Name: ____Rebecca Gallanter____Learning Unit 8: Coast Review QuestionsThis assignment is designed to assess your understanding of Unit 4 and includes some of the Questions for Review at the end of Chapters 3 and 4 from your text plus a few additional questions. Each question can be answered in one to two sentences. Please limit yourself to a maximum of three 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 can there often be big waves at the coast when there is little or no wind?Those waves are often started up by winds that originate offshore, and the waves then travel from their starting point thousands of miles in order to appear on the beach2. What force creates most waves? What factors influence the size of most waves?Waves are created by strong winds. The main factors that influence the size of the waves are greater wind, which is the velocity, the amount of time that the wind is blowing for, and greater fetch3. Why do waves not break in the open ocean?The wave only breaks when it gets closer to shore because of the shallower water. Itdoesn’t have the space in the trough because the wave base is now being cut by shallow water.4. Describe what happens to waves as they enter shallow water.When the wave was out in the open ocean, it had a lot of room to roll and each crest was able to complete. However, as the wave pulls into the shore, it begins to encounter shallow water. Because the wave base does not have as much room anymore, it is not able to complete a full rotation and the wave’s crest beaks as it moves up hill into the shallow water onto the shore. 5. Where does beach sand originate?The sand that people sea on beaches originally came from sea cliff Erosion and was also sediments that came from rivers as the water ran into the sea from the coast. 6. Why does sand gradually migrate along the beach? Briefly explain.The sand on the beach originally came from erosion of rocks by the sea water and was carried to the land by the ocean waves. The rivers also contributed by supplying sediments in their own runoff. The sand and gravel that was supplied to the coast is then moved by the waves. 7. Why do barrier islands gradually migrate landward with time? What evidence is there that a barrier island has migrated landward with time?For barrier islands, the sea level rises, which causes them to erode and to shift toward the mainland over time. 8. Which side of a beach groin collects sand?The side of the beach that collects sand is the side updrift of the structure 9. List the purpose and effects of seawalls, groins, breakwaters and artificialreefs, an jetties?Seawalls are built to protect property landward of an already eroded, small beachGroins are built to trap sand being carried by longshore drift and build up the beachupdrift of the structureBreakwaters are built offshore and parallel to the shore, have a similar effect, causing deposition in the protected area behind the breakwater and erosion on the downdrift side.Artificial reefs are usually built for the purpose of promoting marine life and the dissipation of wave energyJettis- are built to maintain an open inlet by blocking the movement of sand by longshore drift10. Why is piling riprap boulders or building a seawall to protect a sea cliff or beach houses not a good solution to erosion? Explain what happens.By building seawalls, it can make the erosion happen faster. When the water hits the sea wall with a lot of force, it then pulls out with a lot of force. The beach then narrows and it becomes steeper and the water that is in front of the sea wall is starting to get deeper and deeper. From all of that occurring, larger, more dangerous waves come to the shore like, which speed up the erosion process and keep hurting the beach. 11.Where does the sand go that is eroded from a beach during a storm?That sand is carried by waves to locations just off shore. 12.Where would a sand spit form on a barrier bar island relative to the direction of longshore drift?It would form that sand spit where a linear beach is and it would be extending off from the mainland.13.What is a better solution than the variety of erosion-prevention efforts used on most coasts?One option that has seen better results has been beach replenishment. They are large scale efforts and often cost a lot of money.14.Why is sand from dunes or lagoons not very good to replenish beaches?The problem with sand from dunes and lagoons is that sand from offshore beaches istypical finer than natural deposited beach sand and therefore easily eroded.15.With large-scale replenishment of sand on beaches by the Corps of Engineers, who generally pays most of the tens of millions of dollars it costs? It usually comes out of the pocket of tax
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