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CHAPTER 5 TSUNAMI THE GREAT WAVE Correct answers are indicated by an asterisk both in short answer and multiple choice questions True or False questions can be easily prepared from multiple choice questions Web Sites http www asiantsunamivideos com Video Clips of the Asian Tsunami http www ngdc noaa gov seg hazard tsu shtml http www pbs org wnet savageearth tsunami index html http www pmel noaa gov tsunami http www tsunami noaa gov http www tsunami org http www1 tpgi com au users tps seti spacegd7 html Videos Geologic Hazards Slide Sets Tsunami National Geophysical Data Center NOAA Dept 930 325 Broadway Boulder CO 80303 CHAPTER 5 End of Chapter Answers 1 What are three of the main causes of tsunami sub sea earthquakes landslides into a body of water volcano flank collapse into a water body sub sea volcanic eruptions asteroid impact into an ocean 2 Of the three main types of fault movements strike slip faults normal faults and thrust faults which can and which cannot cause tsunami Why strike slip cannot normal and thrust faults can strike slip faults do not displace water normal and thrust do displace water 3 About how high are the largest earthquake caused tsunami waves in the open ocean about 15 meters 4 How does the height of a tsunami wave change as it enters a bay Why wave height increases Since more water of each wave is forced into a narrower area the height must rise to accommodate the volume of water 5 How many tsunami waves are generated by one earthquake ten or more 6 How fast do tsunami waves tend to move in the deep ocean about 760 km hour or 475 mi hour 7 Do tsunami speed up or slow down at the coast Why They slow down because the waves drag on and are held back by the shallower bottom 8 Why is even the side of an island away from the source earthquake not safe from a tsunami because the waves can refract around the coast of an island to strike the opposite side 9 For a subduction zone earthquake off the coast of Oregon or Washington how long would it