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Study guide from chapter for weekly quizzes and unit exams...

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Dakota Bartsch A01823843 Unit 1: Assignment 4

Exam 1 Study Guide: Part 4 Chapter 4: Tsunamis Instructions: Use the chapter 4 reading and lecture materials to answer the following questions. Some questions have multiple parts so carefully read the questions and provide detailed and specific responses. Generally, the difference between a good grade and a poor grade on an assignment is based on whether or not the questions were answered completely. The purpose of this assignment is to test your understanding of course materials covered from Chapter 4. Additionally, this assignment doubles as Part 4 of the Exam 1 study guide. 1. Define tsunami and list the ways tsunamis can be triggered. How are tsunamis typically produced? (1 pt) ‘Tsunami’ is ‘Harbor wave’ in Japanese. They occur as a result of a sudden vertical displacement in the ocean. Displacement can happen from earthquakes, underwater landslides, volcanic eruptions, collapse of a volcano into the ocean water, or the impact of an asteroid or comet in the ocean. These usually cause a sudden increase in the ocean level and rapid flooding. 2. Describe the four-stage process that leads to tsunami waves. (1 pt) 1. An earthquake uplifts or downshifts the sea floor, this causes a dome of water to form above the rupture. The dome collapses and sends rippling waves outward. 2. The tsunami waves move rapidly, but are fairly small and spaced out, barely recognizable. 3. As it nears land, the tsunami begins to slow down, and waves collect on top of each other, they gain height and frequency. 4. The tsunami moves inland, destroying everything in it’s path. Reaches all the way to it’s runup, the furthest horizontal and vertical distance of the largest wave. 3. Define distant and local tsunamis. (1 pt) When the original dome of water collapses, it sends waves in all directions. One results in the ‘distant tsunami’ which travels at high speeds for thousands of miles before it reaches land. The other causes a ‘local tsunami’ because the initial rupture is closer to land, the tsunami arrives faster and gives residents little warning. 4. What are the primary and secondary effects of tsunamis? (1 pt) Primary effects of a tsunami come directly from the flooding and water impact. These can include erosion, building damage, loss of vegetation, and changes in beaches. Secondary effects are found in the days and weeks following the event and can include pollution or unsanitary water, disease breakouts, rotting plants and animals, and possible fires. 5. How do growing populations and land use influence the consequences of tsunamis? (1 pt) Tsunamis are very rarely caused by humans, but effects and losses from tsunamis are

increasing because populations are growing and living in coastal areas. These growing populations can reduce the consequences by leaving a buffer zone of forest along the coastline, reinforcing buildings to withstand sudden flooding, and moving some large populations and structures more inland, to keep them at a safe distance from the hazard. 6. What are structural control options to reduce tsunamis? Are they fool-proof? (1 pt) Building designs for large buildings can be created to reduce the destruction caused by tsunamis. It is hard to predict if they will be 100% effective, as tsunamis can come at unexpected times with unexpected force. Building sea walls are an option to structurally control tsunamis. They are built in the ocean with the strength to not allow a tsunami to pass by them to reach land. The problem is that it is hard to know how high to construct them, and they can provide the population with a false sense of security, thus they are not fool-proof. 7. How can vegetation help minimize tsunami damage? (1 pt) Vegetation along coastlines can minimize tsunami damage because they can slow the waves, acting as a cushion between the ocean and villages. They won’t completely stop the wave and save everyone from damage, much of the vegetation will be torn out and become debris in the water, causing greater hazard. 8. How can education minimize potential consequences of tsunamis? (1 pt) When a population is educated about tsunamis, including warning signs, potential hazards, safer places to evacuate, and the difference between a ‘tsunami watch’ and a ‘tsunami warning,’ many lives will be saved. A tsunami watch means that an earthquake that could cause a tsunami wave has occured. A tsunami warning means that a tsunami wave has been detected and is coming towards land. People should be taught that tsunamis come in multiple waves, and they should know that the water that floods the city will return to the ocean full of debris and will be just as dangerous as the initial tsunami. 9. Describe how to obtain tsunami ready status. (1 pt) For a community to be ‘tsunami ready,’ it must a. Have a 24-hour emergency operation center. b. Establish ways to receive tsunami warnings from weather and tsunami monitoring organizations. c. Have ways to communicate hazards, watches, and warnings to the public. d. Develop a tsunami preparedness plan with emergency drills. e. Organize a community awareness program to educate the population. 10. What should you do if a tsunami warning is issued? (1 pt) If a tsunami warning is issued, or you feel these warning signs, you should: a. If you feel an earthquake, you need to leave the coastal area immediately. b. If the ocean recedes, you also need to leave and travel to higher ground. c. Do not assume that all locations are safe.

d. The time between waves can be up to an hour, or a tsunami lasts for a long time, stay safe and wait for an all clear to return to lower ground. e. If you hear sirens, evacuate immediately. f. If the tsunami seems small where you are, it can be much larger in another area nearby. g. If all else fails, climb a tall, strong tree. h. Find something that floats to use as a raft....