Name: Joshua FernandezLearning Unit 5: Tsunami Review QuestionsThis assignment is designed to assess your understanding of Unit 5 and includes some of the Questions for Review at the end of Chapter 5 from your text plus a few additional questions. Each question can be answered in one to two sentences. Please limit yourself to a maximum ofthree sentences. Access the assignment, complete it with ANSWERS IN A DIFFERENT COLOR FONT as a separate file, and send it back for evaluation and grading through the assignment tab by or before the due date. 1. How many tsunami waves are generated when an abrupt disturbance, such as an earthquake, vertically displaces the water column? - Around 10 or more2. Of the three main types of fault movements—strike-slip faults, normal faults, and reverse (thrust) faults—which can and which cannot cause tsunami? Why? - Normal and thrust faults can, strike-slip faults cannot. Normal and thrust faults do displace water and strike-slip faults do not displaced water3. How dangerous are tsunami waves in the open ocean? And why?- These waves are not dangerous in open ocean because the height of the waves are smaller than the wave length. Also time between crests is long4. Which is the more dangerous location for a tsunami, a straight stretch of open coast or a bay? Why?- A bay because it focuses the wave making the water go into a narrower area causing the wave to rise5. What is often the first indication of the arrival of a tsunami at the coast?- And fast drop in ocean/sea level6. For a subduction-zone earthquake off the coast of Oregon or Washington, how long would it take for a tsunami wave to first reach the coast?- About 20 minutes or less7. What are the approximate times between tsunami wave crests?- From 10-35 minutes, it is usually 30 minutes on average8. Which wave of a major tsunami is likely to be the highest – first, fourth, tenth?- Fourth 9. In December, 2004, a pair of closely related natural disasters killed tens of thousands of people. (Case in Point: Lack of Warning and Education Costs Lives, Sumatra Tsunami, 2004)a. What was the initial event (not the one that killed most of the people)?- A major earthquakeb. Where, specifically, was that initial event?- It was by the southwest coast of Sumatrac. What secondary event (the one that killed most of the people) was caused by the initial event noted above?- A tsunamid. Explain (concisely and in detail) exactly how the initial event was related to the secondary event?- A tsunami was caused by the initial earthquake because of the fault movement on the ocean floor, pushing a lot of water up10.There have not been any very large earthquakes on the subduction zone of the coast of Washington and Oregon in hundreds of years. Explain why not and what are the implications based on records of past events.- Because the subduction zone is locked and the last earthquake was in 1700. Since major earthquakes happen rarely, a major one could happen in the future11.On low-lying coastal flats near Anchorage, Alaska, the foundations of buildings dropped below sea level during the giant 1964 earthquake. Decades later, their foundations are again above sea level. (Case in Point: Subduction Zone Earthquake Generates a Major Tsunami)a. What type of tectonic boundary caused the earthquake, and what plate motions are involved?- Subduction zone boundary, the ocean floor is going under and descendingb. Explain what tectonic forces led to the ground sinking and later rising.- Due to the subduction zone being locked, descent of the ocean floor pulled down thecontinental margin, release of the boundary during the earthquake allowed the ground to drop all of a sudden and allowed the sea to move in, years and decades later, the edge of the continent is rising since the subduction zone is locked once again.12.What type of event has repeatedly generated high tsunami waves in Lituya Bay of southeastern Alaska? Be specific. (Case in Point: Immense Local Tsunami from a Landslide, Lituya Bay, Alaska, 1958)- A large landslide that was caused by a nearby earthquake13.List some of the ways volcanoes can generate tsunami.- Volcanic earthquakes, undersea eruptions, landslides, lahars, pyroclastic flows14.How are tsunami waves in the Atlantic Ocean likely to be generated?- Not likely but it is still possible, it is because of the lack of subduction zones15.Why are even good swimmers often killed by tsunami waves?- Because of the speed and pressure of the wave along with the objects the wave carries in its
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