Tsunamis: Nature’s Misunderstood natural disasterPhysics 1010 – Section 010

Megan Cluff, Dan Mace, Aaron Dodds, and Sam Adams

Abstract

The following summarizes tsunamis with the aid of various articles, books, reviews, and personal

accounts. This report outlines the basic physics of tsunamis and the history behind them.

Information is included on the commercial aspects, future preparations, precautions, and

procedures being put into place to better equip tsunami prone areas. The report will inform

people of the complete and global effects of tsunamis and educate individuals on their past and

future relevance.

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Introduction to Tsunamis

The following synopsis is an eyewitness account of the 2004 Indonesian tsunami from writer

Rick Von Feldt. Von Feldt is among one of the authors of Surviving the Tsunami- First Hour.

The trip to Patong Beach is about 30-45 minutes. Since it was early there was little

traffic, and so we made good time. As we drove along the beach, I looked to my right as

we slowly went along. I noticed two things. First, people were standing up. There were

hundreds of beach chairs where people were standing. I cranked my neck to see what

they were watching. A whale? Nah, not here in the Indian Ocean. Dolphins? Possible, but

odd. What were they all looking at?

Secondly, I noticed that there was…well…no water. I remembered thinking,

"Was the tide pool that strong the last time I was here?”. We came to the end of the

beach. The vehicle climbed the steep road up the side of the hill wrapping around the bay.

The hotel is positioned high up from the beach but overlooks the entire bay. Upon arrival

I noticed that all of the staff of the hotel was crowding at the edge looking over the bay. I

walked to the edge to see what they were watching. I asked one of them, "What are you

looking at?” Staff members responded “Water! The water!". They also noticed that all of

the water had gone away. Boats were suddenly grounded, and people dotted the beach in

perplexity.

Suddenly in front of our eyes the bay began to fill! The bay filled rapidly as if

someone had turned on giant faucets. The water seemed to rush in. In about 10-15

minutes the bay filled entirely. Within minutes we saw the swell. It was perplexing, the

day was nice and sunny and we could not figure out or believe what was happening. The

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swell came and we saw it rush over the wall. The water kept rising. It went higher than

the palm trees along the edge. Local people began to cry for they knew what the water

meant.

The water receded slightly and

then with a vengeance it rushed

forward. The 18 foot wall rolled over

the front of local shops and everything

in its path. We stood there in disbelief

realizing that one of the most awful

things that could happen did. We could

see people in hotels climbing up as

quickly as possible. They huddled on

the roofs of all the hotels. Down below we could see boats, automobiles, and smaller

objects being thrashed against the buildings. It looked like a bathtub with lots of small

toys…surreal…but real enough. For four hours the water kept this up, battering the sea

front. Yes, the sun kept shining…a very deceptive paradise.

As portrayed in figure 1.1, tsunamis have the power to destroy large amounts of

structures. In the account of a simple business trip, Von Feldt effectively captures the shock and

awe of a natural disaster in progress. By creating a sense of personification about the wave, the

author takes control of the memory. The memory leaves a reader incapable of shutting the

images out of his or her mind. It is almost as if Von Feldt had created his own Frankenstein, the

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alarming monster that no one can understand. To the contrary, tsunamis (although unpredictable)

are well understood by many.

Background Information

Generally speaking, the physics behind a tsunami are quite simple. These natural

disasters demonstrate the understanding of many basic principles of physics. Most notably

tsunamis display the laws of conservation, how energy from one thing is carried on to another,

and the basic idea of displacement. These concepts will now be highlighted.

Let’s first consider how a tsunami is generated. Most frequently tsunami waves are

triggered by varying factors. Tectonic movements along the ocean floor, underwater volcanic

eruptions, landslides above the surface of the water, or large objects crashing into the ocean are

among some of theses factors. These factors all have a force behind them. Recall that the force of

an object is determined by its mass multiplied by its acceleration. The force of the moving earth

in any of these scenarios is extremely powerful which begins the creation of a tsunami.

With the movement of a mass this size, one must consider where the water surrounding it

will go. It does not disappear nor absorb into the mass itself. The water in fact becomes

displaced, or it surrounds the mass and takes its place (Stevenson 2005). For example, in the case

of an underwater earthquake, the tectonic movement of one plate downward will cause the water

directly above it to takes it place. At the same time, upward movement of a neighboring plate

will cause the earth to take the place of the water. The water is then pushed upwards creating a

swell that forms the tsunami. From here, the energy of the movement is transferred from the

earth to the water.

Gravity is the underlying force that starts the movement of a tsunami. This force pulls

downward which helps disperse the transferred energy horizontally through the water. These

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actions create a vertical column of horizontal energy (Stevenson 2005). It is important to note

this because the horizontal movement of the energy combined with gravity triggers the

movement of a tsunami from it’s origin to the ocean shore.

Horizontal movement of a tsunami explains why these natural disasters are hard to see in

the open ocean. Typically a tsunami wave away from the shore is no more than three feet high.

This is certainly nothing observers would think of causing harm. However size is not the only

difference between an ordinary wave and a tsunami wave. Tsunami waves move much quicker,

between 500 to 600 miles per hour to be exact (Stevenson 2005). The depth of the ocean floor at

the point of origin is what determines these speeds. Although the length between waves range

from 60 to 300 miles apart from one another, the physical speed of these waves are highly

dangerous (Stevenson 2005).

When gravity acts on an object, the object is pulled downward and picks up speed as it

travels. It is no different for the amount of energy within a tsunami. The deeper the ocean is, the

longer gravity can act on it and the

faster it will fall. These actions

keep the energy in motion. From

here it continually transfers the

energy through the water at an

increasing pace. As the energy

moves, the depth of the ocean

changes forcing the wave upwards towards the shore, as shown in figure 1.2. Rather than

dispersing the energy begins to compress, slowing the speed to around 30 miles per hour as it

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Figure 1.2 illustrates the basic parts included in the forming of a tsunami near a coastline.

travels upward. This forces the water into a vertical column that can reach up to an astonishing

100 feet.

Before the wave strikes, it is typical to see the water on the beach receding, as described

in Von Feldt’s account, followed by the trough of the oncoming wave. Unlike most depictions,

several tsunami waves can strike over a matter of hours depending on the force of the original

displacement of land.

The History of Tsunamis

Although many individuals do not live near an ocean, all of society has been exposed to

the recent media coverage of the March 2011 tsunami in Japan. Americans associate the word

“tsunami” with a giant wave or wall of water, but the term happens to be relatively new to the

English language. In fact, the word tsunami is Japanese and directly translates as “’harbor wave”

(Simmons-Duffin 2011). It wasn’t until the 1896 tsunami striking the main island of Japan that

National Geographic reported a great earthquake wave. Sources explained that the Japanese

referred to it as a tsunami which introduced the term to English speakers. This began the word’s

popularity throughout the media.

The fact that the word tsunami is Japanese is fitting. Nearly one third of all recorded

tsunamis have occurred in Japan (Simmons-Duffin 2011). The country has experienced a

tremendous amount of destruction and loss of life at the hands of earthquakes and corresponding

tsunamis. This is due to the location of Japan in relation to tectonic plates. The shifting of these

plates are a primary reason for these natural disasters to occur.

Although there are no physical written documents of all recorded tsunamis, geological

history has shown researchers that there has been multiple tsunami disasters overtime. According

to officials of MSNBC, “A volcano avalanche in Sicily 8,000 years ago triggered a devastating

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tsunami taller than a 10-story building that spread across the entire Mediterranean Sea, slamming

into the shores of three continents in only a few hours” (Than 2006). While there are no written

records of the devastation this event caused, MSNBC writes:

The Mt. Etna avalanche sent 6 cubic miles of rock and sediment tumbling into the water

—enough material to cover the entire island of Manhattan in a layer of debris thicker than

the Empire State Building. The mountain of rubble crashed into the water at more than

200 mph. It pummeled the sea bed, transformed thick layers of soft marine sediment into

jelly and triggered an underwater mudslide that flowed for hundreds of miles.

The amount of destruction is hard to comprehend to the general public. Scientists

however can observe the different sedimentary levels within the region. This evidence shows that

the natural disaster in Sicily greatly disrupted the lives of those living in the area. This is seen

through an excavation of a Neolithic village located in present-day Israel. Archeologists found

evidence of a sudden disappearance of the people, including a meal of fish being left to rot.

One of the first recorded tsunamis took place on November 1, 1755. The tsunami

followed a massive earthquake that shook Portugal and other parts of Europe. According to

authors Charles D. James and Jan T. Kozak, “many people of the city of Lisbon sought safety in

boats following the intense earthquake. Roughly thirty minutes later these residents were struck

by three waves”. The tsunamis capsized boats, dragged people and debris from the shores into

the ocean, and altered the shorelines of Morocco, Ireland, and Barbados. The earthquake not only

caused tsunamis, but ultimately led to outbreaks of massive fires and destruction. It is estimated

that the event claimed more than 60,000 lives (James and Kozak 1998). James and Kozak further

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explain that the event had a profound and lasting effect on the region, which was later depicted in

multiple forms of artwork.

One of the most infamous tsunamis was caused by the greatest volcanic eruption in

recorded history: the eruption of Krakatoa. The event was heard 3,000 miles away. Explosions

threw five cubic miles of earth 50 miles into the air, creating 120-foot tsunamis and killing

36,000 people. Of those deaths, 31,000 are attributed to the tsunamis alone (Phillips 2011). The

force of the volcanic eruption was so intense that it blew two thirds of the island into the water.

Although the island of Krakatoa was not inhabited, the resulting tsunami swept through the

shores of the neighboring Sumatra and Java islands. The waves devastated the inhabitants of

these islands, claiming multiple lives and wiping out much of the land’s vegetation (Livescience

2004).

In relation to Feldt’s story, the most deadly tsunami in history took place on December

26th, 2004 off the shores of Indonesia. According to National Geographic, the tsunami was

caused by the overlapping of two tectonic plates (the India plate and the Burma plate), which led

to a massive 9.0 magnitude earthquake. National Geographic News explains in their article that

the earthquake “is estimated to have released the energy of 23,000 Hiroshima-type atomic

bombs.” This energy shifted the ocean floor which triggered deadly tsunamis. The tsunamis

traveled at speeds close to that of a jetliner. The tsunamis devastated communities in various

countries including Thailand and Africa. Researchers explain that reason there was little warning

was due to the small size of the wave within the body of water (National Geographic News

2005).

When a tsunami reaches low water near the coast it tends to slow down. The top of the

wave moves faster than the bottom, causing the sea to rise severely. In this example, the people

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on the shorelines were unprepared as tsunamis are so rare in the area. As the shorelines retreated

before the arrival of the tsunami, people were drawn to the beaches in order to see the newly

exposed areas of the seafloor and the beached sea life. The few that were able to recognize the

threat ran for higher ground and encouraged others to do the same. By the time the tsunami hit,

there was little chance of outrunning the fast-moving wall of water, being around 50 feet high.

Animals living in the area were able to sense the huge tidal waves coming long before

their human counterparts. The animals also seemed to know that the “disaster was imminent.

Many people reported that they saw animals fleeing for high ground minutes before the tsunami

arrived. Very few animal bodies were found afterwards” (National Geographic News 2005).

Around 150,000 bodies were found dead immediately following the event, but the death toll

would rise to around 230,000 after inadequate aid was given to the injured survivors, and disease

ran rampant in areas that were demolished by the tsunami (National Geographic News 2005).

The most recent catastrophic tsunami took place on March 11 of this year. The waves

were triggered by a 9.0 magnitude earthquake, the largest in Japanese history, off the shores of

northeastern Japan. According to the BBC, “Strong waves hit Japan's Miyagi and Fukushima

prefectures, damaging dozens of coastal communities. A 10 meter wave struck Sendai, deluging

farmland and sweeping cars across the airport's runway. Fires broke out in the centre of the city”

(Buerk 2011). The immense destruction caused by the natural disaster was televised around the

world. News agencies showed entire communities being washed away by the water. Cars and

homes had become debris in the chaotic rush that ravished much of Japan’s shoreline. After the

event thousands were found dead, and even more were missing in the area. Japan struggled to

account for the lost individuals while trying to avoid a meltdown at the Fukushima nuclear

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power plant, which was heavily damaged by the earthquake. Currently there is no exact death

toll. Much of the coastal region is abandoned and remains in ruins to this day (Buerk 2011).

Commercial Application

While the effects of tsunamis are upsetting and global on the physical scale, they are also

substantial and monumental on the commercial side. There are countless homes, businesses,

properties, automobiles and endless amounts of priceless objects that are destroyed based on the

sudden strike of a tsunami. These possessions usually have value and insurance costs. The price

tag on damages around the world can reach in the billions. Not only do the commercial locations

of the tsunami reap a damaging harvest, but foreign markets are also affected. Television

commercials, billboards, governments, fundraisers, and businesses around the world react and

hustle to aid and assist those affected by tsunamis. There are many commercial applications of a

tsunami within the global market, the effects on insurance rates, and fundraiser changes

performed in light of these catastrophes.

When a tsunami strikes, the physical damage to the land and dwellings surrounding

ground zero are instantly devastating. However, the long term damage isn't seen right away.

Similar to a bruise on the arm, the damage isn't seen right away at the moment of impact to the

skin. It takes time for the wound to swell up and form a bruise.

The damage to the global markets are affected by tsunamis. For example, readers may

reflect on the 9.0 magnitude earthquake and tsunami hitting Japan on March 11, 2011. According

to the Wall Street Journal, companies such as Toshiba, SanDisk, Apple, Honda, Toyota,

Mitsubishi, Boeing, and Sony all suffered a loss in their production and distribution values for

the first quarter of earnings in 2011. The transportation of finished goods was hindered due to the

shut down and damage of some ports and/or roads. The pathways lead to the airports and

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shipping yards where the produced goods are transported (Clark & Takahashi 2011). This deeply

affects the global supply chain. Production is put on hold on mass goods, shipments are delayed,

consumers are empty handed, and stock prices drop. This is can happen swiftly, or over a long

period of time. Regardless, it's a real and underlying effect of tsunamis.

Once cameras and news reporters have switched their attention from headlining

tsunamis, there is still immense work and activity growth around any recent tsunami strike. One

industry that is established for such an endeavor is insurance. After reviewing the insurance

losses total for the recent tragedy in Japan, the amount of loss accrued is in the billions of dollars.

According to the Woodriff Sawyer and Co findings for the Japan earthquake and tsunami, the

projected insured losses between two major global insurers and reinsurers ranged from $20BN-

$30BN from AIR Worldwide, and $12BN-$25BN from EQECAT ("The Japanese earthquake"

2011). Due to the fact that the commercial and industrial insurance market in Japan is focused

towards a small percentage of non-life insurance businesses (who have not yet produced final

numbers of the total loss estimates for the tsunami), the natural disaster is predicted to have a

swift and visible effect on the local insurance market in Japan ("The Japanese earthquake" 2011).

One of the more common and seemingly expected results of any major disaster is an

increase in fundraising, Fundraiser and charity events are put forth by groups whom usually are

not directly affected by the incident. Celebrities throw benefit concerts and organizations launch

campaign aids on television. Nonprofit groups are in full force working to raise financial support

to aid those in need. Reflecting on the recent Japan tsunami, the amount of wealth given based

on charity events may surprise the public. The AARP online bulletin expresses that U.S.

organizations have donated a total of $24 million dollars to aid Japan in the most recent tsunami.

While the amount is appreciative, it does not compare to the $500 million that was raised to

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support Haiti after the 2010 earthquake (Hasson 2011). Perhaps the mindset of donators assumes

that Japan is a wealthier country and can afford their own clean up.

Charity organizations are also facing a lack of donations when it comes to a tsunami

strike. Small nonprofit organizations have seen a drop in donations when a major tsunami,

earthquake, or hurricane occurs. Those who have the option to donate to small/local groups

decide to send contributions to larger and national groups that have a direct plug into the global

relief outlet ("Nonprofits weigh effect" 2005). While the results of any charity fundraising

endeavors are applauded and appreciated, the outcome will greatly affect those involved on both

sides of the spectrum.

No matter what the incident is, the commercial application of a tsunami will always be a

focal point in the finishing touches of any natural disaster. No matter where a tsunami strikes,

people all around the world will feel the ripple not only in the physical sense, but also in the

marketing and underlying ties that are shared with one another. The devastation is vast, the

aftermath can seemingly never reach its climax, and the future commercial growth of those

impacted by a tsunami will always be left up to the tide.

Future Trends

Scientists are currently exploring ways of predicting future tsunami occurrences. Because

tsunamis are the direct aftereffect of earthquakes or volcanic eruptions, many researchers have

studied the tectonic plates of the earth and their relationship to tsunamis. For example, Paul

Mann, author of The risks of tsunamis in the Northern Caribbean, predicts tsunami activity to

occur in the Northern Caribbean based on the tectonic plates within the area. Mann explains that

evidence has “identified large, 35- to 40-km-long cracks forming in a shape similar to the

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dimensions of slump amphitheaters. Cracking indicates that these areas are close to failure in the

same mode as the older slump scars.”

Tsunamis are likely to occur based on the actions of these tectonic plate zones. Some of

these areas include the San Andreas fault zone of California (1,500 km in length), the Alpine

fault zone of New Zealand (600 km in length), and the North Anatolian fault zone of Turkey

(1,000 km in length) (Mann 2006). It is difficult to determine when the faults will erupt and

trigger their tsunami counterparts. Many scientists believe that various faults have yet to take

action and are long overdue by many years. Although the events cannot be predicted, researchers

have explored other alternatives to studying these situations.

It is unknown when massive earthquakes will take place in the future. However studying

past evidence of time and location has helped researchers in obtaining more information on

tsunamis. Scientists have looked at past history and the changes that have occurred over time.

Past history is investigated in hopes of finding common traits between the area’s tsunamis had

once hit. By studying the location of where tsunamis had once taken place, researchers can

document what things had occurred.

Jere Lipps, professor of integrative biology at the University of California, Berkeley, had

researched a couple of areas where calamity had struck. Lipps and his colleagues had found

evidence that in “the years preceding an earthquake that had triggered a tsunami, the coastal area

had sunk about a foot” (Dye 2005). Researching the sinking of land only applies to subduction

zones (oceanic plate is pushed under continental plate) however the information may help many

prepare for future tsunamis.

In relation to the findings on the sinking land, even more research had been studied

regarding the microorganisms living in the bodies of water. Lipps found that some organisms

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Figure 1.3 (pictured below) presents an example of a tilt

meter used by scientists.

“changed dramatically less than 15 years before that quake struck due to a relatively quick

change in the water and mud along the high tide line. Thecamoebians, which live only in fresh

water, disappeared, apparently because of the infusion of salt water as the coast subsided. Other

changes in fauna and microorganism populations told the same story” (Dye 2005). By studying

microorganisms in the bodies of water today, scientists may be able to determine if an

earthquake is likely to occur sooner or later.

To measure the sinking land in areas of these subduction zones, scientists have the option

of using a tilt meter. A tilt meter, shown in figure 1.3, provides researchers with information as

to when the surface of land has tilted slightly. Although the meter does not provide an estimated

time as to when the earthquake will strike, the information

obtained from the tilt meter can be used as a warning tool

for residents living in the area to evacuate or prepare for

the natural disaster.

With recent trends of natural disasters occurring

more frequently, individuals have questioned how to

prepare for the worst. In relation to tsunamis, a variety of

methods have been executed. These precautions include the

use of sirens, warning signs, mangrove trees, and protection

walls. The tools have helped educate and even protect the

public from the risks of tsunamis.

Siren sounds have helped community members in evacuating from potential tsunami

threats. This is due to the high pitch of the siren. These sirens have helped warned large groups

of individuals and in correlation, warning signs have helped educate residents as well as visitors

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of the potential risks of tsunamis in the area. By properly educating these risks to the general

public, individuals have the necessary background of the dangers associated within the area and

can prepare.

Mangrove trees and tsunami protection walls are used as a shield, blocking some of the

strong waves when a tsunami strikes. The purpose of a mangrove tree is to decreases the amount

of impact associated with the tidal waves. In lowering this impact, the damages caused by the

impact of water in the area may decrease as well. Protection walls play the same role as

Mangrove trees. They too are used to lower the rate of damage caused by tsunamis. The walls

can withstand a great force acted upon them and may reduce the amount of losses in the area.

These precautions are necessary for individuals whom live in the areas that tsunamis

could strike. It is important however for all individuals to be prepared for the unexpected.

According to The American Red Cross, one should know the height of the street above sea level

and its distance from the body of water. Persons should also plan a safe evacuation destination to

higher ground (above sea level) and if travelling, should become familiarized with the area. It is

unfortunate that natural disasters are overlooked by a majority of people. By properly preparing

for a tsunami, individuals have the background knowledge needed when the event occurs.

Many programs are developed to help educate people about the dangers of tsunamis and

how to prepare for them. It has been noted that “investing in early warning and disaster risk

reduction programs saves lives and is more cost-effective than recovery work” (A.R.C. 2009).

The American Red Cross explains that their organization focuses on “disaster risk reduction and

has supported community-based disaster preparedness projects across the tsunami-affected

region.” In particular, the organization currently has projects in Indonesia, Sri Lanka, Thailand,

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Kenya, Tanzania and Somalia that train the communities to recognize natural disasters and ways

to prepare for them.

Closing Remarks

It has been observed that tsunamis will strike without warning. Though no one can

predict when a tsunami will occur (yet), the basic understanding of tsunamis can be explained

through science and past history. The use of physics and has provided readers with information

on how a tsunami forms. History has unfolded over the course of many years. Past incidents have

even helped scientists’ research tsunamis. Through proper education and research, tsunamis can

no longer be classified as a misunderstood phenomenon.

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Works Cited

American Red Cross. (2009). No Title. Retrieved October 14th 2011 from http://www.redcoss.org

Author unknown. (2005). The Deadliest Tsunami in History? National Geographic News, 34-43.

Author unknown. (2005). Nonprofits Weigh Effect of Tsunami Giving on Fundraising. Retrieved on October 17th, 2011 from http://foundationcenter.org/pnd/news/story.jhtml?id=92200029

Buerk, R. (2011). Japan Earthquake: Tsunami Hits North-East. Retrieved from http://www.bbc.co.uk/news

Clark, D., & Takahashi, Y. (2011, March 12). Quake Disrupts Key Supply Chains. Retrieved at http://online.wsj.com/article/SB10001424052748703597804576194101663283550.html?mod=wsj_share_twitter

Dyes, L. (2005). Looking for Clues to Predict Future Tsunamis. ABCNews, 1-2.

Enchanted Learning, (Artist), A Cross Section of the Coast During a Tsunami, [illustration], retrieved October 25th, 2011 from Enchantedlearning.com

Hasson, J. (2011, March 15). Reaching Out to Japan in Crisis. Retrieved from http://www.aarp.org/giving-back/local-heroes/info-03-2011/fundraising-for-japanese-earthquake-survivors.html

James, C.D and Kozak, J.T. (1998). Historical Depictions of the 1755 Lisbon Earthquake. CA, USA: NISEE.

LiveScience Staff. (2004). Tsunamis in History. : Retrieved on October 14th 2011 from http://www.livescience.com.

Mann, P. (2006). The Risks of Tsunamis in the Northern Caribbean. Phi Kappa Phi Forum, 86.5, p21-25, 5p.

Phillips, C. (2011). The 10 Most Destructive Tsunamis in History. Australian Geographic, 1-3.

Simmons-Duffin, S. (2011). History Of Tsunami: The Word and the Wave. Retrieved from the National Public Radio.

Stevenson, D. (2005). Tsunamis and Earthquakes: What Physics is Interesting? Physics Today, 58:6, 10-11.

Than, K. (2006). Ancient Tsunami Devastated Mediterranean. MSNBC, 1.

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Von Feldt, R. (2004). Surviving the Tsunami- First Hour. Tsunami Survivor Stories. Retrieved October 20, 2011, http://phukettsunami.blogspot.com/2004/12/surviving-tsunami-part-2-first-hour.html.)

Woodriff Sawyer and Co. (2011). The Japanese Earthquake and Tsunami. Retrieved from http://www.woodruffsawyer.com/webmail/Briefings_Newsletters2011/Japan_Tsunami_Effects_March2011.pdf

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