Tsunamis are generated mainly by undersea earthquakes, which displace massive volumes of water, and can also be caused by landslides, volcanic eruptions, and rare extraterrestrial collisions. These seismic sea waves travel at high speeds across the ocean and can lead to catastrophic impacts on coastal areas when they approach land. The document also narrates personal experiences and the aftermath of a devastating tsunami that affected Sri Lanka, highlighting the destruction and loss of life.

1. Tsunamis Information and stories about tsunamis

2. What causes a Tsunami (1) An Undersea Earthquake - is the most common form of tsunami formation, typically generating the most destructive tsunamis. The earth is constantly moving on large tectonic plates . When these tectonic plates move past each other, collide and/or slide under one another (subduction), an earthquake results. This is what happened with the recent tsunami that devastated Southern Asia. Here, a massive earthquake in the Indian Ocean measuring 10.0 on the Richter scale jolted the seabed causing the sudden displacement of a very large volume of water. The earthquake temporarily produces a fluctuation in the mean sea level of a specified area. Waves quickly form as the displaced water tries to recapture equilibrium by filling the vacuum that was created. It should be noted that not all earthquakes generate tsunamis. Usually, it takes an earthquake with a Richter magnitude exceeding 7.5 to produce a destructive tsunami (2) Landslides – resulting in rockfalls, icefalls, or underwater (submarine) landslides or slumps can generate displacement of water to create a tsunami. More often than naught, submarine landslides are often caused by earthquakes, large and small, therefore strengthening the force of an earthquake induced tsunami. The most notable example of a landslide-induced tsunami can be traced to Southern France in the 1980’s where the movement of a significant amount of earth for the construction of an airport triggered an underwater landslide, which resulted in destructive tsunami waves hitting the harbor of Thebes. (3) Volcanic Eruption - Although relatively infrequent, violent volcanic eruptions represent also impulsive disturbances, which can displace a great volume of water and generate extremely destructive tsunami waves in the immediate source area. Volcanic disturbances can generate waves by the sudden displacement of water caused by a volcanic explosion, by a volcano's slope failure, or more likely by a phreatomagmatic explosion and collapse and/or engulfment of the volcanic magmatic chambers. The majority of tsunamis that occur in the Pacific Ocean happen around the “Ring of Fire” Area surrounding the Hawaiian Islands. The periphery has also been dubbed the 'Ring of Fire' because of the extraordinarily high number of active volcanoes and seismic activity located in the region. Since 1819, over 40 tsunamis have struck the Hawaiian Islands. One of the largest and most destructive tsunamis ever recorded was generated in August 26, 1883 after the explosion and collapse of the volcano of Krakatoa (Krakatau), in Indonesia. This explosion generated waves that reached 135 feet, destroyed coastal towns and villages along the Sunda Strait in both the islands of Java and Sumatra, killing 36, 417 people (4) Extraterrestrial Collision – Tsunamis caused by extraterrestrial collision (i.e. asteroids , meteors) are an extremely rare occurrence. Although no meteor/asteroid induced tsunami have been recorded in recent history, scientists realize that if these celestial bodies should strike the ocean, a large volume of water would undoubtedly be displaced to cause a tsunami. Scientists have calculated that if a moderately large asteroid, 5-6 km in diameter, should strike the middle of the large ocean basin such as the Atlantic Ocean, it would produce a tsunami that would travel all the way to the Appalachian Mountains in the upper two-thirds of the United States. On both sides of the Atlantic, coastal cities would be washed out by such a tsunami. An asteroid 5-6 kilometers in diameter impacting between the Hawaiian Islands and the West Coast of North America, would produce a tsunami which would wash out the coastal cities on the West coasts of Canada, U.S. and Mexico and would cover most of the inhabited coastal areas of the Hawaiian islands.

3. Tsunamis (pronounced tsoo-nah'-mee), or seismic sea waves, potentially the most catastrophic of all ocean waves, are generated by tectonic displacement--for example, volcanism, landslides, or earthquakes--of the seafloor, which in turn cause a sudden displacement of the water above and the formation of a small group of water waves having wavelength equal to the water depth (up to several thousand meters) at the point of origin. These waves can travel radially outward for thousands of kilometers while retaining substantial energy. Their speed--characteristic of gravity waves in shallow water and thus equal to the square root of gD, where g is the gravitational constant and D is the depth--is generally about 500 km/h (300 mph), and their periods range from 5 to 60 minutes. In the open ocean their amplitude is usually less than 1 m (3.3 ft); thus tsunamis often go unnoticed by ships at sea. In very shallow water, however, they undergo the same type of increase in amplitude as swell approaching a beach. The resultant waves can be devastating to low-lying coastal areas; the 37-m (120-ft.) waves from the 1883 Krakatoa eruption, for example, killed 36,000 people. The characteristics of tsunamis as they approach shore are greatly affected by wave refraction over the local bathymetry. Tsunami-producing earthquakes usually exceed 6.5 on the Richter scale, and most tsunamis occur in the Pacific Ocean because of the seismic activity around its perimeter. A tsunami warning system for the Pacific Ocean has been established; it consists of strategically placed seismic stations and a communications network. Tsunami Facts

4. TSUNAMI PICTURES OF COURSE THESE ARE FAKE

5. Real tsunami pictures

6. Drowned in Train As most of you know, my homeland of Sri Lanka was hit by a devastating tsunami, December 26th. What you may not know, is that it was my mother's home town of Galle was one of the hardest hit towns. As of now, I have personally lost an uncle, aunt, and cousin. They were all on a train bound to Galle from the capital city of Colombo, where they had gone for a weekend getaway. The train was swept out to sea when the tsunami hit. My oldest cousin, Padmal, who was also on the train, managed to swim to safety, however, my uncle, aunt, other cousin, and thousands more that were on that train, were not so lucky. They have already found the body of my cousin, Taja...she was only 17 years old and a budding artist. They have yet to find the bodies of my uncle and aunt...and many more Sri Lankan that have been either washed out to sea or buried under rubble of destroyed buildings.

7. Before and after pictures of terrifying tsunamis Now these may look bad but the islands like this today are still in bad condition. Some of them don’t look bad but just imagine over time. Little left, no population, just imagine the homeless people. Sitting on the beach when you react to a deadly wave. You can run from it, but you can not stop it. Your house underwater, missing friends, family, or unknown people to you. Now those missing people today are pronounced dead. What if this was your life up above, would you be shocked. We can only hope that no tsunami will come and destroy life and people.

8. Disappointment after the tsunami many people that lost their homes in a tsunami can be homeless. There are thousands of people like this. After a tsunami, it left people foodless and they had to eat rotted, poised, contaminated, or already ate an food on there on risks. You could get many diseases after a tsunami such as; Malaria. And many more flu's that can be deadly.

9. MY TSUNAMI STORY A nice, calm day on the beach. My mind set on the beautiful sun, blazing down on me. The palm trees swaying with the drift of the wind, waves smacking down on the surface of the water. All kinds of people in the water laughing, screaming, swimming to the surface, or being swept with the current back to shore. I started to feel nauseous and getting headaches for being in the sun way to long. I took a swim in the ocean and the cold water felt amazing on my body. After being in the water for quite two hours at least far out in the ocean where peoples faces were blurry from the shore, up ahead this massive wave was coming directly to me and the other people looking with shock. The calm people in the ocean screamed with terror in the water. Me and the rest of the people swimming back to the ocean shore. The wave was about 30 feet away from smacking down right on us was to soon to even say it.

10. My resources used www.google.com/tsunamiinfo www.tsunamiorganization.org www.tsunamidisaster.com www.tracktsunami.com Books I used Tsunami Terror TSUNAMIS