How do tsunamis occur


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How do tsunamis occur

  1. 1. How do Tsunamis occur? Tsunamis
  2. 2. This is Three ways Tsunamis Start Step 1) This is three ways a Tsunamis can be started: 1*Volcano 2*Land Slide 3*Earthquake
  3. 3. This is a Tsunami travelling Step 2) This is when a Tsunami is travelling it is not as visible in the deeper water but it make the Tsunami faster.
  4. 4. Step 3) This is when the Tsunami slows down and grows bigger This is when the water is building up and getting closer to land.
  5. 5. Step 4) This is when a Tsunami is happening it has built up from the sea and the shallow water that I crashing on the town or city. This is when a Tsunami is Happening
  6. 6. Step 5) This is what happens after a Tsunami and the people the survived have to start their families and life all over again.
  7. 7. Step 4 The waves crashes on the beach or land. Step 3 The wave slows down in the shallow water and it visible to see and it gains height. Step 2 While a Tsunami is travelling is gains speed in the deeper water but it is not as visible in the deep water. Step 1 A Tsunami is coursed by Volcanos, earthquakes and Land slides Step 5 After the Tsunami with all the destruction
  8. 8. And another way
  9. 9. This is how a Tsunami occurs The deeper the water the faster it is In the shallow water The bigger it is
  10. 10.                                                                                        WALT compare and contrast Task: Compare and contrast two photos. One before you natural disaster occurred and one after. Success Criteria: How will I know when i have been successful?  - I can identify what is the same in the two photos  - I can identify what is different in the two photos  - I can explain why these changes have occurred                                                                                                                               <><>  Before *The waves are at right height *The waves just reach the beach  *The road is still in sight *The houses are still standing and are not smashed *It is clean water *The houses are standing the train track it ready for a train. *The waves fresh and the water the right blue and green    After *There is a flood. *The tide is right up. *The road is half fill from the water from the Tsunami. *Its dirty water *The house have been flooded and smashed *The houses are all flooded and some are even under water. *Some houses have been moved around and have been smashed *He tide is high and the water has been swept across the water and the covered the train track with water *The water is very dirty and the has made the sea dirty                                                                                                   After Before
  11. 11. The Patiki (The Hooks) Once in a land long ago in 1862, it was a sunny day as peaceful as can be. People were washing their clothes in the river and weaving their blankets made out of flax, but the only problem was … There was barely any food. The god of the Land the one person that told the village what they can do and what they can’t, the ruler came and told them if they want to live here, you cannot fish in the ocean. The people in the village knew that they were not allowed to fish in the ocean or there would be consequences from the sea goddess – the one who creates Tsunamis, whirl pools and the one who owns the sea for the village. So the people were sick and tired of looking for food. In the Tairua bar everyone was complaining that the food was disgusting and boring. They really wanted the fish. Only one person had tasted the fish and that was the village leader. He got it off the beach – it had been washed up from the ocean. So they strolled off to tell the village leader, who takes care of the village, and the leader of the Tairua village, of their idea. As they got to the leader of the villages hut, the village leader could tell they were coming. ”What are you doing here, shouldn’t you be asleep,” called the village leader. The village people called out NO. The reason we are here is because we have no food apart from the berries and fruit, but we are sick of that food – “we want fish” screamed the villagers. The village leader came out and said that they couldn’t – the land god told us that if we fish in the sea there will be consequences. But the village people didn’t care they wanted the fish so as soon as midnight hit they rowed off out to the open sea .When they thought they were far enough out they would be ready to put berries down and worms on a stick that was tree sticks with a rock on the end. They finally dropped the fishing stuff and suddenly they got tugs and everyone started to get bites on the fishing sticks. As soon as they pulled the fish up everyone had around 30 fish. When the sun was about to rise they knew that if the village leader found out they were fishing they would be in trouble and he would panic like a monkey. Later that day the sea goddess was complaining that people were fishing in her, the earth god had no idea. “That’s it I warned you so now you are going to get it”, called the sea goddess. How was the earth god going to warn the people? A little girl was walking along the beach but then she saw it was a tsunami coming straight for Tairua. The little girl ran as fast as she could, screaming that there is a tsunami coming, there is a tsunami coming. Only a few people could hear her. The people that could hear her were all running up to the highest part of the hills. They saw the people getting hit. It was the worst thing that they had seen in their life. After the tsunami left the people went to see the destruction. There was no sight of the people that had died. The sea goddess was finally happy as she told the people there would be consequences. The land god was furious as ever but the people just wanted food. But he told them it was their fault. The land god knew that that had to happen but now there will be no food because all the trees are gone and their plants. But he had to make a deal. Normally there are 250 people but now there are only 60 people. He yelled out for the sea goddess. She called back “what do you want. I was enjoying my relaxing day out with Patiki (hooks). The land god had to talk to the sea goddess and tell her that if they don’t fish they wont have any food, and if they eat it, it might be good for them and they may get smarter and invent new food. Then they won’t have to fish out of your beloved sea. The sea goddess was still not impressed but it would be good if that could happen. The sea goddess had one request about this arrangement. “The only thing I hate about it is that it hurts when they drop the Patiki (hooks) in me.” They have to think of something - they could put the bait over the hooks so that is wont hurt as much thought the land god. “Well don’t you already put that bait stuff on it?” asked the sea goddess. The land god just thought that they had to try it. And remember sea goddess, that fish could be good for the brain. By Katie Lush
  12. 12. Looks Like * Before Lush *After trees gone *The sea is muddy *Before everyone having a peaceful morning * Sweeping water running over land Feels like *Heart beating/ Rising *Drowning *Shaking (Body) *Scary *Before- Happy *Before- Peaceful *Unhappy *Creepy *Your in a nightmare *Upsetting *Getting smashed like when you ride a wave and you fall off and you tumble though the water. *Wave Sucking you out to sea Sounds Like *Sirens' going off Crashing *Screaming people/ animals *Before- Birds cheeping *Before- Kids playing *Screaming like they are going to die *Gushing water *Sounds like when a big wave is crashing on me, my ears blocked and they are ringing *Swishing of waves.
  13. 13. <ul><li>How does a tsunami occur? Title </li></ul><ul><li>As a tsunami leaves the deep water of the open ocean and travels into the shallower water near the coast, it transforms. A tsunami travels at a speed that is related to the water depth - hence, as the water depth decreases, the tsunami slows. The tsunami's energy flux, which is dependent on both its wave speed and wave height, remains nearly constant. Consequently, as the tsunami's speed diminishes as it travels into shallower water, its height grows. Because of this shoaling effect, a tsunami, imperceptible at sea, may grow to be several meters called a runup height, of 10, 20, and even or more in height near the coast. When it finally reaches the coast, a tsunami may appear as a rapidly rising or falling tide, a series of breaking waves, or even a bore. </li></ul><ul><li>As a tsunami approaches shore,  it begins to slow and grow in height. Just like other water waves, tsunamis begin to lose energy as they rush onshore - part of the wave energy is reflected offshore, while the shoreward-propagating wave energy is dissipated through bottom friction and turbulence. Despite these losses, tsunamis still reach the coast with tremendous amounts of energy. Tsunamis have great erosional potential, stripping beaches of sand that may have taken years to accumulate and undermining trees and other coastal vegetation. Capable of inundating, or flooding, hundreds of meters inland past the typical high-water level, the fast-moving water associated with the inundating tsunami can crush homes and other coastal structures. Tsunamis may reach a maximum vertical height onshore above sea level, often 30 metres. </li></ul>Telling how it moves in the water About it growing The height that it grows. How it works. Paragraphs Can grow big and can curse a lot of damage
  14. 14. <ul><li>The Asian tsunami: why there were no warnings (Think Write) </li></ul><ul><li>By Peter Symonds--------Author Title 3 January 2005--------Date </li></ul><ul><li>As the horrifying toll of death and destruction continues to mount in southern Asia, it becomes ever more obvious that lives could have been saved if a tsunami warning system had been in place. With just 15 to 30 minutes notice, and clear directives to flee, many people who had no idea what was happening, or how to react, could have escaped to safety. </li></ul><ul><li>The tsunami and the earthquake that triggered it are natural phenomena. While earthquakes cannot be forecast they can be quickly pinpointed. Moreover, if the appropriate scientific equipment is in place, the formation of a tsunami can also be detected and its likely path predicted and even tracked. </li></ul><ul><li>A tsunami warning system has existed in the Pacific Ocean since the late 1940s. It was substantially upgraded after a tidal wave, triggered by a massive earthquake, killed more than 100 people in Alaska in 1964. In addition to seismological instruments that register tremors, a network of sea level gauges and deep-sea sensors or “tsunameters” linked by satellite to round-the-clock monitoring stations is based in Hawaii, Alaska and Japan. Using computer modelling, scientists can predict the likely propagation of tsunamis and their probable impact. </li></ul><ul><li>There is no such system in the Indian Ocean. Of the 11 countries affected by last week’s calamity, only Thailand and Indonesia belong to the Pacific Ocean tsunami warning system. Most of the nations have seismological units that detected the earthquake. Not all quakes, however, generate tsunamis. In the absence of planning, preparation and additional equipment, it is difficult to make accurate predictions. And time is of the essence, since tsunami waves travel at speeds of up to 800kmh, depending on the depth of the water. </li></ul><ul><li>The December 26 earthquake registered 9 on the Richter scale, making it the largest since the Alaskan quake and one of the most massive in the last century. The epicentre of the initial tremor was off the northwest coast of the Indonesian island of Sumatra, followed by a series of aftershocks that ran north through the Andaman and Nicobar Islands in the Bay of Bengal. Two tectonic or continental plates—the Asian and Indian—shifted along a 1,000km fault line by as much as 20 metres, releasing energy equivalent to more than 20,000 nuclear bombs of the size dropped on Hiroshima in 1945. </li></ul><ul><li>The quake occurred just before 8 a.m. Sumatran time [1 a.m. GMT]. Eight minutes later, an alarm was triggered at the Pacific Tsunami Warning Centre in Hawaii by seismic signals transmitted from stations in Australia. Three minutes after that, a message was sent to other observatories in the Pacific. At 8.14 a.m., an alert notified all countries participating in the network about the quake, indicating that it posed no threat of a tsunami to the Pacific. </li></ul><ul><li>An hour later, the centre revised its initial estimate of the siz e of the tremor from 8 to 8.5, and issued a second alert, warning of a possible tsunami in the Indian Ocean . Frantic phone calls were made to issue warnings. But without procedures in place for the Indian Ocean, it was hit and miss. “We started thinking about who we could call. We talked to the State Department Operations Centre and to the military. We called embassies. We talked to the navy in Sri Lanka, any local government official we could get hold of,” geophysicist Barry Hirshorn told the Honolulu Advertiser . Place </li></ul><ul><li>In the countries in the path of the tsunami, the response was disorganised and lethargic. The few who were aware of the dangers were hampered by lack of preparation, bureaucratism and inadequate infrastructure. Others either did not know how to interpret the warning signs, or were indifferent to them. None of the countries surrounding the Bay of Bengal issued an official warning, leaving millions of people completely at the mercy of the approaching waves. </li></ul><ul><li> </li></ul>Reference Place Problem/ Blurb Extraordinary Main idea
  15. 15. Thank you for Watching my Natural disaster Slide Show
  16. 16. Thank You for watching my Slide show Created By Katie Lush All photos from Google images