Tsunamis

Tsunami are huge waves that form in large bodies of water (e.g., oceans, seas, large lakes), that are caused by abrupt vertical displacement of a huge column of water. The displacement can be caused by naturally occurring events such as earthquakes, landslides, volcano eruptions, etc., and even sometimes from underwater explosions. These can become natural disasters devastating to the people and properties along the shore lines where they ultimately appear, sometimes in waves as big as hundreds of feet high or higher.

9,414 Questions
Tsunamis

What causes a tsunami?

THE CAUSES OF TSUNAMI

A short explanation of causes:

Tsunami (pronounced su-nah'-me) are huge ocean waves caused by natural forces like underwater earthquakes. Tsunami are caused when the forces of these phenomena rapidly displace large amounts of water.

Most tsunami occur when there is an earthquake or volcanic eruption in the sea or ocean. This is caused when there are plate boundaries that are meeting in plate tectonics processes. This will cause shock waves to be radiated out of the epicenter. This natural event will cause a rise or fall of the seabed. This will create a wave deep in the ocean (or less frequently in other large body of water).

Tsunami can also be caused by landslides, such as a cliff-side of a mountain near shore that falls into a large body of water or ocean.

Powerful bombs, like nuclear bombs, are tested, dropped, or detonated in the sea or ocean and can cause shock waves to be radiated out that move the ocean waters in waves as described above.

They also occur when large asteroids fall into the water. This is extremely rare, and the asteroids must be very large to cause a large water displacement to form a tsunami wave. But they are known to have occurred. Meteorites will not cause high waves as they are usually much smaller than asteroids by the time they have been burned in the atmosphere on the way to the surface.

A longer, more in depth answer:

The huge waves called tsunami are caused by the abrupt vertical displacement of a large volume of a body of water, usually from natural sources of kinetic energy (such as the force of large earthquakes near the shore or underwater). These forces produce a wave that shifts not just a few meters of surface water, but the entire column of water from the floor to the surface. They contain enormous amounts of energy. Earthquakes that cause tsunami often occur offshore at tectonic plate subduction zones. As the sea floor snaps up in response to the tectonic plate movement and subsequent earthquake, the tsunami wave is formed and moves out from the source of the displacement. The wave increases in height as it enters more shallow waters close to land.

They can occur in any large body of water, even in large lakes. An example is the mega-wave that formed when the volcano erupted at Mount St. Helens in the US in 1980. The eruption caused a massive landslide into Spirit Lake and that caused the mega-wave.

To better understand how a tsunami forms, try this experiment:

Get in a pool or the bath tub and put your hand a good ways down and then pull it up quickly but not out of the water, pull up strong but don't break the surface and watch the result. Not exactly a tsunami, but a simple version of the science.

SUMMARY:

Most tsunami occur when there are underwater seismic events such as an underwater earthquake or volcanic eruption. This normally occurs along plate boundaries. Subduction in convergent boundaries accounts for most tsunami. Subduction occurs when one plate dives under another that is blocking its movement. This will cause shock waves to be radiated out of the epicenter. There will be a rise or fall of the seabed. This displacement of the sea floor will create a wave which cannot be clearly detected from shore at first. These waves can travel at speeds up to 700 mph (i.e. the speed of sound in water) deep in the ocean or other large body of water. As the wave gets nearer to the shore, the wave will compress and gain height in the shallower water. The waves can be up to 100 ft. (30 m) or more when they come ashore.

Tsunami can also occur because of landslides or when asteroids (or very large meteorites) fall into large bodies of water. This is extremely rare, and they must be very large to cause a large enough water displacement to form a massive tsunami wave.

DETAILS:

Natural Causes

Besides earthquakes, these waves can also be caused by the forces of other natural phenomena and seismic events that move the tectonic plates, or that directly move the undersea water, or smash into the water surface from above in such a way as to rapidly displace the water.

When it happens in a sea, the sea floor may be deformed from below pushing the water up, or the water can be displaced from an impact coming down on the sea surface from above. Some of the natural causes, other than tectonic plate movements resulting in earthquakes, are huge landslides and other mass movements above or below the water. Sometimes a small underwater earthquake will trigger a landslide that causes a tsunami.

Volcano eruptions in or near the ocean can produce water displacement from underwater or from impacts from above by huge pieces of falling debris from explosions as a volcano erupts along a coastline or near a large lake.

Another cause from natural events is an ocean impact by rare large meteorites or asteroids. This is extremely rare, and they must be very large to cause a large water displacement to form a wave. Meteorites will not cause high waves as they are usually much smaller than asteroids.

Since these natural phenomena can be the causes, it means that tsunami have the potential to be formed anywhere in any large body of water at unpredictable times and without time for any warnings.

Unnatural Causes

An unnatural event with potential to cause tsunami is the detonation of underwater explosions (including detonations of underwater nuclear devices).

STILL MORE DETAILED INFORMATION ABOUT TSUNAMI:

The name

The word tsunami is a Japanese term. Japan is one of the most common locations for tsunami. The literal translation in English is "wave harbor" meaning "harbor wave". This name came from the fact that they only become visible as huge waves after arriving in shallower waters near shores and harbors, and therefore, they were originally believed to have originated in the harbor. The word tsunami has been used long enough that it has been adopted into most languages rather than being translated.

The Japanese word does not have a plural form and tsunami is used both for singular and plural in English in many locations. However, it has become accepted over time to say "tsunamis" for the plural in English.

Many early geological, geographical, and oceanographic texts refer to tsunami as "seismic sea waves."

They are sometimes mistakenly called "tidal waves," but tsunami have no relationship to the tides other than looking similar but smaller and generating some similar effects on land with flooding and devastation.

Tsunami are also sometimes incorrectly called "storm surges", which are also different wave phenomena. Tsunami have no relationship to weather. They are not caused by storms, cyclones, hurricanes, or high winds.

Tectonic plate action

Tsunami are commonly caused by seismic activity of tectonic plates (most often earthquakes). As such, they are often found around the Pacific Rim, a region of high tectonic activity in the Pacific Ocean.

A Tsunami can be caused when a tectonic plate in the earth's crust is subducted by another plate, which releases a lot of tensive (potential) energy, in an earthquake. Movement of tectonic plates can cause an earthquake that sends out jolts of seismic activity. Large vertical movements of the earth's crust can occur at plate boundaries. This will cause shock waves to be radiated out of the epicenter. These jolts then can push a tectonic plate under the sea floor, or over or under another plate. The earthquakes can form anywhere there is stress in a tectonic plate, but notably on plate boundaries. Plates interact along these boundaries called faults. Seismic activity is not, however, limited to boundaries of these plates. Tsunami can be formed if there is a very big earthquake any place in a plate that disrupts a water column in a large body of water.

Subduction in the convergent plate boundaries is said to account for most of the tsunami. This natural event will cause a rise or fall of the seabed. When large areas of the sea floor elevate or subside, a tsunami can be created.

This will create a wave deep in the ocean which cannot be clearly discerned from shore. This massive underwater wave transforms when it hits the shoreline and has nowhere else to go but up. This then pushes the water on the surface up, forming the massive wave.

Earthquakes

The Greek historian Thucydides was the first to relate tsunami to submarine earthquakes.

Subduction earthquakes are particularly effective in generating tsunami. In the case of earthquake-generated tsunami, there is a major disturbance under water causing the water column to rise as the earthquake uplifts or causes subsidence of the sea floor.

When the sea bed is lifted as a result of an earthquake, the water is also lifted. The size of the wave depends on how high and over how big an area the seabed was lifted. Some say the earthquake size must be at least 6.0 on the Richter scale to create a tsunami.

Landslides

Tsunami can be caused by very large landslides either falling into the water from above or by an underwater landslide pushing a column of water from below the surface. These mechanisms causing submarine slumps of material, or landslides of huge parts of a mountain or cliff side near shore, can occur without an earthquake, or at least without a significant one. Super marine landslides and cosmic-body impacts disturb the water from above as momentum from falling debris is transferred to the water into which the debris falls. Generally speaking, tsunami generated from these mechanisms, unlike the Pacific-wide tsunami caused by some earthquakes, dissipate quickly and rarely affect coastlines distant from the source area.

Submarine landslides, which often accompany large earthquakes, as well as resulting collapses of volcanic edifices, can also disturb the overlying water column as sediment and rock slump down-slope and are redistributed across the sea floor.

Another type of landslide that can produce tsunami involves the debris delta from a river system that eventually becomes unstable and slides off, thus displacing a large body of water. The rebound to this can cause a large enough surge to be a tsunami, and one with little warning.

Other similar causes in the colder oceans are huge avalanches or glacier calving.

Volcanoes

Tsunami can be generated when a violent volcano eruption on land occurs near a large body of water. Sometimes huge chunks of solid rock burst out of a volcano and fall into the nearby ocean or lake making a tsunami. Similarly, volcano eruptions can cause tsunami when they explode undersea. A violent submarine volcanic eruption can create an impulsive force that uplifts the water column and generates a tsunami.

Asteroids

Tsunami can also occur when large asteroids fall into the water. This is extremely rare, and the asteroids must be huge to cause a large enough water displacement to form a tsunami wave. But they are known to have occurred. Some geologists believe as recently as the early 1700s an asteroid impact off the Pacific Northwest coast of North America may have created a tsunami that reached Japan.

These produce a wave that shifts not just a few meters of surface water, but the entire column of water from the floor to the surface. They contain enormous amounts of energy. Tsunami caused by an asteroid impact could be a much higher and more devastating wave, depending on the asteroid's size. Fortunately such occurrences don't happen as frequently as those caused by earthquakes, volcanoes and underwater landslides.

Meteors

An even more rare cause is a meteorite hitting Earth. Meteorites will not cause waves as high as those caused by asteroids since they are usually much smaller bodies. There are estimates that the space rocks would have to have a diameter of between about 165 feet (50 meters) and 490 feet (150 meters). Any smaller and the rock would have exploded before hitting Earth or Earth's waters.

Underwater Explosions

Tsunami can also occur when powerful bombs, like nuclear bombs, are tested, dropped, or detonated in the sea or ocean or above the ocean waters. There have been tests done in various parts of the world. This was done with nuclear bombs in the area of the Bikini Atoll and resulted in tsunami. A top secret New Zealand program to experiment with tsunami caused by explosions was known as Project Seal, in the 1940's.

Size

This wave is massive - nothing like what a surfer seeks. The waves can be as high as 100 ft. tall when they near shore. They initially will create a series of waves deep in the ocean, that are only a few feet tall. They cannot be clearly discerned from shore or ships until they get to the shallows close to shore and then can be identified too late to allow warning and people to escape.

The largest recorded tsunami was in Lituna Bay Alaska at 1720 feet (524.25600 meters).

Speed

Tsunamis move faster than a human being on shore and can not be "outrun". These waves can travel under water at great speeds, up to hundreds of mph. They can travel as shallow waves at 500 mph deep under the sea. Close to the shore, this speed reduces to 30 to 40 mph. Although the momentum slows upon reaching land, it still hits with a major force.

How the waves move

The waves travel in all directions from the area of disturbance, much like the ripples that happen after throwing a rock into water.

The crests of the tsunami waves can be as much as a hundred miles apart. They can cross the entire ocean in less than a day without losing much energy. Tsunami waves can be as long as 60 miles and be as far as an hour and 100 miles apart. They destroy vast cities and developments on land, but at the same time don't destroy ships as they travel beneath them on the way to shore. They can pass right under the ships unnoticed. That's because the height of a tsunami wave might be only a foot or two at those depths. Or they might be noticed but not given any special attention because they seem harmless as they travel under the ocean surface.

The situation changes dramatically when the waves come closer to shore. As they enter shallow waters, they begin to decelerate and gain height as the wave becomes compressed and the seafloor rises in height.

Tsunami travel through water, and therefore can reach areas not located near the epicenter of the earthquake. Reflection and diffraction can change the regions affected. This was seen in the 2004 Boxing Day tsunami, whereby the wave front diffracted around the tip of India and Shri Lanka and hit the western coast of India, a section of coastline that was not in the direct line of the tsunami.

This wall of water travels underwater until it reaches the shore. Once a tsunami reaches the shallow water near the coast, it slows down. The top of the wave moves faster than the bottom, causing the sea to rise dramatically. It will uplift and form the huge wave and as the water gets more and more shallow, it rises and rises until it is at its maximum height.

Interestingly, a tsunami will cause the water along the shore to pull away from shore into the oncoming tsunami, adding more and more water to the "big wave" on its way in. This displacement pulls water back from the shore, causing the wave to build in size and intensity. Depending on whether the leading element of the tsunami is a trough or a crest (it can be either) there may be an eerie ebbing or pulling back of the water along the shore; it must appear to observers like an unnatural pulling back of the tide. This would happen if the leading element is a trough.

Many people get so mesmerized by the unusual sights at the shoreline that they don't recognize the impending danger. Tsunami kill a lot of people because of the fierce strength of the initial wave, subsequent waves, and the undertow created by gallons of rushing water.

Storm Surge vs Tsunami

Tsunami are not caused by storms or wind or other weather phenomena. Those would be storm surges which are different waves.

Some meteorological storm conditions, such as deep weather depressions that cause cyclones, hurricanes, strong winds and other similar occurrences, can generate a storm surge, which can be several meters above normal tide levels. This is due to the low atmospheric pressure within the center of the weather depression. As these storm surges come ashore, the surge can resemble a tsunami, inundating vast areas of land. But they are not one and the same.

Results and devastation of tsunami

As we have seen from the 2004 tsunami of Southeast Asia and the 2011 Japanese tsunami, the effects can be devastating. A tsunami has great energy, and can carry waves far inland. The power of the water can knock down buildings and crush vehicles. People usually die from being smashed against something, rather than drowning. Tsunami can push huge amounts of water over islands and coastal regions causing the deaths of hundreds of thousands or millions of people, and they can cause millions or even billions of dollars worth of damage.

They can move up the rivers and streams leading to the ocean. Flooding can reach land 1000 feet (300 meters) from the coastline and the dangerous waves have enough force to lift giant boulders, flip vehicles, and demolish houses. Tsunami kill a lot of people because of the fierce strength of the initial wave, subsequent waves, and the undertow created by gallons of rushing water.

Tsunami will definitely cause damage, casualties, and injuries. Fires can break out from gas line breaks that are ignited. Tsunami, as they reach closer to shore, will wash fishing boats and other boats, such as cruisers, onto shore, and onto streets, railroads, and buildings. Airports are destroyed, roads are impassable. The boats will be stuck on shore and usually wrecked from the force of the wave. Cars, trucks, airplanes and trains can be washed through the coastal areas damaging structures and people in their wake.

Entire coral reefs and the plants and animals that depend on them for habitat can be devastated. Once the reefs are destroyed, the protection they provided for the coastal areas from hurricanes, storms and other damage is lost along with the barrier reefs.

People and livestock can be caught in the wave and carried away inland and back into the sea with all the debris from the devastation. The waves will also cause fish to be washed onto the shore and stuck there to die. They flood the lands near the shore, causing entire buildings to be inundated. They are identified too late for most people in the coastal areas to escape and avoid death from them. They will damage the crops and cause nearby buildings to collapse. Some people might be trapped under the buildings and die. They uproot trees too, causing them to fall on houses and people.

Lastly, they cause economic decline as countries have to spend billions of dollars rebuilding and recovering from the damage. Millions of people can be homeless without food, clean water, and proper sewage disposal and without electricity. Hospitals that may be still operating are overwhelmed, injured people may not receive timely medical care. Access to medical supplies, pharmacy supplies, and maintenance medications may not be available for months or more. People cannot find loved ones and family members and there are little, if any, means of communication immediately following the tsunami. Factories and jobs are eliminated and many never rebuild in the area again. Tourist industries collapse for even years afterward.

Tsunami "Season" ?

There is no tsunami season, they are unrelated to weather, so they can occur at any time just like the things that cause them can happen any time of year… plate subduction, earthquake, volcano, etc.

Tsunamis can take place at any time; night or day.

Where they occur

Tsunami could occur anyplace there is a large body of water (even large lakes). They can move up the rivers and streams that connect with the body of water of the tsunami, causing further destruction and flooding.

They often hit along the coasts of the "Ring of Fire," around the margins of the Pacific Ocean. In the US: California, Washington, Oregon, and Hawaii and the Japanese coastlines are all potential areas where denser oceanic plates slip under continental plates in the process mentioned above known as tectonic plate subduction. One in Chile sent tsunami warnings ino the pacific. Thailand is in a circle where tsunami hit a lot. There is a well known spot in Alaska where a Mega Tsunami hit, Lituna Bay. There was the tsunami in the Bay of Bengal in 2004.

There was one on October 7, 2009 , originating from an underwater earthquake near the Vanuatu Islands in the southwest Pacific. The wave affected other islands, including Hawaii and Fiji, as well as Alaska and California. This tsunami, however, was weak and insubstantial compared to a devastating tsunami on December 26, 2004, also known as the Sumatra-Andaman earthquake. The wave itself was up to 100 feet (30 meters) high in places. At the time it was considered the fifth worst natural disaster in recorded history, and the deadliest tsunami ever, possibly more than four times worse than the next deadliest tsunami (in terms of death toll, rough estimates range from 229,866 to 443,929 people killed).

Mega Tsunami

Mega earthquakes (measuring 9.0 and above on the Richter Scale) are said to produce Megatsunami (also known as Iminami) which are much more destructive than normal tsunami. They can reach heights of up to 300-500+ meters, and reach about 25 km inland. They are said to be able to cross the Atlantic (Transatlantic).

As mentioned above, an example of a mega-tsunami happened on the 9th of July in 1958 in Lituna Bay in Alaska, generating the largest recorded tsunami. An earthquake measuring 7.7 on the Richter scale caused 90 million tons of rock to fall directly into the sea. It caused a wave 524 meters high (1720 feet).

The wave from the collision of the KT Event 65 million years ago (an asteroid) is believed to have been up to 1.5 kilometers high.

When Cumbre Vieja in La Palma eventually collapses into the Atlantic it could generate a 2000 foot high wave rushing across the Atlantic at 500 mph.

Predictions, warnings, and animal behavior

Scientists are not yet able to predict them just as volcano eruptions and earthquakes can't be predicted. Seismic activity could signal a warning, however, and this is under study.

Animals often recognize the danger and run inland. One explanation of this is that animals can sense the movement of the air and hear changes in the waves much faster than humans recognize these.

531532533
Tsunamis

Do tsunamis have weather geologic or humans cause?

Tsunamis are geologic in origin. Typically they are triggered by earthquakes, but other causes can include landslides and volcanic eruptions.

477478479
Tsunamis

Who to call first on tsunami?

Txunamy from family diamond

301302303
Earthquakes
Tsunamis

Can lightning cause earthquakes?

No

There are two main causes of earthquakes.

Firstly, they can be linked to explosive volcanic eruptions; they are in fact very common in areas of volcanic activity where they either proceed or accompany eruptions.

Secondly, they can be triggered by Tectonic activity associated with plate margins and faults. The majority of earthquakes world wide are of this type.

299300301
Hurricanes Typhoons and Cyclones
Belize
Tsunamis

Does Belize have hurricanes tsunami and floods?

Belize is too close to the equator to be at a significant risk for hurricanes. The majority of the country is at fairly low elevations and is in a geologically active area, so the probability of tsunami is fairly high in coastal regions, and the low inland elevations and high rainfall make inland flooding likely.

267268269
Haiti
Earthquakes
Tsunamis

How many aftershock are normal after an earthquake?

there are lots but we feel about 5 of them it depends how big the quake adtually is

261262263
Coastlines
Tsunamis
Natural Disasters

How do tsunamis happen?

A tsunami (Japanese for harbor wave) can be caused when a large volume of water in a sea or ocean is displaced. Tsunamis can happen most anywhere that there is an ocean or giant body of water. They especially happen where major natural events like underwater earthquakes or volcanoes can happen.

A tsunami can be generated when convergent or destructive plate boundaries abruptly move and vertically displace the overlying water. There is usually a movement underwater, like an earthquake, where the earth's plates push together, or a landslide, which causes a wave to be generated. When tectonic plates slide on each other, that's when an earthquake may happen. Because they can slide under the ocean, the impact can make the water form a giant wave. This wave is massive - nothing like what a surfer seeks. The wave can be meters high, and as it rushes closer to the coast it gains enough momentum to wreak massive damage on land. The momentum slows upon reaching land, but it is still a major force.

Get in a pool or the bath tub and put your hand a good ways down and then pull it up quickly but not out of the water, pull up strong but don't break the surface and watch the result. Not exactly a tsunami, but a simple version of the science.

Tsunamis can be caused from different kinds of events, including, but not limited to:

Sea bed earthquake, displacing water (the most likely cause).Distance landslides into the ocean or sea.Tropical storms or hurricanes.Volcanic disruption.Meteor striking the ocean or sea. More details

Most tsunamis occur when there are underwater seismic events such as an underwater earthquake or volcanic eruption. This normally occurs along plate boundaries. Subduction in convergent boundaries account for most tsunamis. This will cause shock waves to be radiated out of the epicenter. There will be a rise or fall of the seabed. This displacement will create a wave which cannot be clearly detected from shore. These waves can travel at speeds up to 700 mph (i.e. the speed of sound in water). As the wave gets nearer to the shore, the wave will compress and gain height in the shallower water. The waves can be up to 100 ft. (30 m) or more when they come ashore.

Tsunamis can also occur because of landslides. When land subsides into water bodies (usually extremely large landslides), they can create a wave that resembles a tsunami. The wave of these kinds of tsunamis will not be very high, unless a huge volume of rock or ice is involved.

Tsunamis can also occur when asteroids fall into the water bodies. This is extremely rare, and they must be extremely large to cause a large water displacement to form a wave. Meteorites will not cause high waves as they are usually much smaller than asteroids.

Some meteorological storm conditions such as deep depressions causing cyclones, hurricanes, strong winds and other similar occurrences can generate a storm surge, which can be several metres above normal tide levels. This is due to the low atmospheric pressure within the centre of the depression. As a storm surge comes ashore, it can resemble a tsunami, inundating vast areas of land.

261262263
Hurricanes Typhoons and Cyclones
Tsunamis
Similarities Between

What is the different between a cyclone typhoon tsunami?

A tsunami is a wave resultant from a storm. However, cyclones and typhoons are very similar with cyclones occurring in the western hemisphere and typhoons in the eastern. The major difference is that the eye of a cyclone is round, whereas the eye of a typhoon is slanted.

251252253
Tsunamis

When did the Asian tsunami hit India?

because their call centres insist on ringing at dinner time! just kidding no idea

251252253
Tsunamis
Conditions and Diseases
Avalanches

Can bursitis be prevented?

Over exercising or the repetition of a movement that triggers the condition should be avoided.

211212213
Japan
Tsunamis
Earthquake in Japan 2011

How did the victims in japan get emergency aid after tsunami and earthquake?

someone with acess to a phone and who was not dead would have rung emergency aids. there would have been a lot of people doing this and once the aids got there they would have called backup. :)

209210211
Tsunamis

What was the biggest tsunami ever recorded?

This depends on what is meant by "biggest".

Largest/highest tsunamiThe largest tsunami ever recorded occurred on 9 July 1958 in Lituya Bay, Alaska. An earthquake measuring 8.3 on the Richter scale shook loose around 40 million cubic yards of dirt and glacier from a mountainside at the head of the Bay, resulting in a tsunami, or series of waves. Although the only witnesses to the event were a couple of fishing boats, the height was able to be determined by scientists finding the high water mark, where the water reached its highest point on the nearby land. This massive tsunami reached a height of 524 metres, or over half a kilometre, the equivalent of 1,720 feet or 40 feet short of a third of a mile. This is twice the size of the Eiffel Tower.

Although the hillsides in the bay were devastated, the damage was very localised and minimal, as Lituya Bay is very remote, there were very few casualties. The Lituya Bay tsunami was labeled a mega-tsunami, but its damage was relatively small because the area is so remote. It was fortunate that the area was uninhabited, or else the effects could have been even more devastating. As it was, two people died when their fishing boat sank when it was hit by the tsunami.

Higher tsunamis are believed to have occurred without human witnesses, so their heights have not been recorded.

Most devastating tsunamiNot the largest, but the most devastating tsunami ever recorded was the Boxing Day 2004 tsunami. The Sumatra-Andaman earthquake on 26 December 2004 resulted in an earthquake with the magnitude of 9.3 occurring on the ocean floor near the west coast of Sumatra, perhaps the most devastating tsunami ever recorded, the height of the wave was only about 100 feet, far from the largest. Over 230,000 people were killed. The impact of this earthquake affected the time of the Earth's rotation time and It caused the entire planet to vibrate as much as 1 cm (0.4 inches).
195196197
Earthquakes
Plate Tectonics
Tsunamis

Why do the largest earthquakes not always cause the most deaths and damage?

Large earthquakes often occur far from the most densely populated regions of the Earth. But they can still kill many people. When even a moderate quake hits a developed, populated area (such as San Francisco or Japan), the damage can be more more severe.

Probably the single biggest reason why the 2011 Japan quake caused less deaths than the much smaller, weaker 2010 Haiti quake would be the stringent building codes in Japan, versus Haiti which had no real building codes. Japan is a very technological, safety and quality-focused nation. Japan has a long history facing calamity from earthquakes and tsunami, going back centuries, and tragedies of the past has taught the Japanese government and people to always be prepared. They make their buildings to withstand earthquakes, and build great seawalls to protect against the horrors of tsunami. Tragically during the 2011 earthquake, the tsunami that struck was bigger than the walls had been designed for. Fortunately the Japanese government and culture is focused on safety and discipline, and from an early age, the Japanese are taught what to do when an earthquake strikes, to get to safe places if a tsunami is likely. The death toll is still horrific and devastating and not to be diminished, but many people were saved by the combination of the tsunami warning system and the education that Japanese people receive to heed tsunami warning sirens and get to higher ground.

Most places along the United States' west coast are prepared for moderate to large earthquakes, though not for earthquakes as strong as Japan's. A Haiti-sized earthquake striking Seattle or Los Angeles would likely not cause anywhere near the loss of life and infrastructure damage that it did in Haiti. However, because earthquakes are rare, cities and states in the United States farther inland and on the east coast are not prepared. New York only adopted its first earthquake building code in 1995, and it was only stipulated to make new buildings able to withstand an earthquake about one-tenth the intensity of the Haitian quake. No older buildings are required to be retrofitted, which means most of New York City's skyskrapers would be vulnerable and a Haiti-sized earthquake striking New York City would likely cause much more catastrophic death tolls than were it to strike cities on the West Coast where building codes are stronger.

175176177
Hurricanes Typhoons and Cyclones
Tsunamis

How are tsunamis and hurricanes different?

A tsunami is a large wave or series of waves usually triggered by an underwater earthquake or landslide. Tsunamis arise from geologic forces and are not weather-related.

A hurricane is a very large and powerful storm that forms over warm ocean water. More specifically a hurricane is a tropical cyclone with sustained winds of 74 mph (119 km/h) or greater.

193194195
Tsunamis

What time of year do tsunamis happen most?

Tsunamis are not dependent on the time of year. They can happen at any time.

190191192
Singapore
Tsunamis
Natural Disasters

What would happen if a tsunami flooded Singapore?

Singapore would get flooded utterly and nearly the entire island would be submerged underwater, along with large loss of life.

181182183
Tsunamis

What is the most tsunami prone country?

It would have to be Japan because they have major earthquakes and tsunamis every few years. Then next in line would be Chile.

173174175
Tsunamis

Do tsunami have weather or geologic or humans cause?

Tsunamis are the result of geologic processes.

161162163
Thunderstorms and Lightning
Tsunamis
Blue Whales

How big was the largest tsunami ever recorded?

The tallest tsunami ever recorded was at Lituya Bay, Alaska. July 7th, 1958, 1638 foot tall waves that were caused by a huge ice/rock fall. This is twice the size of the Eiffel Tower.

Further details: The highest naturally-occurring tsunami ever recorded occurred in Lituya Bay, a large inlet on the coast of Alaska. It is believed that an earthquake of either 7.9 or 8.3 on the Richter Scale, occurred along a nearby faultline, part of the Pacific Rim of Fire. Around 40 million cubic yards of dirt and glacier were shaken loose from a mountainside at the head of the Bay, resulting in a tsunami (series of waves), the highest of which reached over 500 metres. Although the only witnesses to the event were a couple of fishing boats, the height was able to be determined by scientists finding the high water mark, where the water reached its highest point on the nearby land.

It was fortunate that the area was uninhabited, or else the effects could have been even more devastating. Higher tsunamis are believed to have occurred without human witnesses, so their heights have not been recorded.

151152153
Tsunamis

What is the difference between tsunamis and seiche?

Tsunami (soo-NAH-mee): a Japanese word that means harbor wave; a sea wave of local or distant origin that results from large-scale seafloor displacements associated with large earthquakes, major submarine slides, or exploding volcanic islands. Typically generated by seismic or volcanic activity or by underwater landslides, a tsunami consists of a series of high-energy waves that radiate outward like pond ripples from the area in which the generating event occurred.

And A

Seiche (saysh): a series of standing waves (sloshing action) of an enclosed body or partially enclosed body of water caused by earthquake shaking. Seiche action can affect harbors, bays, lakes, rivers, and canals.

155156157
Tsunamis

Why do tsunamis hit certain places more?

tsunami"s are like hurricanes and it comes up into the air and goes to certain places.

153154155
Tsunamis

How is a tsunami formed?

A tsunami is a Japanese word for "big wave". A tsunami is kind-of like a hurricane but not that severe and it only last for some minutes, unlike a hurricane which could last for hours or so.

A tsunami will take place ONLY in warm waters. Tsunamis can hit along the coast of the ring of fire. California, Washington. Oregon, Hawaii, and the Japan coastline are all potential areas.

The Tsunami is only about 1 metre high when it is deep waters, but when it get more shallow the waves get slower and bigger.

A tsunami wave it would depend on the size of the earthquake to tell how big the tsunami's size.

Tsunamis are known to kill lives, destroy homes, and ravage countries. If you are ever in a tsunami, it is like a HUGE wall of water slamming into you over and over again. Tsunamis kill a lot of people whether they not know how to swim, or not, because of the fierce strength of the initial wave, subsequent waves, and the undertow created by gallons of rushing water.

Tsunamis occur when there is a sudden large displacement of water. There are three main causes of tsunamis:

1.Seismic activity

2.Submarine landslides

3.Cosmic Impacts

The first way is caused by a mega thrust earthquake. An example of this is the tsunami of Boxing Day 2004. Mega trust earthquakes occur when techtonic plate boundries suffer a large veritcal displacement. The upward movement of the land causes a large displacement of the water causing the wave. Seismic waves carry the water's waves out of the water to the surface. The displacement pulls water back from the shore, causing a large major wave to build in size and intensity. (Displacement would be similar to dropping a marble into a glass of water while tilting the glass to one side.)

The second way is called a Mega Tsunami (which can be much larger than a normal tsunami) is caused by a landslide or meteor impact into the sea. An example of this happened on the 9th July 1958 in Lituna Bay in Alaska. A earthquake measuring 7.7 on the Richter scale caused 90 million tonnes of rock to fall directly into the sea. It caused a wave 524 meters high.

Tsunamis are formed if there is a very big earthquake or earth tremers that shake the earth to at least 6.0 on the Richter scale.

The third way is more rare: a cosmic impact from a meteor. The result is mostly the same.

Interestingly, a tsunami will cause the water along the shore to pull away, adding more and more water to the "big wave". Many people get so mesmerized by the unusual sights at the shoreline that they don't recognize the impending danger.

Also of interest, animals often recognize the danger and run inland. The theory for this is that animals can sense the movement of the ear and hear changes in the waves much faster than humans recognize these.

145146147
Tsunamis

What is a tsunami?

The word tsunami (pronounced su-nah'-me) is Japanese for harbor wave. Some tsunami may reach heights of 100 feet (30 m) or more. They are giant waves that hit a coastal area and create destruction and usually loss of many lives.

A tsunami can be caused by a coastal or underwater earthquake, an underwater or shoreline landslide, an undersea volcano, the explosion of a volcano near shore, or even by an asteroid or other large celestial body that might crash into the ocean. Sometimes a small underwater quake will trigger a landslide that causes a tsunami.

Such waves are also (incorrectly) called tidal waves because they inundate like high tides. But they aren't true tidal waves and are not related to tides or the effects of the moon.

They can travel at 500 mph deep under the sea. They can destroy vast cities and developments on land, but don't destroy ships on the way to shore. Since they are traveling deep in the sea, they can pass right under the ships unnoticed. That's because the height of a tsunami wave might be only a foot or two at those depths. Or they might be noticed but not given any special attention because they seem harmless as they travel under the ocean surface.

But the situation changes dramatically when the waves come closer to shore. As they enter shallow waters, they begin to decelerate and gain height as the wave becomes compressed. Waves up to 100 feet (30 m) or more in height are possible. Of course, one caused by an asteroid impact could be much higher, depending on the asteroid's size. Fortunately such occurrences don't happen as frequently as those caused by earthquakes, volcanoes and underwater landslides.

More Detailed Information:

Tsunami are huge ocean waves caused by natural forces like underwater earthquakes. Tsunami are caused when the forces of these phenomena rapidly displace large amounts of water.

Most tsunami occur when there is an earthquake or volcanic eruption in the sea or ocean. This is caused when there are plate boundaries that are meeting in plate tectonics processes. Subduction in the convergent boundaries accounts for most of the tsunami. This will cause shock waves to be radiated out of the epicenter. This natural event will cause a rise or fall of the seabed. This will create a wave deep in the ocean which cannot be clearly discerned from shore until they get too close to allow escape.

These waves can travel at great speeds up to hundreds of mph! As the wave gets nearer to the shore, the wave will start to get higher as the seafloor rises in height. The waves can be as high as 100 ft. tall when they near shore.

Tsunami can be caused by landslides when there are very large landslides, such as a cliff-side of a mountain near shore that falls into a large body of water or ocean.

Tsunami can also occur when powerful bombs, like nuclear bombs, are tested, dropped, or detonated in the sea or ocean. These will also cause shock waves to be radiated out that move the ocean waters in waves as described above.

Tsunami can also occur when large asteroids fall into the water. This is extremely rare, and the asteroids must be extremely large to cause a large water displacement to form a wave. But they are known to have occurred. Meteorites will not cause high waves as they are usually much smaller than asteroids by the time they have been burned in the atmosphere on the way to the surface.

Some meteorological storm conditions, such as deep weather depressions causing cyclones, hurricanes, strong winds and other similar occurrences, can generate a storm surge,which can be several meters above normal tide levels. This is due to the low atmospheric pressure within the center of the weather depression. As these storm surges come ashore, the surge can resemble a tsunami, inundating vast areas of land. However, these are not tsunami, but storm surges.

Tsunami will definitely cause damage, casualties, and injuries. Fires can break out from gas line breaks that are ignited. Tsunami, as they reach closer to shore, will wash fishing boats and other boats, such as cruisers, onto shore, and onto streets, railroads, and buildings. Airports are destroyed, roads are impassable. The boats will be stuck on shore and usually wrecked from the force of the wave. Cars, trucks, airplanes and trains can be washed through the coastal areas damaging structures and people in their wake.

People and livestock can be caught in the wave and carried away inland and back into the sea with all the debris from the devastation. The waves will also cause fish to be washed onto the shore and stuck there to die. They flood the lands near the shore, causing entire buildings to be inundated. They are identified too late for most people in the coastal areas to escape and avoid death from them. They will damage the crops and cause nearby buildings to collapse. Some people might be trapped under the buildings and die. They uproot trees too, causing them to fall on houses and people.

Lastly, they cause economic decline as countries have to spend billions of dollars rebuilding and recovering from the damage. Millions of people can be homeless without food, clean water, proper sewage disposal and without electricity. Hospitals that may be still operating are overwhelmed, injured people may not receive timely medical care. Access to medical supplies, pharmacy supplies, and maintenance medications may not be available for months or more. People can not find loved ones and family members and there are little, if any, means of communication immediately following the tsunami. Factories and jobs are eliminated and many never rebuild in the area again. Tourist industries collapse for even years afterward.

See related questions for more detail


a tsunami is a giant flood

144145146
Japan
Tsunamis
Earthquake in Japan 2011

What does the mantle have to do with the 2011 tsunami in Japan?

The mantle has everything to do with this earthquake, without the convection currents in the mantle the plates would have not moved to cause the earthquake in the first place. The problem is that Japan is at a destructive (also called compressional) plate boundry, not just that but there is another four plate boundaries quite close by to magnify the effect of the earthquake, the movement of the crust could also mean that there could be magma rising through the crust ready for an eruption. The earthquake caused the ocean crust to move 10m which displaced the water to create the tsunami.

127128129
Tsunamis

Is a tsunami going to happen?

Yes, though when, there is no way of knowing. Try contacting local weather experts for more info, though it is inevitable that a tsunami will happen some time somewhere. One may be even going on right now as I type this, and as you read this answer.

131132133

Copyright © 2020 Multiply Media, LLC. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.