Name: Lauren AttardiLearning 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 earth-quake, vertically displaces the water column? -A large amount of waves are generated since a Tsunami is known as a wave train, the waves come one after another and can continue for up to hours after the earthquake. 2. 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? -A strike-slip fault can’t cause a tsunami due to the movement being horizontal, not vertical unlike that of normal and reverse faults. This horizontal movement keeps there from being a vertical displacement of the water.3. How dangerous are tsunami waves in the open ocean? And why?-In the deep open ocean, the waves are not so dangerous due to the depth of the ocean so thewaves tend to be gentle and large.4. Which is the more dangerous location for a tsunami, a straight stretch of open coast or a bay? Why?-A bay is a more dangerous location for a tsunami because the area in which the waves have to stretch is smaller and narrower. Thus, giving less an area for the energy to be released.5. What is often the first indication of the arrival of a tsunami at the coast?-The first indication of a tsunami is typically a rapid drop in sea level. 6. 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?-The tsunami would reach the coast in under an hour. 7. What are the approximate times between tsunami wave crests?-The time between crests is about 10-30 minutes.8. Which wave of a major tsunami is likely to be the highest – first, fourth, tenth?-The fourth wave is likely to be the highest. 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)?i. A major earthquake.b. Where, specifically, was that initial event?i. The event occurred off the southwest coast of Sumatra.c. What secondary event (the one that killed most of the people) was caused by the initial event noted above?i. The second event that occurred due to the first event was a tsunami, this what devastated the population.d. Explain (concisely and in detail) exactly how the initial event was related to the secondary event?i. The earthquake caused the tsunami when fault movement on the ocean floor suddenly pushed up a large mass of water.10.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 implica-tions based on records of past events.- There haven’t been any large earthquakes because the subduction zone is locked. The last major earthquake was in 1700. Giant earthquakes happen every few hundred years, and the next major earthquake could come any time.11.On low-lying coastal flats near Anchorage, Alaska, the foundations of buildings dropped be-low 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?i. subduction zone boundary; the Pacific Ocean floor is descending under the continental marginb. Explain what tecontic forces led to the ground sinking and later rising.i. While the subduction zone fault was locked, descent of the ocean floor pulled down the edge of the continental margin, causing it to slowly buckle up. Release of the boundary during the earthquake permitted the ground to drop suddenly and the sea move in.12.What type of event has repeatedly generated high tsunami waves in Lituya Bay of south-eastern Alaska? Be specific. (Case in Point: Immense Local Tsunami from a Landslide, LituyaBay, Alaska, 1958)- large rockfall (or landslide) triggered by a nearby earthquake13.List some of the ways volcanoes can generate tsunami.-waves may be generated by the sudden displacement of water caused by a volcanic explo-sion, by a volcano's slope failure, or by the collapse of the volcano chambers.14.How are tsunami waves in the Atlantic Ocean likely to be generated?- Most tsunamis are generated by shallow earthquakes in subduction zones,15.Why are even good swimmers often killed by tsunami waves?-Even good swimmers are often killed by tsunami waves because of many reasons, one being the water rises extremely suddenly and rapidly during a tsunami. The waves also move with such force and at such high speeds its almost like a riptide. All of this one top of the debris thatgets mixed into the rising water makes it much harder than just swimming in a deep pool or a deep part of the
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