subsided), but was generally around 4–5 metres. The epicentre of the earthquake was off the west coast of northern Sumatra, Indonesia. The shift in the plates on the ocean floor created a tsunami, which spread across the Indian Ocean and caused devastation in coastal settlements in Asia and Africa.

Unfortunately, at that time, there was no early warning system for tsunami in countries surrounding the Indian Ocean as there is in the Pacific. The earthquake was detected by many monitoring stations, but there were no tsunami detection buoys in place to pick up the signs of an impending/incoming tsunami. And while there was some information regarding tide heights being measured, this data was not available in real time for the type of analysis and assessment necessary to issue adequate warnings.

In response to the event, the UNESCO Intergovernmental Oceanographic Commission established the Indian Ocean Warning and Mitigation System. At first the Japan Meteorological Agency and the Pacific Tsunami Warning Centre provided information, and since 2011 three tsunami service providers have provided tsunami threat information to the 28 nations of the Indian Ocean region.

THE TŌHOKU EARTHQUAKE AND TSUNAMI

Off the east coast of Japan, the Pacific plate is subducting beneath the Eurasian plate. On 11 March, 2011, a magnitude 9.1 earthquake was triggered by the sudden rapid movement within this subduction zone. The quake shook the ground for 6 minutes. Its epicentre was 72 kilometres offshore from the eastern coast of Japan, and 30 kilometres underground. It took less than an hour for the first tsunami wave to hit. This earthquake was so powerful it shifted the island of Honshu to the east by around two and a half metres, dropped the coastline of Honshu by around half a metre and even affected the axis of Earth’s rotation.

The water surged as far as 10 kilometres inland in Sendai, and reached heights of 39 metres above sea level at Miyako city. Flooding covered an area of around 560 square kilometres. More than 15,000 people were killed.

We felt the effects of this tsunami in Australia, too, but with nowhere near the force that hit Japan. Unusually strong currents were reported in Sydney Harbour and Port Kembla, and some swimmers were swept into the lagoon at the coastal town of Merimbula in southern New South Wales. Around 18 hours after the earthquake, waves of around 30 centimetres high hit the coast of Antarctica.

Predicting and preparing for tsunami

There is a huge amount of variability in the actual events that can cause tsunami—earthquakes can have vastly different magnitudes and very different displacement regimes. The concentration of the quake’s energy will impact the way the seismic waves propagate through the surrounding rock, and the rock types themselves can also affect the way seismic waves travel. 

Generally, only earthquakes with a magnitude greater than 6.5 will generate tsunami, and the most destructive tsunami are generated from earthquakes that occur in relatively shallow regions of the crust. 

While forecasting future tsunami-generating events is basically not possible beyond statistical predictions based on records of past events, a lot of work has gone into figuring out how tsunami behave and what their impacts may be. 

Factors like the shape of the sea-bed, the water depth and the coastal landscape all affect the way tsunami travel and impact on coastal areas. Coastal harbours and headlands can cause the waves to bounce back into each other and change their direction—tsunami (and other waves) can 'bend' around islands, eventually engulfing the coast on what was supposedly the protected side. Other complicating factors include the effect of backwash from one wave on the waves that follow, and the exact nature of the disturbance that generated the tsunami in the first place. 

A tsunami can travel at the speed of a commercial jet—around 640–960 kilometres per hour. This is pretty fast, but it does give people some time to respond and prepare if adequate warnings promptly follow the tsunami-generating event. This obviously depends on how far away people are from the earthquake’s epicentre—in mainland Australia we’re likely to be far enough away from the action to have adequate time, but other nations situated closer to the Pacific Rim of Fire may have very little time to respond.

Along with all the seismic monitors that have been deployed on land are buoys positioned in the ocean that detect changes in pressure that result from the movement of a large amount of water. These are used to detect the presence of tsunami and track the direction and speed of their movement.

And it’s not just being able to predict how the impacts of a tsunami may pan out—‘peacetime’ preparedness is just as important. Having appropriate procedures in place to quickly assess the risk of a tsunami, issue effective and clear warnings and manage evacuation procedures are essential. Ensuring residents who live in high-risk areas for tsunami are educated and aware of both the risks and appropriate actions to take in the event of a tsunami is also important. 

The Australian Bureau of Meteorology has modelled almost two thousand tsunami to create a set of ‘canned’ scenarios that describe the likely impact of tsunami generated by earthquakes of various magnitudes and locations. This ‘library’ of possible events serves as a guide for emergency managers when it comes to preparing for tsunami events and issuing warnings.

We must also remember that even with the best possible information and preparedness strategies, nature can still be unpredictable and surprise us. Around 100 tsunami evacuation centres in Sendai were affected by the tsunami during the Tōhoku event in 2011, highlighting the importance of continuous risk-assessment. 

A thing to remember is that all warning systems and preparation procedures depend on accurate and timely detection of the event that causes the tsunami. If the tsunami is caused by something other than an earthquake, say, an underwater landslide, there will most likely be no warning (unless there is an appropriate array of tsunami detection buoys in the vicinity). 

The Joint Australian Tsunami Warning Centre

A number of Australian government agencies—the Bureau of Meteorology, Geoscience Australia and the Attorney General’s Department—all work together to support the Joint Australian Tsunami Warning Centre (JATWC). 

Geoscience Australia is responsible for overseeing a series of seismic monitors in the Indian, Pacific and Southern oceans that provide near-instantaneous information regarding earthquake events. An automated system reviews events to determine the likelihood that a tsunami will result. An expert seismologist then makes a final determination and passes on relevant information to the Bureau of Meteorology, within 15 minutes of the earthquake event. 

The Bureau of Meteorology manages an array of coastal sea level gauges and oceanic tsunami detection buoys and uses the information from these, along with the seismic information from Geoscience Australia, to select the appropriate pre-computed scenario, assess the ultimate tsunami risk and potential severity and then issues any appropriate warnings. The JATWC continues to monitor the event to see if it unfolds according to the prediction, and updates warnings and advice as necessary. 

The JATWC also participates in international efforts to provide warning of potential tsunami in the Indian Ocean, contributing information to the Indian Ocean Tsunami Warning and Mitigation System. The national authority of each country is then responsible for issuing tsunami warnings to their citizens.

While tsunami events are rare, they can be devastating. However, through a combination of rigorous science, consistent and reliable monitoring of our Earth and oceans, and appropriate preparation and warning procedures, we are working towards a better understanding of these potentially deadly events to protect our communities and keep people safe. 

How do you predict an earthquake?

Feeling the heat: geothermal energy, population and environment: a global challenge.

• environment

INTERVIEW: ‘Education has power to save lives,’ survivors say, ahead of first Tsunami Awareness Day

Facebook Twitter Print Email

Ahead of the inaugural World Tsunami Awareness Day on 5 November, two survivors of the most devastating tsunami in recent history – a Czech supermodel and a member of the Spanish family featured in the film The Impossible (2012) – have joined the United Nations’ commemoration of the Day.

“It’s like a concrete building, not water, falling on you,” Petra Nemcova, a 37-year-old fashion model and philanthropist, told the UN News Centre, describing the impact of the Indian Ocean Tsunami on 26 December 2004, which hit her and her partner in a bungalow on a Thai beach.

There was no warning, she said. In seconds, the bungalow completely crashed and there was glass everywhere and they were trying to hold on for dear life. She almost drowned many times, but after holding onto a palm tree for eight hours, she was found by a Thai man who risked his life to save the lives of strangers. Her partner was a strong swimmer but the power of nature was too strong for anyone.

Unfortunately, he was among the roughly 9,000 foreign tourists that perished in the disaster, which left more than 220,000 people dead.

In that moment, I didn’t have a choice. But now I have a choice to help children

“I’m happy to hear that finally tsunami has a dedicated international day to raise the awareness of the importance of early warning systems, education and preparedness,” she said, stressing that “the power of education is not just to transform lives but the power of education is to really save lives.”

She said that there is usually time to evacuate in the wake of earthquakes. The 2004 tsunami took two hours to strike Thailand. “In two hours, you can save your lives if there is an early warning system and enough education.”

“Time is of the essence here. There is no excuse for countries not to have an early warning system or education,” she said.

She defines herself as a supermodel, philanthropist and entrepreneur. Her tragic experience changed her perspective about life.

While holding on to a palm tree, she heard children screaming. She couldn’t swim and help them because debris was around her. After half an hour she couldn’t hear their voices anymore, which meant that they couldn’t hold on any longer.

“In that moment, I didn’t have a choice,” she said. “But now I have a choice to help children.”

In 2006, she founded Happy Hearts Fund (HHF), whose mission is to rebuild safe, resilient schools in areas impacted by natural disasters. “I’m happy to announce that we have now rebuilt 150 schools in 10 countries,” including Thailand, Indonesia, Chile, Peru, Mexico, and Haiti.

Ms. Nemcova said that tsunami awareness education should take place everywhere, not just in school, because everyone travels. She proposed “smart partnerships,” such as with airlines, which can introduce measures to warn passengers against disaster risks.

Tomas Alvarez-Belon, now 20 years old, was only eight, when he, his father Quique, mother Maria and brothers Simon, five, and Lucas 10, were staying at a resort hotel in the Khao Lak region of Thailand. All survived and reunited. The story of his family was portrayed in the film, The Impossible.

He was by a pool around 8 o’clock in the morning. “All of the sudden, the world started to shake, you don't understand what's happening. You suddenly see a black wall,” he told the UN News Centre. People imagine big waves they can recognize, but that was not the case. “A massive wall approaches so fast, and before you even understand what happened, you are being drowned or pulled into the water.”

When he finally resurfaced, “you don't see the world, you see people floating, people screaming, you see torn buildings. It’s hard to recognize reality.”

As for World Tsunami Awareness Day , he said “it is important that the world can not only mark an occasion to remember the victims of the disasters that have changed the course of history, and the course of many of our lives, but also to raise the awareness that we can prepare better and can avoid future deaths.”

“It's never easy to go back to the moment of a tsunami and what happened in the aftermath, but it is so important to get the message out,” he said, adding that he feels so fortunate to be able to share the story for a higher cause to fight for.

When he tells his traumatic experience, there are two key messages he underlines.

“First is the humanity of what we saw, how people helped each other anonymously – they did not have to be from the same country, from the same race, from the same religion. It was human helping human, and that is the core of my message,” he said.

It needs to be a movement that is born here in the UN and then spreads to Governments, and then from Governments to their people

“Second is that a lot of what happened on the day tsunami hit could have been avoided if the warning system had worked […],” he said, stressing that hundreds of thousands of lives could have been saved.

Evidently, tsunami changed how he approaches nature. When he goes to a beach, he thinks about what the tallest building is around there and where he could evacuate. “It's not a human instinct to think that way because when you are on a beach, you want to have fun,” he said, stressing the need for local authorities to make visitors aware of tsunami risk.

“People around the world look up to the UN as a voice of reason, impartiality and sanity,” said Mr. Belon, who is currently studying a B.S. in Science, Technology and International Affairs at Georgetown University. “It needs to be a movement that is born here in the UN and then spreads to Governments, and then from Governments to their people.”

“We want to see concrete actions and we hope that the UN is the place where those actions begin,” he said.

The tsunami experience has made him think deeply about what he wants to do with his life, how fortunate he is to be alive, how valuable each day is and how he needs to be dedicated to helping others. “At the core of it is the humanity that resides inside each of us,” he said.

• climate change

Tsunami Warning System: Preparing for the unpredictable

UNESCO is the UN Agency in charge of ocean science. With its Intergovernmental Oceanographic Commission joined by 150 Member States, and its expertise in the culture and education fields, UNESCO coordinates actions by governments, scientists, the private sector, civil society and other UN organizations. Together, we created the tsunami warning system. We map the ocean depths, identify species, work to ensure that ocean literacy is included in school curricula and protect ocean sites, which are home to critical biodiversity and incomparable beauty. In this story, we tell you more about UNESCO’s work on the tsunami early warning system, how it works and how it saves lives.

Tsunamis are rare events. But when nature’s fury is unleashed, their deadly effects are devastating. The initial impact may make the front page of news media, but the aftermath on communities, livelihoods and the environment will linger for many years after the natural disaster strikes.

In the last century, 58 of them have claimed more than 260,000 lives, surpassing any other natural hazard. More are expected in the future as the sea-level rises due to climate change.

Therefore, preparing for the unpredictable can mean the difference between surviving and not.

11 March, 14:00 UTC: the Earth shakes

An earthquake occurs in the Atlantic, 100 kilometres east of the Lesser Antilles – the long, delicate arc of small Caribbean islands fanning out between the Caribbean Sea and the open ocean. The volcanic archipelago, home to 3.2 million people, is perched on one of the tectonic plates that sit on the Earth’s crust.

Just as the plate slips along the Caribbean fault line, a massive burst of energy akin to a nuclear warhead explosion sets off a giant shockwave 25 kilometres beneath the planet’s surface.

Strong earthquakes are highly destructive in their own right. But they can also trigger other cataclysmic natural hazards.

As the seabed suddenly rises, it displaces colossal volumes of water, producing powerful waves that spread outward in all directions, just like the ripples from a stone thrown into a pond.

The smaller, ocean-facing Antilles are on the frontline of the looming wave. The larger islands – Cuba, Haiti, Jamaica and Puerto Rico  – as well as the communities in the Gulf of Mexico and coastal Venezuela, are also under threat. Nearly 160 million people are in imminent danger.

Tsunami Waves : digitally-scanned photos from the ITIC collection

11 March, 14:02 UTC: the earthquake is detected, tsunami sensors activate

The monitoring station in Martinique picks up the tremor and estimates it at 8.5 on the Richter scale. The large magnitude is cause for concern. Major earthquakes that occur beneath the sea lead to deadly tsunamis. Still, visual detection in the vast open ocean remains challenging because the powerful tsunami waves are low in height while they travel across deep water.   

That is why shore-based tide gauges and deep-ocean buoys continuously monitor the oceans to detect any threatening changes. These silent sentinels can spy and track any minuscule change in the temperature of the seafloor and its pressure.

An ocean buoy anchored in the depths of Barbuda – a flat coral island hugged by white-and-pink sand beaches and crystal-clear waters – senses the force of the hidden submarine wave and alerts the monitoring centre on the sister island of Antigua.

11 March, 14:05 UTC: the Tsunami Warning System raises the alarm

Antigua feeds the data on the force of the approaching wave into the Tsunami Warning System, which alerts all observatories in the region. Authorities in all neighbouring countries are immediately alerted: the rapid transmission of information to dedicated centres is vital to lessen the damage caused by tsunamis.

Disaster prediction and prevention Preventing large-scale disasters calls for a high degree of international and multilateral cooperation. After the 1960 Chilean tsunami, which left a trail of death and damage as far away as Japan, UNESCO’s Intergovernmental Oceanographic Commission (IOC-UNESCO) stepped in to set up the Pacific Ocean Tsunami Warning System, the first of its kind.

The 9.5 magnitude earthquake in Chile, the largest recorded in the 20th century, set off a tsunami that battered the South American coastline for over 4,000 kilometres with waves up to 25 metres high.

Fifteen hours later, the tsunami, which by then had travelled 10,000 kilometres, struck Hawaii, then Japan and the Philippines. The final death toll was over 2,000.

The scale of the disaster highlighted the need for a warning alert system in the Pacific, where most of the world’s deadliest tsunamis occur. Over the years, the alert system has evolved beyond issuing warnings. UNESCO’s role now includes prevention, preparing communities to respond to tsunami threats and fostering the latest tracking and detection technologies.

Other exposed regions, the Indian Ocean, the Caribbean, the Northeast Atlantic and the Mediterranean, have also adopted Early Tsunami Warning Systems based on the Pacific model.

11 March, 14:15 UTC: public alerts go out

The tidal wave is already in sight of the Lesser Antilles. There is little time left before it hits the coast. Tsunami waves in the deep ocean can travel thousands of kilometres, up to 800 kilometres per hour, the speed of a jet aircraft.

In Martinique, the local government alerts the municipalities and the media, which immediately publish alerts. Police sirens and loudspeakers give evacuation orders. Guided by their teachers, schoolchildren rush out of their classrooms, heading for higher ground. Office workers and tourists seek safety on the rooftops of high-rise buildings.

Empowering communities to react An early warning system can be effective only when the population is well aware of the tsunami phenomenon and knows what to do in case of an emergency.

This is vital when tsunamis are generated close to the coast and there may not be time for official evacuation orders.

As part of IOC-UNESCO coordination plans, communities are empowered to play an active role through self-evacuation if a strong earthquake is felt or a strong roaring sound – similar to a train or a jet aircraft – is heard. Highly visible and labelled evacuation routes help show the best access to nearby higher grounds or the higher floors of tsunami-proof buildings.

11 March, 14:16 UTC: the sea level drops

As the tsunami approaches the coast, the sea is drawn back due to the vacuum effect caused by the wave. The water along the shoreline of Anguilla, the most northerly of the Leeward Islands in the Lesser Antilles, is dragged back dramatically, exposing the shallow coral reef and stranding many marine creatures.

The expanding shoreline is nature’s warning that a tsunami is approaching. It is a sign that there are only seconds or, at best few minutes, before the full impact of the first wave.

When the sea disappears Survivors of the 2004 Indian Ocean tsunami said the water had receded for up to 2.5 kilometres along the coastlines of Indonesia and Thailand. Bystanders, many of them children, lingered on the exposed beach to observe the phenomenon and collect stranded fish.

The lack of tsunami awareness, combined with the absence of a coordinated alert system, contributed to the high death toll. There were an estimated 227,000 fatalities in 14 countries, with India, Indonesia, Sri Lanka and Thailand being the hardest-hit.

Still, some coastal communities in Indonesia were able to evacuate despite the lack of alarms, thanks to local traditions and folklore developed during previous tsunami disasters.   

The tragedy highlighted the importance of understanding the early signals of an approaching tsunami.

For example, the "disappearing sea" may not happen at all. Sometimes the sea suddenly swells without any warning signs, surprising people and giving them little time to flee.

Tsunamis can be detected using the human senses

Tsunami evacuation signs.

11 March, 14:20 UTC: the first wave hits

When the swell approaches the shore, the leading edge of the wave begins to slow down in shallow waters. As the tsunami loses its speed nearing the coast, the first wave suddenly swells as much as 20 metres in height. The massive wall of water rushes towards the coastline, demolishing everything in its way. The force of the wave is powerful enough to overturn boats, crumble palm trees and sweep away beach shacks.

Why is it called tsunami ? The flatter the coast, the stronger is the impact from the waves. This is the reason why the effects of the tsunamis are more devastating in ports, beaches and in the mouths of the rivers. It also explains the origin of the word. In Japanese, tsunami means bay or harbour wave.

11 March, 14:40 UTC: the second wave hits

Tsunamis always surge in multiple waves. The first wave may not be the largest, and often it is the second or later waves that are the biggest.

The second wave, towering at 30 metres, hits after as little as five minutes. The coastal areas are completely devastated and under water.

We heard a second wave, and another. There were no houses anymore.

A tsunami survivor

In 1950, Markus Kailhulu was a 12-year-old living in the village of Hutumuri in Indonesia, when a tsunami hit the Moluccas. The villagers had evacuated to higher ground and witnessed the destruction brought by the waves.

We went to see and it looked like a flood from up there. We heard a second wave, and another. There were no houses anymore, all gone,’ he says. ‘The waves swept it all. It hit the edge of the mountain, it went back while taking the houses. The church was the only building left.

11 March, 15:00 UTC: other waves hit

The first two waves were massive walls of water. The others now resemble a surging tide that inundates coastal areas, carrying debris from the destruction caused by previous waves.

Entire neighbourhoods have been washed away. Up on the hills, people stare at the devastation below with fear and incomprehension.

World Tsunami Awareness Day People experiencing a tsunami should be aware that the danger may not have passed and should await official confirmation that it is safe to return. Raising awareness and education among the coastal communities is essential to prepare citizens on how to respond to the risk of tsunamis and cope with their aftermath. The UN-supported World Tsunami Awareness Day is the brainchild of Japan, which due to its repeated experience with tsunamis, has built up over the years major expertise in early warnings and public awareness to reduce future impacts. The event, held every year on 5 November, calls on countries, international bodies and civil society to raise tsunami awareness and share innovative approaches to reduce the death toll and devastation. Posters, flyers, e-learning courses and guidelines as well as games teach children, who are among the most vulnerable groups, how to identify and cope with a tsunami.

World Tsunami Awareness Day

"The game is fun and worth a try." Tsunami Ready board game, World Tsunami Awareness Day 2021, Indian Ocean.

Playing the Tsunami Ready game

The Indian Ocean Tsunami Information Centre has developed a Tsunami Ready board game for children living in the coastal communities. "Playing the game, I’m able to learn a lot, such as what are the mitigation efforts that we can do at community, family as well as individual levels," says Sasa Tsairoo, a young game player who took part in the World Tsunami Awareness Day in 2021. "The game is fun and worth a try."

11 March, 19:43: rescue and recovery begins

Local authorities issue an "all clear" that it’s safe to return to the coastal areas. People rush out into the streets, stunned. In the midst of flooding and devastation, search and rescue teams are busy across the archipelago in a desperate attempt to find survivors. Essential utilities like water, telecommunications, gas lines and electricity are inoperable. The coastline is devastated with flooding, damaged buildings, debris, fires and hazardous spills. Many are missing. Many more have lost their homes and may have to stay in shelters or public buildings until the reconstruction begins.

Reality or fiction? This report is, in fact, the fictional scenario of a tsunami in the Caribbean, based on a drill exercise.

Caribe Wave is an annual tsunami preparedness exercise set up by the United Nations and overseen by IOC-UNESCO. The date and time of the simulation are not a random choice: it is the anniversary of the Japan earthquake and tsunami that killed nearly 16,000 people on 11 March 2011.

Under IOC-UNESCO’s oversight, the drills allow different countries and territories, emergency management agencies and communities at risk to test, validate and update their tsunami response plans. 

The exercise, which in 2019 involved up to 800,000 people to simulate a catastrophic scenario, focuses on the coordination among countries, improving response procedures and training the local population to become prepared.

It also plays a crucial role in fostering resilient communities. Tsunamis are a real threat in the Caribbean. At least 75 have hit the region over the past 500 years. Some countries facing the Gulf of Mexico are also exposed to the double threat of tsunamis along their Pacific coastlines.

Thanks to Caribe Wave, over 50 coastal communities are now considered Tsunami Ready. This means that these communities now have the tools to face not just tsunamis, but also other coastal hazards.

Tsunami Ready recognition As of 2021, six countries have piloted UNESCO’s Tsunami Ready Programme, while seven more are in progress. The programme aims to build resilient communities through awareness and preparedness strategies that will protect life, livelihoods and property from future tsunamis.

One of the achievements in becoming Tsunami Ready for us in Saint Kitts and Nevis was the ability to enhance our disaster preparedness. That was very vital and critical in also encompassing coastal hazards

"The ability to enhance our disaster preparedness" – World Tsunami Awareness Day 2021, Saint Kitts and Nevis

Preparing for future tsunamis

Millions of people live in coastal areas across the world where the rising sea level is increasing the risk of tsunamis.

In 2021, the United Nations set the goal of making all at-risk communities Tsunami Ready by 2030. IOC-UNESCO Tsunami Ready recognition has shown how different countries and communities can work together to reduce the risk of catastrophic coastal hazards that can cause death and destruction, hitting the livelihoods of vulnerable populations.

By improving warnings, enhancing preparedness and practicing response drills, these communities can prepare and become resilient, together.

"The Tsunami Ready programme reduces the risk for our communities." World Tsunami Awareness Day 2021

Related items

• Warning systems

Based on Zip Code Change

• Shop the Red Cross Store

Tsunami Preparedness

• Share via Email
• Share on Facebook
• Share on Twitter
• Share on LinkedIn

Need Help Now?

If you are in immediate need of help, please  contact your local Red Cross » or  find an open shelter » .

A tsunami is a series of ocean waves caused by earthquakes, landslides, or volcanic eruptions. These waves can kill and injure people and destroy entire communities. Tsunamis strike as fast moving walls of water that flood, drain, and re flood the land for hours. Tsunamis can flood more than a mile inland. But we can take action to prepare. Prepare now to protect yourself and your loved ones.

What Should You Do Before a Tsunami

Know your risk  .

• Tsunamis can strike any U.S. coast, but the risk is greatest for communities with Pacific and Caribbean coastlines. Coastal areas such as beaches, bays, lagoons, harbors and river mouths and areas along rivers and streams that lead to the ocean are the most vulnerable.
• If you live on or near a coast, find out if you are in a tsunami hazard zone.

Make Plans to Stay Safe

• Learn about your community’s tsunami evacuation plan. Some communities have maps with evacuation zones and routes. Know and practice these routes in the places where you spend time.
• If your community does not have a tsunami evacuation plan, identify a safe place at least 100 feet (30 meters) above sea level or at least 1 mile (1.6 km) inland.
• Be ready to move quickly to higher ground or inland. Don’t wait for an official alert.
• If you are near the coast, a tsunami could follow an earthquake. As soon as the shaking stops, move quickly to higher ground or inland away from the coast. Don’t wait for an official alert.

Understand Tsunami Alerts and Natural Signs of a Tsunami  

• There are two ways that you may be warned: an official tsunami alert or a natural sign of a tsunami. Both are equally important. You may not get both.
• A natural sign of a tsunami may be your first, best, or only warning that a tsunami is on its way. Natural signs include an earthquake, a loud roar from the ocean, or unusual ocean behavior, such as a sudden rise or wall of water or a sudden retreat of the water, showing the ocean floor. If you experience any of these signs, a tsunami could be coming. Immediately move to higher ground or inland away from the coast. Don’t wait for an official alert.
• Tsunami alerts are shared on local radio, television, weather radios, and other emergency alert systems. Understand the different alerts and what to do when you receive them.

Download the Tsunami Safety Checklist

Checklist Available in English and Spanish

• Tsunami Safety Checklist - English
• Tsunami Safety Checklist - Spanish

Get Preparation Tips for the Whole Family

What Should You Do During a Tsunami

Move to high ground or inland.

If your community is under a Tsunami Warning or you see natural signs of a tsunami:  

• DANGER-TAKE IMMEDIATE ACTION! MOVE TO HIGH GROUND OR INLAND (AWAY FROM THE WATER).
• If you are near the coast and experience shaking from an earthquake: DROP , COVER , and HOLD ON to protect yourself. As soon as the shaking stops, MOVE TO HIGH GROUND OR INLAND (AWAY FROM THE WATER).
• Once you have evacuated, stay there until officials say it is safe to return home or direct you to evacuate further inland.

What Should You Do After a Tsunami

Stay safe  .

• Understand the dangers you may face after a tsunami. Many injuries happen during cleanup.
• If you have evacuated, listen to local officials to learn if it is safe to return home. If there is a lot of damage, it may be days before it is safe to return to your community.
• Avoid roads that were flooded, they may be damaged and could collapse.
• Do not touch floodwaters. They may contain sewage, bacteria, and chemicals that can make you sick.
• Avoid damaged or fallen power lines. Assume all wires are live and dangerous.
• When officials allow, inspect the outside of your home for damage before reentering.
• If your home is damaged, it may be safer to wait for a professional.
• Be aware of carbon monoxide poisoning. Do not use gasoline, propane, natural gas or charcoal-burning devices inside a home, basement, garage, tent, or camper — or even outside near an open window. Carbon monoxide can’t be seen or smelled, but it can kill you fast. If you start to feel sick, dizzy or weak, get to fresh air right away — do not delay.
• Avoid using candles because of the fire risk. Use battery- powered lights and flashlights instead.

Stay Healthy

• Monitor your local health department for information about drinking water safety. Tsunamis can contaminate water supplies.
• When in doubt, throw it out. Throw away food that got wet or warm.
• Clean and disinfect everything that got wet. Mud left from floodwaters can contain sewage, bacteria, and chemicals. Mold can become a problem if a building is flooded and not completely dried out within 24-48 hours. Mold exposure can lead to asthma attacks, eye and skin irritation, and allergic reactions.

Clean Up Safely

• Follow all specific recommendations from your local public health officials. Use the right safety gear including gloves, goggles, rubber boots, and N95 masks. Know how to safely operate any needed equipment.
• Pace yourself. Cleaning up is a big job. Rest when you need to. Work with other people and get help lifting heavy objects. Decide which cleanup tasks are most important and focus on those first.
• Avoid heat-related illness. If you are without air conditioning in hot weather, be aware of risk for heat stroke, heat exhaustion, heat cramps, and fainting.

Take Care of Yourself

•  It’s normal to have a lot of bad feelings, stress, or anxiety after a disaster or other emergency.
• Eat healthy food and get enough sleep to help you deal with stress.
• You can contact the Disaster Distress Helpline for free if you need to talk to someone. Call or text 1-800-985-5990

Explore Related Safety Topics

Free App to Help Your Family Stay Safe

Find our Emergency App in the  Apple Store » or  Google Play »

Aplicación de Emergencias - ahora disponible en  español » también!

Help people affected by disasters big and small.

Tsunami’s Reasons and Effects Essay

Main causes of tsunami, ways to recognize the approach of a tsunami in advance, ways to reduce the risks of tsunami impacts, additional ways to predict tsunami, reference list.

For many inhabitants of the Earth, a tsunami threat looks like an abstract and very exotic danger. However, the vagaries of nature in recent years are such that it is quite difficult to feel completely protected from such a danger. Moreover, even in a small lake, under a certain confluence of circumstances, a large wave can arise. If it is about the cities located on the seashore or beside the ocean, the problem is urgent enough.

The knowledge of how to survive during a tsunami can be useful at the most unexpected moment and in almost any part of the globe. Therefore, it is essential to know ​​how to anticipate the place and time of the occurrence of a tsunami and to determine which factors are the main in assessing the potential wave’s power and the speed at which it approaches the land.

The central and most frequent cause of tsunami occurrence is underwater earthquakes. Powerful jerks create a directional movement of huge masses of water that roll to the shore with waves more than 10 meters high and bring casualties and destruction. It is not surprising that the greatest risk of occurrence of this natural disaster exists in coastal areas with increased seismic activity. Thus, everyone knows the example of the tsunami in Japan in 2011, which led to an incredible number of human casualties and triggered an accident at the Fukushima-1 nuclear power plant (Ikehara et al. 2014).

Quite often, there is a tsunami threat in the Philippines, Indonesia, and other island states of the Pacific. The consequences of tsunamis can be very serious, and this danger should be discussed in detail since many people are exposed to it.

The first reason to take care of a tsunami threat is the announcement of increased seismic activity in the coastal area. Earthquakes are natural signals notifying about a possible runup of a tsunami. In case seismologists manage to predict earth tremors in advance, the residents of settlements on the coast should ensure their safety in order not to expose their lives to danger. According to Melgar and Bock (2015), such warnings are relevant even if the earthquake’s strength in the city is low because the epicenter can be in the sea. That is why the threat is very dangerous in coastal areas where people, as a rule, are in no way protected from such a natural disaster.

During the moments of increased tsunami threat, the authorities’ reports on radio and television should be carefully monitored. In most cases, the danger becomes known in a few hours, which gives residents the opportunity to timely react to it. As tsunami witnesses note, animals are especially sensitive to the approach of a giant wave. Long before the onset of danger, they are worried. Many wild animals and birds tend to leave the area in advance.

It is also possible to predict the approach of a tsunami in fifteen-twenty minutes judging by the changes of the coastline. At this moment, the water quickly recedes, the sound of the surf subsides, the normal regime of tides breaks. In some cases, unusual and untimely tides lasting from several minutes to half an hour can be observed. As Leonard and Bednarski (2014) note, the tsunami of 2012 in Haida Gwaii was accompanied by a drift of unusual objects: fragments of ice or, for example, coastal debris that is raised from the bottom by the movement of water. The runup of the wave is always accompanied by thundering sounds since the mass of water is very large, and at high speed, its movement creates a very perceptible noise.

Modern technologies make it possible to predict not only the power of an upcoming tsunami but also an approximate time in which it will happen. The fact is that experts from the Japanese National Research Institute of Geophysics and Natural Disaster Prevention have developed a high-tech system that predicts these natural disasters. This unique project, as Lin et al. (2014) note, enables residents of the coastal areas to escape from a tsunami within twenty minutes after the alarm. This time will be enough to completely evacuate the area that is endangered and to save all the residents. There have not been severe disasters in Japan that could be similar to that in 2011, but if one happens, people are likely to be ready.

This system has already been launched and includes dozens of different detectors installed at one hundred and fifty points on the seabed along the Pacific coast of Japan from Hokkaido to Tokyo. Information from the sensors comes through the cable directly to the Japanese meteorological office. The development and construction of the system cost the Japanese budget several hundred million dollars. Nevertheless, today, scientists and rescuers will be able to learn about the earthquakes that took place under the water about twenty minutes earlier.

According to Riquelme et al. (2015, p. 6487), the primary idea of any work related to the ways of identification tsunamis is “to provide a tool for emergency response, trading off accuracy for speed”. The creation of a new system has become a new step in the development of science. It is quite easy to imagine how many lives can be saved by possessing the information that can be acquired with the help of those useful data that come from sensors located on the seabed.

In the middle of the twentieth century, after the catastrophic earthquake in Hawaii, the Pacific Tsunami Warning Service was established in the Pacific Ocean (Yeh & Mason 2014). Seismic stations record the time and place of the earthquake; if its epicenter lies under water, it is possible to expect a tsunami. In this case, all stations monitoring sea level are notified of the need to monitor the approach of big waves.

In order to calculate an approaching time, there are special maps of the duration of the tsunami run from various points to the Hawaiian Islands. The notification about the expected time of the approach of waves is transmitted via the international Pacific communication system. The headquarters of the Tsunami Warning Service (subordinate to the National Ocean Service of the National Oceanic and Atmospheric Administration) is in Honolulu.

Thus, it is significant to find out ​​how to anticipate the place and time of the occurrence of a tsunami. Those factors that signal an imminent threat are always important to consider. Appropriate equipment was invented after the disastrous effects of the tsunami in Japan. Earthquakes, as a rule, are the most common reasons for the emergence of large waves.

Ikehara, K, Irino, T, Usami, K, Jenkins, R, Omura, A & Ashi, J 2014, ‘Possible submarine tsunami deposits on the outer shelf of Sendai Bay, Japan resulting from the 2011 earthquake and tsunami off the Pacific coast of Tohoku’, Marine Geology , vol. 358, no. 1, pp. 120-127.

Leonard, LJ & Bednarski, JM 2014, ‘ Field survey following the 28 October 2012 Haida Gwaii tsunami ’, Pure and Applied Geophysics , vol. 171, no. 12, pp. 3467-3482.

Lin, JH, Cheng, CY, Yu, JL, Chen, YY & Chen, GY 2014, ‘Quick estimation of tsunami induced runup on coastal area’, Coastal Engineering Proceedings , vol. 1, no. 34, pp. 8-22.

Melgar, D & Bock, Y 2015, ‘Kinematic earthquake source inversion and tsunami runup prediction with regional geophysical data’, Journal of Geophysical Research: Solid Earth , vol. 120, no. 5, pp. 3324-3349.

Riquelme, S, Fuentes, M, Hayes, GP & Campos, J 2015, ‘A rapid estimation of near-field tsunami runup’, Journal of Geophysical Research: Solid Earth , vol. 120, no. 9, pp. 6487-6500.

Yeh, H & Mason, HB 2014, ‘Sediment response to tsunami loading: mechanisms and estimates’, Géotechnique , vol. 64, no. 2, pp. 131-143.

• Chicago (A-D)
• Chicago (N-B)

IvyPanda. (2020, October 28). Tsunami's Reasons and Effects. https://ivypanda.com/essays/tsunamis-reasons-and-effects/

"Tsunami's Reasons and Effects." IvyPanda , 28 Oct. 2020, ivypanda.com/essays/tsunamis-reasons-and-effects/.

IvyPanda . (2020) 'Tsunami's Reasons and Effects'. 28 October.

IvyPanda . 2020. "Tsunami's Reasons and Effects." October 28, 2020. https://ivypanda.com/essays/tsunamis-reasons-and-effects/.

1. IvyPanda . "Tsunami's Reasons and Effects." October 28, 2020. https://ivypanda.com/essays/tsunamis-reasons-and-effects/.

Bibliography

IvyPanda . "Tsunami's Reasons and Effects." October 28, 2020. https://ivypanda.com/essays/tsunamis-reasons-and-effects/.

• Tsunami: Definition and Causes
• Physical Aspect of Tsunami
• Natural Disasters: Earthquakes, Volcanoes, and Tsunamis
• Tsunami Handling at a Nuclear Power Plant
• Tsunami Warning Management System
• 2011 Tsunami in Tohoku and Its Effects on Japan
• Tsunamis and Their Harmful Effects on Countries
• Natural Hazard: Tsunami Caused by Earthquakes
• Tsunami Geological Origin
• Tsunami Disasters in Okushiri Island
• The Chernobyl Disaster: Time, Distance and Shielding
• Seton Hall Fire and Southern Adventist University Fire
• How to Prepare for a Hurricane?
• Wildland Fire Entrapment Investigation
• Flood Disaster Recovery Plan and Stakeholders

Tsunami Warning and Preparedness: An Assessment of the U.S. Tsunami Program and the Nation's Preparedness Efforts (2011)

Chapter: 1 introduction, chapter one introduction, the tsunami threat in the united states.

The 2004 Indian Ocean tsunami resulted in catastrophic losses of life and property and demonstrated how destructive tsunamis can be. More than 200,000 people died, with most occurring in Indonesia, which was near the tsunami source, but deaths were also reported in countries as far away as Somalia. Recently, the Samoan (September 2009) and Chilean (February 2010) tsunamis reminded the world of how quickly a tsunami can move onshore and destroy lives. In comparison to extreme weather—such as floods, hurricanes, or tornadoes—tsunamis have caused comparatively few fatalities in the United States over the past 200 years. Modern records kept since 1800 tally less than 800 lives lost due to tsunamis in the United States and territories. 1 In 1960, a magnitude 9.5 Chilean earthquake generated tsunami waves that killed 61 people and caused $24 million in property damage in Hilo, Hawaii (Eaton et al., 1961). The 1964 Good Friday earthquake in Alaska generated a tsunami that devastated local Alaskan communities and inundated distant communities as far south as Crescent City, California.

Earlier tsunamis—yet to be repeated in modern times—include tsunami waves of North American origin in the year 1700 that caused flooding and damage as far away as Japan. Paleo-records indicate that the Cascadia subduction zone off the Washington, Oregon, and northern California coasts has repeatedly generated potentially catastrophic tsunamis (Atwater et al., 2005). Because of the relative infrequency of catastrophic tsunamis in recent U.S. history, mobilizing the required resources to maintain the nation’s warning and preparedness capabilities is challenging.

Tsunamis are caused by a variety of geological processes, such as earthquakes, subaerial and submarine landslides, volcanic eruptions, or very rarely from meteorite impacts ( Box 1.1 ). However, it takes a large event (e.g., typically an earthquake of magnitude greater than 7.0) to generate a damaging tsunami. Therefore, determining the likelihood of future tsunamis for U.S. coastal communities requires an understanding of the likelihood of reoccurrence of such geological processes, the likely magnitude of such events, and the location of the sources (see Chapter 3 for additional details). Because most tsunamis result from earthquakes, the tsunami hazard is high along U.S. shores that adjoin boundaries between tectonic plates, particularly along the subduction zones of Alaska, the Pacific Northwest, the Caribbean, and the Marianas ( Figure 1.1 ). However, U.S. shores are also exposed to tsunamis generated far from them. For example, Hawaii has been struck by tsunamis that have been generated by earthquakes off the coasts of South America, Russia, and Alaska (Cox and Mink, 1963). Submarine landslides,

probably triggered by earthquakes, account for much of the known tsunami hazard along the U.S. Atlantic and Gulf coasts, and in southern California (Dunbar and Weaver, 2008). Seismically active faults and the potential for landslides in the Caribbean pose a significant tsunami risk for that region (Dunbar and Weaver, 2008).

Tsunami hazard zones of U.S. coastal communities contain thousands of residents, employees, and tourists, and represent significant economic components of these coastal communities (Wood, 2007; Wood et al., 2007; Wood and Soulard, 2008). The economic and social risks from tsunamis grow with increasing population density along the coasts. To reduce societal risks posed by tsunamis, the nation needs a clear understanding of the nature of the tsunami hazard (e.g., source, inundation area, speed of onset) and the societal characteristics of coastal communities (e.g., the number of people, buildings, infrastructure, and economic activities)

FIGURE 1.1 Global map of active volcanoes and plate tectonics illustrating the “Ring of Fire” and depicting subduction zones; both areas associated with frequent seismic activity. SOURCE: http://vulcan.wr.usgs.gov/Imgs/Gif/PlateTectonics/Maps/map_plate_tectonics_world_bw.gif; USGS .

that make them vulnerable to future tsunamis. With a clear understanding of the tsunami hazards and social vulnerability that comprise tsunami risk, officials and the general public can then prepare for future events and hopefully reduce this risk. 2

When assessing tsunami hazard and developing risk reduction measures, it is important to consider the distance between a coastal community and potential tsunami sources as well as the probability of occurrence. Near-field tsunamis (see Box 1.1 ) pose a greater threat to human life than far-field tsunamis because of the short time between generation and flooding; because the extent of flooding is likely greater; and because the flooded area may be reeling from an earthquake (National Science and Technology Council, 2005). Near-field tsunamis account for most U.S. tsunami deaths outside of Hawaii, but even Hawaii has suffered losses from near-field tsunamis. Because it takes a very large earthquake to impact the far-field, more triggering events have the potential to impact communities that are within an hour or less from the source. For example, an earthquake generated within the Cascadia fault zone along the northern California, Oregon, and Washington coasts will allow only minutes for evacuation of

the coastal communities after the earthquake is felt. In addition, tsunami observations demonstrate an increase in wave height with proximity to the source, resulting in extensive coastal flooding by a near-field tsunami. Consequences of a near-field tsunami are far greater for any given location.

Far-field tsunamis afford hours of advance notice for evacuation and are likely to have smaller wave heights than those in the tsunami’s near field. However, the farther a coastal community from the earthquake source the less likely it is to have felt the earthquake and the more dependent it is on an instrumental detection system to provide warnings. Timely and accurate warnings are required to implement orderly evacuations and to avoid frequent unnecessary evacuations, which can be costly. The National Science and Technology Council (NSTC) report (2005) concludes that “the challenge is to design a tsunami hazard mitigation program to protect life and property from two very different types of tsunami events.”

GOALS AND SCOPE OF THIS REPORT

The 2004 Indian Ocean tsunami, spurred two congressional acts intended to reduce losses of life and property from future tsunamis. The Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Tsunami Relief, 2005 (P.L. 109-13), included $24 million to improve tsunami warnings by expanding tsunami detection and earthquake monitoring capabilities. This Act was followed in 2006 by the Tsunami Warning and Education Act (P.L. 109-424), which directs the National Oceanic and Atmospheric Administration (NOAA) to strengthen the nation’s tsunami warning system (TWS), work with federal and state partners toward the mitigation of tsunami hazards, establish and maintain a tsunami research program, and assist with efforts to provide tsunami warnings and tsunami education overseas.

Section 4(j) of the Tsunami Warning and Education Act calls upon the National Academy of Sciences (NAS) “to review the tsunami detection, forecast, and warning program established under this Act to assess further modernization and coverage needs, as well as long-term operational reliability issues.” In response, NOAA asked the NAS to assess options to improve all aspects of the tsunami program. This request is reflected in the first part of the committee’s charge (see Appendix B ) and accordingly focuses on efforts on tsunami detection, forecasting, and warning dissemination.

The NAS, in accepting this charge and in consultation with NOAA, broadened the review’s scope to include an assessment of progress toward additional preparedness efforts to reduce loss of life and property from tsunamis in the United States as part of the National Tsunami Hazard Mitigation Program (NTHMP). The main rationale for this broadened scope was to address Section 5(a) in P.L. 109-424, which called for “a community-based tsunami hazard mitigation program to improve tsunami preparedness of at-risk areas in the United States and its territories.” Such a tsunami hazard mitigation program requires partnership among federal, state, tribal, and local governments. Its strategies include identifying and defining tsunami hazards, making inventories of the people and property in tsunami hazard zones, and providing the public with knowledge and infrastructure for evacuation, particularly for near-field

tsunamis that come ashore in a few minutes. The broadened scope aims at encompassing the range of national tsunami warning and preparedness efforts.

The Range of Options Available for Tsunami Hazard Mitigation

As the scope of the study was broadened to include aspects of tsunami hazard mitigation, the committee recognized the need to define the term “mitigation” and set some boundaries for the study, because the full suite of mitigation options exceeds the purview and capacity of this particular study. The definition of hazard mitigation and the actions it includes differ among various hazard communities. Some members of the academic community consider the full range of hazard mitigation options to include three classes of actions (White and Haas, 1975): (1) modifying the natural causes of hazards, (2) modifying society’s vulnerability (e.g., levees, wind- and seismic-resistant houses), and (3) redistributing the losses that occur (e.g., insurance, emergency response). In contrast, natural hazard practitioners consider the range of human adjustment to natural hazards to fall into two major classes of actions: (1) mitigation of potential losses through interventions in the constructed world in ways that lessen potential losses from nature’s extremes (e.g., land-use management, control and protection works, building codes), and (2) preparedness for, response to, and recovery from specific events and their associated losses (Mileti, 1999).

Focus on Warning and Preparedness

Although land-use planning and adjusting building codes is important in mitigating the impacts of tsunamis, the charge to the committee is focused primarily on the detection, forecast, and warning for near- and far-field tsunamis and issues directly related to the effective implementation of those warnings. To be responsive to its charge, the report focuses on the second class of mitigation actions, which generally includes pre-event planning to develop preparedness plans, appropriate organizational arrangements, training and exercises for issuing event-specific public warnings, an adequate emergency response, and plans for recovery and reconstruction. These types of adjustment are based on the notion that the adequacy of pre-event planning determines the effectiveness of event-specific response. This view also places insurance in the preparedness class.

THE NATION’S TSUNAMI WARNING AND PREPAREDNESS EFFORTS

Only very recently has there been a national interest in tsunami warning and preparedness. Before 2004, most efforts were spearheaded by local, state, or regional initiative operating on very limited budgets. Integrating these existing individual efforts into a national tsunami program has led to a very different type of program than that of a national tsunami warning program designed from the outset. The history of tsunami warning and preparedness efforts can be traced back to two of the six destructive tsunamis that caused causalities on U.S. soil.

These efforts were originally part of the National Geodetic Survey, which developed the two tsunami warning centers (TWCs) in Hawaii and Alaska after the 1946 Aleutian tsunami (Unimak Island, AK) and the 1964 Alaskan tsunami (Prince William Sound, AK) ( Figure 1.2 ). These centers eventually became part of NOAA’s National Weather Service (NWS), but each is located in different NWS regions and is managed independently.

Concern about tsunamis in Washington, Oregon, and California increased in the late 1980s and early 1990s when several new scientific studies revealed their near-field tsunami threat from the Cascadia subduction zone (Atwater, 1987; Heaton and Hartzell, 1987). California was reminded of its potential tsunami threat by an earthquake near Cape Mendocino in 1992, which generated a small tsunami that arrived in Eureka only minutes after the earthquake occurred. These and other developments prompted a more urgent call to produce comprehensive assessments of tsunami risk and preparedness at the state and federal level.

Congress responded to this call in a 1995 Senate Appropriations Committee request to NOAA to develop a plan for reducing tsunami risk to coastal communities. NOAA suggested the formation of a national committee to address tsunami threat, leading to the establishment of the NTHMP that same year. The NTHMP is tasked with coordinating the various federal, state, territorial, and commonwealth tsunami efforts. NOAA’s Tsunami Program was established in 2005 to incorporate all the current tsunami efforts at NOAA (see below). To respond to the committee’s charge (see Appendix B ) and assess progress made toward improved tsunami warning and preparedness, the committee begins its evaluation with an inventory of the elements of the NTHMP and NOAA’s Tsunami Program.

National Tsunami Hazard Mitigation Program

The NTHMP has a Coordinating Committee (steering committee) that works to collaborate on the tsunami mitigation efforts of the NTHMP and three subcommittees: a Mapping and Modeling Subcommittee, a Warning Coordination Subcommittee, and a Mitigation and Education Subcommittee. 3 In addition to coordinating individual efforts, the NTHMP provides guidance to NOAA’s TWSs. Federal partners include NOAA, the U.S. Geological Survey (USGS), and the Federal Emergency Management Agency (FEMA). State partners originally included Hawaii, Alaska, Washington, Oregon, and California, and now include all 29 U.S. coastal states and territories.

The USGS contributes to the seismic network that the TWCs use through operating and maintaining their respective seismic networks and to the tsunami research and risk assessments and conducts an independent seismic analysis of potential tsunamigenic earthquakes at its National Earthquake Information Center (NEIC). The USGS and NOAA both support the Global Seismographic Network (GSN), which provides high-quality seismic data to assist earthquake detection (including tsunamigenic earthquakes). Both agencies also support earthquake and seismic studies to improve tsunami warning efforts and tsunami disaster response and hazards assessments. FEMA is responsible for hazard mitigation and emergency response; as

FIGURE 1.2 Timelines for U.S. tsunami warning centers, programs, tsunami budget, deaths from tsunamis in the United States and its territories, and earthquakes of magnitude 8.0 or larger worldwide since the year 1900. Sources of data for this figure include: NOAA (federal spending); http://www.ngdc.noaa.gov/hazard/tsu_db.shtml (tsunami fatalities); http://earthquake.usgs.gov/earthquakes/eqarchives/ (great earthquake history). SOURCE: Committee member.

part of its mitigation efforts it has issued Guidelines for Design of Structures for Vertical Evacuation from Tsunamis (Federal Emergency Management Agency, 2008). FEMA becomes the lead federal agency in managing the emergency response once a tsunami has caused damage to U.S. coastlines.

The National Science Foundation (NSF) used to be a partner of the NTHMP, but as its involvement decreased the decision was made in 2009 to remove it from the NTHMP. Its primary function is to provide research funding and to partner with other federal agencies in research and development. NSF provides funding for the GSN. NSF has also been actively involved with investments regarding tsunami research infrastructure, such as the Network for Earthquake and Engineering Simulation (NEES), Earthquake Engineering and Research Centers (EERCs), and the Southern California Earthquake Center (SCEC) (Bement, 2005). Because it is not part of the NTHMP and its funding decisions are primarily driven by the demand in the research community, this report does not include an explicit discussion of NSF’s role but rather discusses the role of the broader research community in the nation’s tsunami efforts.

NOAA has been carrying most of the responsibility and obtains most of the funding to provide tsunami warnings, maintain observing networks (including seismic networks not funded by the USGS in Alaska and Hawaii), manage and archive data, and conduct research (further discussed in the next section).

The coastal states, U.S. territories, and commonwealths contribute their own initiatives and resources to the nation’s preparedness and education efforts; these vary in extent and approach from state to state. In particular, states are responsible for providing communities with inundation maps that allow municipalities to produce evacuation maps and guidance, and to educate the public about the hazard and appropriate responses. Local officials in turn are responsible for transmitting tsunami alerts throughout their respective jurisdictions, issuing evacuation orders, managing evacuations, and declaring all-clears.

NOAA’s Tsunami Program

In 2006, the Tsunami Warning and Education Act (P.L. 109-424) charged NOAA with addressing the nation’s priorities in tsunami detection, warning, and mitigation. NOAA’s Tsunami Program assumed the responsibilities to plan and execute NOAA’s tsunami efforts, primarily the program’s budget, strategic plan, and the coordination of activities among its NOAA organizational components and external partners, including the NTHMP. NOAA’s Tsunami Program advocates an end-to-end TWS, which includes detection, warnings and forecasts, message dissemination, outreach and education, and research.

NOAA’s Tsunami Program is supported by five line offices ( Table 1.1 ): NWS; the Office of Marine and Aviation Offices (OMAO); the National Ocean Service (NOS); Oceanic and Atmospheric Research (OAR); and the National Environmental Satellite, Data, and Information Service (NESDIS). The NWS, as the administrator for NOAA’s Tsunami Program, is primarily responsible for helping community leaders and emergency managers in strengthening their local tsunami

TABLE 1.1 Tsunami Program Matrix

warning and preparedness programs through its TsunamiReady program as well as operating the TWCs.

The Pacific Region’s Pacific Tsunami Warning Center (PTWC) and the Alaska Region’s West Coast/Alaska Tsunami Warning Center (WC/ATWC) are administered within the NWS, although the two TWCs report to their respective regional NWS offices. The two TWCs have distinct areas of responsibility as described in Chapter 5 . The NWS also houses the National Data Buoy Center (NDBC), which operates and maintains the Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys. These buoys monitor and alert the TWCs of sea level changes associated with a tsunami. OMAO collaborates by providing detection system maintenance support and conducting coastal surveys. NOS provides state and local coastal emergency managers with hazard-related information such as training and assessment tools, and also operates coastal tide stations and sea level gauges that monitor changes in sea level. OAR comprises a research network involving internal research laboratories, grant programs, and collaborative efforts between NOAA and academic institutions. Pacific Marine Environmentla Laboratory (PMEL), within OAR, focuses on designing optimal tsunami monitoring networks, improving forecast modeling, and improving impact assessment on coastal communities. NESDIS provides access to global environmental data; such as climate, geophysical, and oceanographic data. The National Geophysical Data Center (NGDC), housed within NESDIS, manages a database for historic tsunami events, maps, and DART and tide gauge records. Some negative consequences arising from this distribution of tsunami detection, forecast, warning, and planning functions across different parts of NOAA and across different NTHMP partners is discussed in greater detail in Chapters 3 and 5 .

ASSESSING THE NATION’S EFFORTS

Because tsunami warning and preparedness efforts are distributed across federal and state agencies and were historically conducted without a federal coordination mechanism, the committee faced a number of challenges in assessing progress in the nation’s ability to warn and prepare for the threat of tsunamis. The first challenge results from the need to assess many individual activities. Secondly, it is difficult to extrapolate from these individual activities to assess whether all the distributed efforts can function coherently during a tsunami to warn and evacuate people in a timely fashion. To help address these challenges, the committee began its analysis by sketching the required functions and elements of an idealized integrated warning and preparedness effort based on available research findings in the hazards and high-reliability organizations (HRO) literature (see section below). The committee then sought to compare its vision of an idealized system with the evolving status quo.

An ideal integrated TWS comprises multiple technologies, systems, individuals, and organizations. A comprehensive view of the elements therefore includes technical, organizational, social, and human components. The ideal system incorporates risk assessment, public education, tsunami detection, warning management, and public response ( Figure 1.3 ).

Protecting and warning the public begins with an understanding of the tsunami risk envi-

FIGURE 1.3 Components of an integrated warning system: Risk assessment includes all assessments required to effectively plan evacuations (including tsunami source determination, inundation modeling, and evacuation mapping) and prepare the communities to evacuate in the event a warning is issued or received. Risk assessments identify needs for public education. Public education aims to ensure maximum preparedness and a public that knows what to do when it receives a warning or feels the ground shaking in the case of near-field tsunamis. Threat detection comprises the continuous monitoring of the natural and technological environments that could create an emergency; it informs the warning management and public response component using threshold criteria and communication technology. Warning management interfaces the threat detection component with the public response component and is responsible for tsunami alerts, warnings, and evacuations; in consultation with the threat detection component it will alert and warn the public. Public response is the ultimate outcome of the integrated warning system, and it integrates public education, threat detection, natural cues from tsunami triggers, and warning management. SOURCE: Committee member; design by Jennifer Matthews, University of California, San Diego.

ronment. This must be done before a tsunami is generated in order to design the threat detection system, the education and awareness campaigns, and the evacuation and response plans. To understand the risk environment, both hazards (the physical characteristics of tsunamis and the inundation area) and vulnerabilities (the people and properties in harm’s way) need to be characterized (National Research Council, 2006). Pre-event public education is required to enable at-risk populations to correctly interpret: (1) natural cues from the environment (e.g., ground shaking from the earthquake) or (2) warnings from a technical detection system as a signal to evacuate to higher ground in a timely fashion. The threat detection component monitors the environment for threshold events using cues from natural and technical systems (Mileti, 1999; Mileti and Sorenson, 1990).

Once a significant tsunami is detected, the warning process needs to be managed. Tsunami information needs to be analyzed and decisions have to be made about the extent of the warning. Managers and decision makers issue warnings directly to the public. Ideally, officials managing the response also maintain situational awareness and information flow between the technical detection system and the public to update warnings and messages with the required protective actions to be taken. Because of the dominance of real-time communications, the Internet, and social networking, both the general public and media will increasingly access tsunami information directly from real-time information sources (e.g., the TWCs, seismometers, and water-level gauges) before local officials are able to respond. The public’s real-time access to different information sources, such as social media and networking systems, underscores the importance of public education to prepare both the public and the press for proper interpretation of information and response to detected hazards. An effective warning system monitors the public’s response and reactions in order to improve its processes for effective, understandable, actionable, reliable, and accurate warnings of impending danger. In the following chapters, the report covers the system components and compares the idealized system with current and/or planned efforts.

An integrated TWS has an impact on large populations and on a wide range of resources and, in the event of failure, has the potential to cause enormous economic, social, organizational, technological, and political losses. Although often seen as mainly comprising technical and technological elements, a warning system must, out of necessity, include the human dimension, such as people’s behavior, policies, procedures, and organizations. However, it is the human dimension that poses a significant challenge:

This involves the setting and running of national services (people), and the implementation of complex emergency-preparedness and awareness plans at the national and local levels to immediately inform every person of the threat. In the building of any early warning system, this is the difficult part. (Intergovernmental Oceanographic Commission, International Strategy for Disaster Reduction, and World Meteorological Organization, 2005).

CHALLENGES TO REDUCING THE NATION’S VULNERABILITY TO TSUNAMIS

Reducing the vulnerability of coastal settlements and infrastructure to tsunami risk poses some unique challenges. Although tsunamis can be devastating, as was seen during the 2004 Indian Ocean event, catastrophic tsunamis are relatively infrequent. This infrequency makes it more challenging to sustain the capacity to educate, warn, and prepare for this particular hazard. As discussed above, the history of tsunami warning and mitigation efforts in the United States shows that significant new funding is often made available only after a tsunami has devastated a coastal community and caused casualties. High funding levels and commitment to tsunami mitigation dissipate over time, leading to difficulties in maintaining efforts, knowledge, and lessons learned over time. Another challenge is the need to relay warnings from the fed-

eral government to state and local officials in just minutes (in the case of a near-field tsunami) or hours (in the case of a far-field tsunami). Sustaining the organizational preparedness and coordination across many jurisdictional boundaries presents a daunting challenge.

The committee recognizes that the nation’s tsunami detection, warning, and preparedness efforts originated in many diverse efforts distributed across several coastal states, and that attempts to integrate these distributed components into a coherent program have only recently begun. In particular, because tsunamis are rapid onset events, there is very little margin for error in the system before failure becomes catastrophic. An organization that operates in a low probability, high-risk environment, allowing few errors, is called an HRO (Roberts, 1990). HROs manifest a number of common properties: flexible and adaptable organizational structures, continually reinforced organizational learning, decision making that is both flexible and mobile, a strongly reinforced organizational culture, constant and effective communication, and trust among members of the system, particularly across organizations (Grabowski and Roberts, 1999; Grabowski et al., 2007). Because the committee identified the need for high-reliability operations in TWSs, the committee draws from the research literature on HROs (Roberts, 1990) and resilient systems (Hollnagel et al., 2008) to highlight particular characteristics that reduce the risks of failure in an idealized end-to-end warning system:

Situational Awareness in an Emergency: Because tsunamis are events that allow only minutes to hours for evacuation, a keen sense of situational awareness and the ability to respond quickly and effectively is required (Weick, 1990, 1993, 2003). HROs require decision making that is adaptable to change and surprise, and that is able to continually reassess needs across distributed organizations (Weick, 1993, 1998; Weick et al., 1999). Such is the case with the nation’s tsunami warning and preparedness efforts, where the TWCs, the state and local offices, and emergency managers and the affected public are geographically dispersed and often lack face-to-face contact. The dispersed and decentralized nature of the end-to-end tsunami warning and preparedness efforts make it a significant challenge to maintain awareness of the evolving situation during a crisis.

Learning and Training: To maintain situational awareness under changing conditions requires training. Therefore, an effective TWS requires that watchstanders, emergency managers, regulators, the public, and the media learn together, and engage in learning that enhances sense-making and developing alertness to small incidents that may cascade into much larger disasters (Weick, 1993; Farber et al., 2006). Because of the low frequency of tsunamis (e.g., California is issued an alert bulletin on average once every three years; Dengler, 2009), a TWS has few opportunities to learn from an event and therefore needs to learn from exercising the system through drills. Trial and error can be disastrous not only because disasters are rare, but also because in the absence of a major catastrophe to focus attention in the system, lessons learned from previous events may be forgotten or misapplied (March et al., 1991; Levitt and March, 1988; De Holan and Phillips, 2004). Learning in a high-reliability organization needs to be systematic, continually reinforced, measured, and made part of the system’s core values.

Fluid Organizational Structures: HRO structures are often adaptable and fluid, allowing the system to expand or contract in response to its environment (Roberts, 1990). TWSs with flexible organizational structures would be able to expand and contract resources in response to shifts and changes in environmental demands, disasters, or periods of slack resources. In the event of a tsunami, TWS managers need to grow effective, functioning response organizations in a period of less than 24 hours, and then adjust the organizational structures to the needs of the response (Tuler, 1988; Bigley and Roberts, 2001). The ability to provide varied organizational structures in response to environmental demands may be critical to the success of TWS organizations, similar to the way fire and emergency organizations expand and contract in response to fire demands (Grabowski and Roberts, 1999). Distributed information technology that connects the system responders can provide the technological glue that ties HRO members together, and fluid organizational structures can allow the organization to grow, expand, contract, and respond to changes in a dynamic, high tempo environment (Bigley and Roberts, 2001). Similar requirements for members and organizations in TWSs can be envisioned as tsunami conditions unfold.

Strong Organizational Culture: Schein (1992, 1996) defines “culture” as a set of basic tacit assumptions, that a group of people share, about how the world is and ought to be; it determines their perceptions, thoughts, feelings, and to some degree, their overt behavior. In many organizations, shared assumptions typically form around the functional units of the organization and are often based on members’ similar educational backgrounds or experiences (Grabowski and Roberts, 1996, 1997). HROs are characterized by strong cultures and norms that reinforce the organization’s mission and goals and that focus attention on procedures, policies, and reward structures consistent with the organization’s mission and safety (LaPorte and Consolini, 1991). HROs have cultures attentive to errors; cultures where closely held ideas about the organization, its mission, and member roles in reliability enhancement are articulated; cultures that encourage learning; and cultures where safe areas—for decision making, communication, and the like—are created as buffers (Weick, 1993). Constructs such as oversight and checks and balances reinforce the strong cultural norms of the HRO. Melding the varied cultures that integrate the system into a cohesive whole can be extremely difficult in distributed systems that are connected by linkages that can dissolve and wane as requirements, organizational structures, and political will change (Weick, 1987; Weick and Roberts, 1993; Grabowski and Roberts, 1999).

Managing decision making across organizations that report to different management structures is a challenge for highly dispersed efforts; this is certainly the case with U.S. tsunami detection, warning, and preparedness efforts. A particular challenge is that the federal government has responsibility to forecast and warn about potential hazards, yet local governments order evacuations. Failure to consider distributed decision making within groups and across multiple units can lead to lack of readiness for the next large-scale catastrophe; e.g., Hurricane Katrina (Roberts et al., 2005; Farber et al., 2006). Building good communication and trust aid in

effective decision making and can increase the likelihood of success in geographically dis-tributed organizations. Trust can be built by common training; opportunities for scientific and operational exchange; and workshops, conferences, exercises, and simulations that build community and coherence across distributed organizations.

TYING IT ALL TOGETHER: REPORT ROADMAP

In the following chapters, the committee assesses progress in the nation’s distributed tsunami preparedness, detection, and warning efforts and compares it to its vision of an idealized warning system ( Figure 1.3 ). Chapter 2 evaluates progress in hazard and vulnerability assessments and identifies potential improvements that could guide the nation’s tsunami risk-assessment efforts. Chapter 3 discusses education and outreach efforts and evaluates pre-event community and organizational preparedness and the coordination between the various entities at the local, state, and federal levels. Chapter 4 examines the technical hazard detection system, including the seismic and sea level sensor networks. Chapter 5 examines the TWCs’ operations and how technology and human capital are used to provide their functions. Appendices present supporting data on tsunami sources, hazard and evacuation maps, educational efforts, seismological methods, and several case-study tsunamis.

This page intentionally left blank.

Many coastal areas of the United States are at risk for tsunamis. After the catastrophic 2004 tsunami in the Indian Ocean, legislation was passed to expand U.S. tsunami warning capabilities. Since then, the nation has made progress in several related areas on both the federal and state levels. At the federal level, NOAA has improved the ability to detect and forecast tsunamis by expanding the sensor network. Other federal and state activities to increase tsunami safety include: improvements to tsunami hazard and evacuation maps for many coastal communities; vulnerability assessments of some coastal populations in several states; and new efforts to increase public awareness of the hazard and how to respond.

Tsunami Warning and Preparedness explores the advances made in tsunami detection and preparedness, and identifies the challenges that still remain. The book describes areas of research and development that would improve tsunami education, preparation, and detection, especially with tsunamis that arrive less than an hour after the triggering event. It asserts that seamless coordination between the two Tsunami Warning Centers and clear communications to local officials and the public could create a timely and effective response to coastal communities facing a pending tsuanami.

According to Tsunami Warning and Preparedness , minimizing future losses to the nation from tsunamis requires persistent progress across the broad spectrum of efforts including: risk assessment, public education, government coordination, detection and forecasting, and warning-center operations. The book also suggests designing effective interagency exercises, using professional emergency-management standards to prepare communities, and prioritizing funding based on tsunami risk.

READ FREE ONLINE

Welcome to OpenBook!

You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

Do you want to take a quick tour of the OpenBook's features?

Show this book's table of contents , where you can jump to any chapter by name.

...or use these buttons to go back to the previous chapter or skip to the next one.

Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

Switch between the Original Pages , where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

To search the entire text of this book, type in your search term here and press Enter .

Share a link to this book page on your preferred social network or via email.

View our suggested citation for this chapter.

Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

Get Email Updates

Do you enjoy reading reports from the Academies online for free ? Sign up for email notifications and we'll let you know about new publications in your areas of interest when they're released.

Talk to our experts

1800-120-456-456

• World Tsunami Awareness Day: Essay for Students in English

This is an essay on the topic "World Tsunami Awareness Day," a day that resonates with the profound force of Tsunamis and the collective effort to understand, prepare, and unite. Whether you're seeking to grasp the concept or preparing for school projects and competitions, this essay is a valuable resource that you can refer to anytime, anywhere.

Essay on “World Tsunami Awareness Day”

“ Title: Riding the Wave of Knowledge: World Tsunami Awareness Day

Each November 5th , the world unites to honor World Tsunami Awareness Day . We reflect on Tsunamis, nature’s most powerful and unpredictable force. This day is more than a calendar marker; it reminds us of nature’s might and the need to collaborate to prepare.

What is a Tsunami?

Tsunamis are like ocean giants, but not the friendly kind you see in cartoons. They are massive waves triggered by underwater earthquakes, volcanic eruptions, or landslides. These waves can travel across entire oceans and, when they reach the coast, they become towering walls of water, causing immense destruction.

November 5th: A Day of Remembrance

You might wonder, why November 5th? It’s not just a random date; it’s a day we remember as a significant event. Back in 1854, Japan experienced a massive Tsunami known as the Nanki Tsunami. This devastating wave caused a lot of damage and took many lives. This historical event is why the United Nations chose this date to raise awareness about Tsunamis.

Theme for 2023: “Fighting Inequality for a Resilient Future”

This year, World Tsunami Awareness Day has a special theme: " Fighting Inequality for a Resilient Future ." But what does that mean? It means that we want to ensure that everyone, no matter where they live or their background, has access to knowledge and resources to stay safe from Tsunamis. It's about being fair and making sure everyone has an equal chance to be prepared.

Real-Life Impact

Tsunamis are not just something we read about in books. They have destroyed many parts of the world. Take, for example, the Indian Ocean Tsunami in 2004. It was one of the deadliest Tsunamis in history, affecting 14 countries and taking the lives of over 230,000 people. This tragic event emphasized the need for a global early warning system, leading to the establishment of the Indian Ocean Tsunami Warning and Mitigation System.

Building Resilient Communities

So, what can we do about it? It's all about building resilient communities. Resilience means being able to bounce back from challenges and disasters. It involves creating plans, early warning systems, and knowing how to respond. For instance, Japan, a country frequently facing Tsunamis, has one of the most advanced Tsunami warning systems in the world. Their well-practiced evacuation plans have significantly reduced the impact of Tsunamis on their coastal communities.

The Role of Education

Education plays a vital role in raising awareness about Tsunamis. Many schools teach students about the science of Tsunamis, how to recognize warning signs, and what to do in case of a Tsunami. It's like having a superhero team to help us stay safe.

Conclusion for Essay

World Tsunami Awareness Day is not just another day on the calendar. It's a day of reflection and action. It reminds us of the incredible power of Tsunamis and the need to be prepared. So, let's come together, learn, and work towards building resilient communities that can face the unpredictable might of Tsunamis. As students, we have the power to make a difference by spreading the word and being ready.

World Tsunami Awareness Day serves as a beacon of awareness and preparedness in the face of nature's might. It's a global call to action, a moment of reflection, and a shared endeavor to build resilient communities. 

Whether you're looking to understand the concept or gearing up for school projects and competitions, remember that this essay is a reference you can turn to anytime, anywhere. As you ride the wave of knowledge, let's stand together in the face of this awe-inspiring natural force.

FAQs on World Tsunami Awareness Day: Essay for Students in English

1. How does a Tsunami affect human life?

Tsunamis can cause widespread loss of life, injury, and damage to property and infrastructure.

2. Where can I find an Essay on World Tsunami Day 2023?

You can find an essay on the “World Tsunami Awareness Day 2023” on Vedantu’s website.

3. Tsunami information in 150 words?

Tsunamis are giant waves that can be caused by earthquakes, volcanic eruptions, or landslides underwater. They can travel very fast, up to 500 miles per hour, and can be over 100 feet tall. Tsunamis can cause widespread damage and loss of life, so it is important to be prepared if you live in an area that is at risk.

4. What date is Tsunami Day celebrated?

The 5th of November is celebrated as World Tsunami Day.

5. From which language was the word Tsunami taken info?

Tsunami is a Japanese word. Tsu means port or harbor, and nami, means wave. 

• Skip to main content

India’s Largest Career Transformation Portal

Essay on Tsunami for Students in English | 500+ Words Essay

January 1, 2021 by Sandeep

Essay on Tsunami: A sudden, unexpected series of ocean waves of high risen wavelengths are called tsunami waves. They are strong currents of water waves that rush through inland spaces, flood nearby areas and last for a long time. They are seismic waves that trigger landslide undersea and force themselves through any obstacle on their way. Large volumes of water are displaced at great transoceanic distances at high speeds.

Essay on Tsunami 500 Words in English

Below we have provided Tsunami Essay in English, suitable for class 5, 6, 7, 8, 9 and 10.

A tsunami is a series of fierce waves generated by the displacement of water. They occur in substantial water bodies due to earthquakes, volcanic eruptions and underwater explosions. Tsunamis are also oftenly referred to as tidal waves. The waves are very high in magnitude as well as their length, and they can be immensely destructive.

Japan is the country which has recorded the most significant number of tsunamis. The tsunami generated in the Indian Ocean in the year 2004 is still considered as the most upsetting tsunami taking more than two hundred thousand lives. Tsunamis are quite rare in occurrence as compared to other natural disasters , but they are equally damaging.

Causes of Tsunami

The leading cause of a tsunami is attributable to an earthquake . However, even volcanic eruptions, landslides and comets or other heavenly bodies hitting the sea can be a source. When the tectonic plates of the earth positioned under the sea are disturbed, an earthquake takes place, causing the seawater to displace and erupt in sudden waves. These waves move further and further towards the shores. They can go unnoticed in the deep ocean but become more prominent as the water becomes shallow.

Landslides are another prominent cause of a tsunami. When heavy debris falls without warning with massive force into the sea, it causes a tremendous ripple effect. This ripple effect thus, causes tidal waves to form, which ultimately rise towards the land and cause massive destruction. During the eruption of a volcano on land, debris falls with a great thrust into the water body, causing the same ripple effect. Volcanoes can be underwater as well. They are known as submarine volcanoes. Tsunamis can further occur as a result of meteorological activity and human-made triggers.

Effects of Tsunami

When water washes away the shores with such colossal force, it damages the sewage system and freshwater. It also causes water fit for drinking to erode and contaminate. Because of the water being stagnant and polluted, numerous diseases like malaria affect a large number of people. They become ill, and infections spread quickly. A tsunami may even destroy nuclear plants which result in emittance of harmful radiations. These radiations are fatal to the health of every living organism. Mass evacuations become necessary in areas exposed to radiations because they can result in cancer, death and can even affect the DNA structures.

The saddest effect of a tsunami is the loss of lives in huge numbers. Tsunamis hit suddenly, with almost no warning and hence people get no time to escape it or run away. They drown, collapse, are electrocuted, etc. Tsunamis not only cause massive destruction of life but also degrade the environment in a gigantic way. It uproots trees and destroys pipelines which lead to the release of dioxides, raw sewage and other pollutants into the atmosphere. When these hazardous pollutants are washed into the sea, they also cause unbearable damage to the aquatic underwater life.

When the waves of a powerful tsunami smash the shores, they destroy trees, cars, buildings, telephone lines, pipelines and other man-made equipment into bits and pieces. Poverty rises in areas which get most affected by the wrath of tsunamis. The governments are also able to do little for their betterment immediately due to the high funding requirement and expenses.

Prevention of Tsunami

The government can invest in building strong and high protective infrastructure which can withstand the force of a tsunami. The length should be so tall, that the most upper wave of the tsunami cannot over top it. Also, heavy construction and livelihood activities in tsunami-prone areas can be avoided. The local authorities can install an efficient and fast early warning system. This would help to get all the people on alert. This way, more and more people would evacuate or leave the areas of danger, and human life destruction could be minimised.

Educating people and making them aware of the effects and impact of a tsunami is exceptionally crucial. They should be taught about the early warning signals of a tsunami and how to identify them. They should also learn how to be fully prepared in tough times like these instead of panicking and rapidly running around. Planting the coastal regions and boundaries with trees such as Mangroves which can absorb tidal wave energy can be another option. These can help to reduce the impact of a tsunami and curb the levels of destruction caused.

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• ADVERTISEMENT FEATURE Advertiser retains sole responsibility for the content of this article

Tsunami research improves coastal protection

Produced by

The future of many coastal megacities depends upon reliable disaster prediction, protection and prevention strategies as global warming is projected to bring stronger storms, risking millions of lives.

Palu, Sulawesi in Indonesia experienced widespread damage after a tsunami and earthquake in 2018. ©Dhody wachyudi/Shutterstock

On 11 March 2011, the devastating Tohoku tsunami was triggered by an earthquake off Japan, killing more than 15,000 people. Japan experiences more earthquakes than anywhere in the world, but catastrophic tsunamis and storm surges are a global problem; from the 2004 Indian Ocean tsunami, to Typhoon Haiyan that struck the Philippines in 2013.

After the 2011 catastrophic tsunami, Waseda University established the Center for Research on Reconstruction from the Great East Japan Earthquake and called for research proposals for on reconstruction of affected areas.

Professor Tomoya Shibayama from the Faculty of Science and Engineering, led a project on infrastructure restoration and disaster management systems that focussed on tsunami responses to support design of new towns and fishing villages at affected sites.

Beyond the science of tsunamis, Shibayama has helped transform Waseda into a base for studying natural hazards, from storms surges to volcanic eruptions.

Waseda’s tsunami wave generator enables researchers to conduct 3D experiments.

Shibayama, when he joined Waseda in 2009, brought 30 years of experience in coastal disaster research. By sharing worldwide his team’s discoveries and damage limitation strategies, he aims to help prevent future disasters. His team’s work benefits from the university’s commitment to tackle global problems through investing in cutting-edge techniques, he says.

Between 2013 and 2018, Shibayama’s team attracted additional funding from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) that supercharged their coastal protection research. “Through international collaboration, we created new simulation models, conducted field surveys, and developed new laboratory techniques,” he explains. The laboratory at Waseda includes a tsunami-storm surge basin, and a wave flume with controllable wave generators. “We have advanced apparatus for measuring water velocity and pressure fields of tsunamis, storm surges, and wind-driven waves,” says Shibayama.

As ocean temperatures rise due to global warming, coastal cities need to understand changing storm behaviour to assess existing defences. A team led by Shibayama’s doctoral student, Ryota Nakamura, now an associate professor at Niigata University, used atmospheric and ocean models developed at Waseda to simulate typhoons off mainland Japan — and the resultant height of storm surges in Tokyo Bay — under future climate scenarios. The study revealed the need to raise current sea walls and dykes to protect Tokyo from future higher, more powerful storm surges.

Lessons of other shores

In 2018, Shibayama and an international team conducted field surveys in Palu Bay in Indonesia, a month after a major tsunami, to assess causes of damage to the coastal communities.

“Before visiting, we collected satellite images and YouTube footage,” says Shibayama. “Once there, we measured the distribution of the maximum tsunami flood height and used a drone to take images. We mapped the bottom of Palu Bay and located landslides that contributed to the tsunami.”

Their observations, published in Pure and Applied Geophysics in 2019, revealed the earthquake triggered perilous mudslides and the narrow bay reflected and superimposed waves to increase the height of the tsunami, which landed several metres higher than expected. The Sulawesi earthquake killed more than 4,000 people and highlighted the importance of emergency preparation and communication.

Shibayama has helped 24 international PhD students, many of whom returned to their home countries to share their expertise. Rafael Aranguiz, now an associate professor at Universidad Católica de la Santísima Concepción, studied tsunami disasters in his home country of Chile. The findings from his doctorate at Waseda enabled him to propose suitable defences on the Chilean coast.

Human Behaviour

In 2018, a study by Waseda researchers of human behaviour on the death toll modelled the tsunami evacuation by locals, tourists and people on Yuigahama beach in Kamakura, Japan.

Detached breakwaters are installed in the tsunami basin to stop intrusion of a tsunami.

The researchers simulated seven tsunami flood events caused by different types of earthquake to estimate the casualties under various evacuation scenarios. Providing information and routes to safe places proved particularly useful. Simply rushing to higher ground, which most people do instinctively, was insufficient to save lives. “Local residents know the area and if they give instructions to tourists, we can improve evacuation procedures and therefore survival,” adds Shibayama, who advises the Kanagawa government about tsunami and storm surge prediction.

Future coasts

Shibayama hopes his research, including a 2020 paper in the Coastal Engineering Journal , helps Japan better prepare for disaster. “We expect rising storm surge heights with global warming,“ he says, “and we will improve coastal protection structures accordingly. Yet, we expect residential areas will need to shift as coastal threats increase.”

International collaborations underpin Waseda research, and Shibayama, with the University of Ottawa is studying the Arctic Ocean, where disappearing sea ice could increase high wind waves, exacerbating coastal erosion. “Methods developed at Waseda, helps us understand this drastic change in the disaster environment,” he says.

Related Articles

Quick links

• Explore articles by subject
• Guide to authors
• Editorial policies

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.

Also check:

• 10 Lines on Tsunami
• Paragraph on Tsunami
• Speech on Tsunami

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.

That’s it! I hope the essay helped you.

If you’re looking for more, here are essays on other interesting topics:

• Essay on Trekking
• Essay on Tokyo Olympics
• Essay on Titanic

Apart from these, you can look at all the essays by clicking here .

Happy studying!

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

• IOC Tsunami
• You are here: Home > General Info > What to Do? > Safety Rules > Tsunami Safety Rules
• Contact ITIC
• World Tsunami Day
• Hawaii Information
• American Samoa Info
• About Tsunamis
• Am I in Danger?
• What to Do?
• Aware, Educate
• Photo, Video, Graphic
• Quick Info - Media
• Current Warnings
• About Warnings
• Tsunami Events
• Earthquake Monitors
• Sea Level Monitors
• Tools & Products
• ITST Tsunami Survey
• Marine Ports Guide
• Vertical Evac Guide
• Global System
• Pacific (PTWS)
• Caribbean (CARIBE-EWS)
• Info Centers
• ITIC Training
• Tsunami Exercises
• UNESCO/IOC Tsunami Ready Programme

WHAT TO DO? TSUNAMI SAFETY RULES

IOC Tsunami Information Centres

        ITIC                   CTIC         ITIC-CAR  

      IOTIC               NEAMTIC

Quick Links

Current Warnings Most Recent Tsunami

Tsunami Sources, Significant Earthquakes, Significant Volcanic Eruptions, Tsunami Icosohedron Globe.

Available in English, Spanish, French, Chinese.

Available in English, Arabic, Spanish, French, Bahasa, Chinese. 

DVD copies for computers available from the ITIC ( [email protected] ).

Learn the basics of tsunamis. Available in English, Samoan.

• Play & Activities
• Life Skills
• Learning & Education
• Play & Learning

• Growth & Development
• Rhymes & Songs
• Preschool Locator

Essay On Tsunami – 10 Lines, Short & Long Essay For Children

Key Points To Remember: Essay On Tsunami For Lower Primary Classes

10 lines on tsunami for kids, a paragraph on tsunami in english for children, short essay on tsunami for kids, long essay on tsunami for children, what will your child learn from this essay, interesting facts about tsunami for kids.

The word ‘Tsunami’ is of Japanese origin, which means harbour wave. A tsunami is the repetition of long-wavelength water waves triggered due to quakes and volcanic eruptions in ocean beds. If the earthquake fails to cause a tsunami inside the ocean, it will mostly cause a landslide. This tsunami essay for classes 1, 2 and 3 will help your child learn about new things. A tsunami essay in English will also improve ability to convert thoughts into words, positively impacting communication and vocabulary.

A topic like tsunami isn’t a very easy topic to write about. Children might need the assistance of parents or teachers to write about tsunamis. Here are a few key points to remember when writing a composition on tsunami for lower primary classes:

• Use videos or pictures while explaining tsunamis to kids. Visual aids help in better memorisation.
• Keep the content crisp and clear. A tsunami is a phenomenon that involves geographical terms. So, keep in mind to use simple language.
• Encourage your child to write their essay independently once the basics are covered.

What is a tsunami? How does it occur, and what is its impact? Get answers to these questions from the essay for class 1 and 2 kids on tsunamis. Mentioned below are a few lines on tsunami:

• Tsunamis are natural disasters that cause harm to the environment.
• It happens due to an earthquake underwater.
• These occur unexpectedly.
• Volcanic eruptions, plate shifting, the sinking of the earth, etc., are other reasons for tsunamis.
• The term tsunami means harbour waves.
• It has a series of waves with a high wavelength, capable of serious damage.
• The waves created in seas and oceans move towards the land and destroy buildings, homes, forests, etc.
• Landslides also lead to tsunamis.
• Most tsunamis often happen in the Pacific ocean.
• India experienced a similarly destructive Tsunami in 2004.

Do you want to read a short paragraph on tsunamis for children? Then, you are at the right place. Given below is a template for reference:

A tsunami is a series of waves of high wavelengths that cause water to move toward the land. It happens due to earthquakes whose main point is in the water/ocean. Greeks were the first to notice the effects of tsunamis. Sudden volcanic eruptions in the ocean beds, the sinking of the earth, etc., are the other major reasons for tsunamis. Like any other natural calamity, it causes widespread damage to human lives, buildings and trees. Underwater explosions can lead to tsunamis as well. The Pacific Ocean is known to be the hub of tsunamis. Ports and harbours get affected badly by tsunamis.

Looking for a simple-written short essay for classes 1,2 and 3 on tsunamis for kids to understand? Well, search no further. Given below is the template for the same:

A tsunami is defined as a series of waves of high wavelengths that cause water to move toward the land. It happens due to earthquakes whose main point is in the water. Greeks were the first to study the effects of tsunamis, and the only difference between earthquakes and tsunamis is that the latter happens in water. Tsunamis are called seismic waves. We should know that all seismic waves are tsunamis, but earthquakes are not the sole cause of all tsunamis. It also occurs due to sudden volcanic eruptions in the ocean beds, the sinking of the earth, etc. Like any other natural calamity, it causes widespread damage to human lives, public and private properties, and forests. Underwater explosions can lead to tsunamis as well. The Pacific Ocean is known to be the hub of tsunamis. During tsunamis, marine life is also get affected.

Natural calamities like tsunamis occur due to various reasons and cause damage to living and non-living. Here is an essay for class 3 kids on the causes, impacts and history of tsunamis.

History of Tsunami

According to legend, the Greek historian Thucydides suggested that there might be a connection between undersea earthquakes and tsunamis. But until the 20th century, knowledge of the causes and nature of tsunamis was limited. Ammianus, a Roman historian, characterised the sequence of events leading up to a tsunami as an earthquake, a quick retreat of the sea, and then a massive wave. The highest ever tsunami took place in a bay along the coasts of Alaska on July 9th, 1958.

What are the Causes and Effects of Tsunami?

Causes of Tsunami 

• Earthquakes and Landslides:  Shifts in tectonic plates cause earthquakes, and when the main point is in the water, a tsunami is triggered. Sometimes landslides induced by earthquakes lead to these tidal waves.
• Volcanic Eruptions in Sea Beds:  Volcanic eruptions in sea beds are another cause of these high wavelength waves.
• The Sinking of The Earth:  Changes in the earth’s crust or interiors often lead to the sinking of the earth, and this sudden shift can trigger a tsunami.
• Underwater Explosions:  Incidents like meteor collisions with the earth, or chunks of ice breaking off from glaciers lead to underwater explosions.

Effects of Tsunami

• Boats and Ships Sink:  The crashing of such high waves causes widespread damage to boats and ships off the coast.
• It Ruins Buildings, Trees and Houses:  Since the water moves towards the land and is of high velocity, it can destroy homes, uproot trees and displace vehicles.
• Causes:  As in the case of any natural calamity, a tsunami also takes a toll on people’s lives.

How Can Tsunami Be Prevented?

The effects of a tsunami can be reduced by avoiding inundation areas, slowing down water by building ditches, slopes, etc. and steering water to strategically placed walls or structures. An alert well ahead of time can also reduce the damage percentage.

How To Prepare for a Tsunami Disaster?

• To escape a tsunami, go 100 feet above sea level or 2 miles away.
• Often there are weather reports and cautionary warnings for a tsunami. Please take care to follow them.
• Every foot inland or upward is sure to make a difference!
• If you can see the wave, you are too close for safety!

Your child will learn about the causes, history and effects of natural disasters such as tsunamis. They will also understand essay writing and its ways better.

• The word tsunami means harbour wave in Japanese.
• The Pacific Ocean is the hub of tsunamis.
• The first wave of a tsunami is never the biggest.
• The series of waves generated by a tsunami is called a wave train.
• Often called tidal waves, tsunamis are not related to ocean tides.

What is the Difference Between Earthquake and Tsunami?

The major difference between an earthquake and a tsunami is that tsunamis are triggered by earthquakes whose main point is in the oceans or seas. And earthquakes happen on the land.

Topics like composition on tsunamis create awareness about natural calamities and the damage these can cause to humans. Teach your child about possible effects and help them learn new things.

Save The Environment Essay for Kids Essay On Nature for Class 1, 2 and 3 Children Essay on Importance of Water for Lower Primary Classes

• Essays for Class 1
• Essays for Class 2
• Essays for Class 3

5 Recommended Books To Add To Your Child’s Reading List and Why

5 absolute must-watch movies and shows for kids, 15 indoor toys that have multiple uses and benefits, leave a reply cancel reply.

Log in to leave a comment

Most Popular

The best toys for newborns according to developmental paediatricians, the best toys for three-month-old baby brain development, recent comments.

FirstCry Intelli Education is an Early Learning brand, with products and services designed by educators with decades of experience, to equip children with skills that will help them succeed in the world of tomorrow.

Story Related Activities Designed to Bring the Story to Life and Create Fun Memories.

Online Preschool is the Only Way Your Child's Learning Can Continue This Year, Don't Wait Any Longer - Get Started!

©2021 All rights reserved

• Privacy Policy
• Terms of Use

Welcome to the world of Intelli!

We have some FREE Activity E-books waiting for you. Fill in your details below so we can send you tailor- made activities for you and your little one.

Welcome to the world of intelli!

FREE guides and worksheets coming your way on whatsapp. Subscribe Below !!

THANK YOU!!!

Here are your free guides and worksheets.

An official website of the United States government

Here’s how you know

Official websites use .gov A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS A lock ( Lock A locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Prepare Now

Survive During

Be Safe After

Related Content

If you are a disaster survivor, please visit FEMA.gov for up-to-date information on current disaster declarations. If you have questions about your disaster assistance application, you can call (800) 621-3362, visit disasterassistance.gov or use the FEMA mobile app .

A tsunami is a series of enormous ocean waves caused by earthquakes, underwater landslides, volcanic eruptions or asteroids. A tsunami can kill or injure people and damage or destroy buildings and infrastructure as waves come in and go out. Tsunamis can:

Travel 20-30 miles per hour with waves 10-100 feet high.

Cause flooding and disrupt transportation, power, communications and the water supply.

Happen anywhere along U.S. coasts. Coasts that border the Pacific Ocean or Caribbean have the greatest risk.

IF YOU ARE UNDER A TSUNAMI WARNING:

• If caused by an earthquake,  Drop, Cover, then Hold On to protect yourself from the earthquake first.
• Get to high ground as far inland as possible
• Be alert to signs of a tsunami, such as a sudden rise or draining of ocean waters.
• Listen to emergency information and alerts. Always follow the instructions from local emergency managers.
• Evacuate: DO NOT wait! Leave as soon as you see any natural signs of a tsunami or receive an official tsunami warning.
• If you are in a boat, go out to sea.

Prepare NOW

• Learn the signs of a potential tsunami, such as an earthquake, a loud roar from the ocean, or unusual ocean behavior, such as a sudden rise or wall of water or sudden draining of water showing the ocean floor.
• Know and practice community evacuation plans. Some at-risk communities have maps with evacuation zones and routes. Map out your routes from home, work and play. Pick shelters 100 feet or more above sea level, or at least one mile inland.
• Create a family emergency communication plan that has an out-of-state contact. Plan where to meet if you get separated.
• Sign up for your community’s warning system. The Emergency Alert System (EAS) and National Oceanic and Atmospheric Administration (NOAA) Weather Radio also provide emergency alerts.
• Consider earthquake insurance and a flood insurance policy through the National Flood Insurance Program (NFIP). Standard homeowner’s insurance does not cover flood or earthquake damage.

Survive DURING

• If there is an earthquake and you are in a tsunami area, protect yourself from the earthquake first. Drop, Cover, and Hold On. Drop to your hands and knees. Cover your head and neck with your arms. Hold on to any sturdy furniture until the shaking stops. Crawl only if you can reach a better cover, but do not go through an area with more debris.
• When the shaking stops, if there are natural signs or official warnings of a tsunami, move immediately to a safe place as high and as far inland as possible. Listen to the authorities, but do not wait for tsunami warnings and evacuation orders.
• If you are outside of the tsunami hazard zone and receive a warning, stay where you are unless officials tell you otherwise.
• Leave immediately if you are told to do so. Evacuation routes often are marked by a wave with an arrow in the direction of higher ground.
• If you are in the water, then grab onto something that floats, such as a raft or tree trunk.
• If you are in a boat, face the direction of the waves and head out to sea. If you are in a harbor, go inland.

Be Safe AFTER

• Listen to local alerts and authorities for information on areas to avoid and shelter locations.
• Save phone calls for emergencies. Phone systems often are down or busy after a disaster. Use text messages or social media to communicate with family and friends.
• Avoid wading in floodwater, which can contain dangerous debris. Water may be deeper than it appears.
• Be aware of the risk of electrocution. Underground or downed power lines can electrically charge water. Do not touch electrical equipment if it is wet or if you are standing in water.
• Stay away from damaged buildings, roads and bridges.
• If you become injured or sick and need medical attention, contact your healthcare provider and shelter in place, if possible. Call 9-1-1 if you are experiencing a medical emergency.
• Document property damage with photographs. Conduct an inventory and contact your insurance company for assistance.
• Tsunami Safety Graphics
• Tsunami Information Sheet  (PDF)
• Protective Actions Research for Tsunami
• NOAA Tsunami program
• American Red Cross Tsunami Preparedness
• Tsunami Safety (weather.gov)

Last Updated: 03/21/2024

Return to top