OCE1001, INTRODUCTION TO OCEANOGRAPHY, Fall, 2018 THIRD MID-TERM EXAMINATION Test No. 0001 Name: ______READ THIS!!!! Put your name in the blank above. Read all questions carefully, and answer only the question which is asked. You may find the following equations useful: C = (gL/2) = 1.25 L (m/s) Where: C = speed of a wave and: g = gravity = 9.8 m/s2 C = (gD) = 3.1 D (m/s) L = wavelength of a wave C = 1.56 T (m/s) D = water depth C = L/T T = period of a wave

PLEASE WRITE NEATLY. Matching: The Are Moving (8 pts) Do not put these on the scantron sheet. ____ neap ____ hook A. worldwide change in level. B. structure intended to widen a . ____ jetty ____ groin C. wall intended to keep a open. D. two high and two low tides per day. ____ eustatic E. parallel to the caused by waves. ____ semidiurnal F. twice monthly tide that with a smaller than average range. ____ marine terrace G. bend in end of a caused by wave refraction. ____ longshore current H. region eroded flat by waves, elevated above sea level. ____ longitudinal I. disturbance of wave is parallel to wave movement

Multiple Choice: (2 pts each) Put the answers to these questions on the scantron sheet. 1. In Figure 1, the features labeled 1, 2, 3, 4, and 5 are, respectively: a. spit, barrier , , hook, . b. hook, spit, baymouth bar, , tombolo. c. tombolo, spit, baymouth bar, barrier island, hook. d. spit, barrier island, baymouth bar, hook, tombolo. e. hook, barrier island, baymouth bar, tombolo, spit.

2. Your best strategy if you are caught in a is to: a. accept inevitable death. b. swim back to shore directly against the current. c. swim parallel with the shore until out of the current, then swim back to shore. d. swim with the current until it reverses and takes you back to shore. e. float with the rip current until it stops, and catch another rip current back to shore.

3. You are scuba diving 20 m deep below the surface of the ocean, while waves with a 2 m height and a 10 m wavelength are moving by on the surface. You feel yourself being: a. moved in a circular motion. b. unaffected by the waves above. c. moved in an elliptical motion, with a vertical long axis. d. moved horizontally only, back and forth. e. moved in an elliptical motion, with a horizontal long axis.

4. The PERIOD of a wave is: a. the number of waves that pass a given point in a given time. b. the distance from the top of a wave to the still water level. c. the time it takes for an identical point on two successive waves to pass a given point. d. the name for the motion of a particle of water in a water wave. e. the depth to which waves can "feel" the ocean bottom.

5. If we follow the motion of water in a shallow water wave, it will move: a. with the wave, as a mound of water moving over the ocean. b. vertically only, up and down as the wave passes by. c. elliptically, with the shape of the ellipses getting taller as the bottom is approached. d. elliptically, with the shape of the ellipses getting flatter as the bottom is approached. e. in circles, with the size of the circles increasing as the bottom is approached. 1

6. Given the conditions that usually lead to large waves, the largest wind waves would most likely be found: a. in the Antarctic Ocean. b. in the Red Sea. c. on the Great Lakes. d. in the equatorial Atlantic Ocean. e. in the North Atlantic Ocean.

7. The most important cause worldwide of waves, in terms of total energy yearly, is: a. none of these. b. meteorites. c. earthquakes. d. tides. e. winds.

8. You jump into the surf, play for a while, and notice when you get out that you have been swept down the beach a considerable distance. You have been affected by: a. a tidal current. b. a rip current. c. a seiche. d. a longshore current. e. constructive wave interference.

9. If waves are approaching a groin from the northeast (Figure 2), then the beach on the west side of the groin will become ___ while the beach on the east side of the groin will become ___. a. narrower, wider b. wider, narrower c. narrower, narrower d. wider, wider e. the waves will have no effect on the width of the beach.

10. Which of these correctly describes an ocean wave? a. longitudinal wave. b. orbital wave. c. transverse wave. d. polarized wave. e. seismic wave.

11. The type of surf that occurs on the very steepest shorelines is a: a. spilling surf. b. whitecap. c. plunging surf. d. curling surf. e. surging surf.

12. Dispersion of waves causes them to: a. break more rapidly as they approach a steep beach. b. bend so that they approach a coastline more parallel than when they were farther out at sea. c. get larger in height as they approach shallow water. d. separate into groups of the same wavelength wave, with the longest waves moving the fastest. e. move more rapidly as they approach shallow water.

13. In order for a surfer to move down the face of a wave as the board moves forward, what must the surfer do? a. cause all forces to add up to zero. b. increase the gravitational force. c. decrease the board’s buoyancy. d. increase friction on the board. e. decrease friction on the board.

14. Surf waves can be predicted through the use of: a. periodic comparisons from one storm to another. b. reports from coastlines to the north and south of the beaches of interest. c. reports from oceangoing ships on the size and speed of waves. d. satellite photos that show the direction and wavelength of waves. e. offshore buoys that measure the period and height of waves.

15. The reason that extremely large waves (50 ft + high) occur on the of at the location known as "Jaws" is that: a. refraction of waves over a submerged increases their size. b. they are funneled up a . c. the water is very deep in that location. d. the beach is extremely steep at that location. e. they form due to extreme tidal effects.

16. If you are at the beach, which of the following observations is likely to result in a low tide at your location, at the time you make your observation? a. The moon is directly overhead. b. The moon is rising from the eastern horizon. c. The Sun is directly overhead. d. The moon is full. e. The moon is half-full.

17. Which of these tidal types would you expect to see if you were in the Arctic? a. diurnal tide. b. neap tide. c. micro-tide. d. semidiurnal tide. e. tide. 2 18. The celestial body with the strongest influence on ocean tides is: a. the Moon. b. Jupiter. c. Mars. d. the Sun. e. In fact, the Sun and Moon have about equal influences.

19. From a practical point of view, the best way to predict tidal amplitudes and timing at a particular point on a coastline is: a. by analyzing a detailed map of depth and configuration of nearby shorelines, coupled with knowledge of the shape of the ocean basin. b. by determining the latitude of the coast compared to the moon. c. by looking at past records of tides. d. by using the predictive qualities of the amphidromic point. e. by determining where the moon and sun are in relation to the coast.

20. We would expect that, through geologic time, tidal friction on the Earth results in all of the below except: a. slowing down of the Earth's rotation. b. an increase in the length of the Earth's day through time. c. a decrease in the number of days in the Earth's year through time. d. increase in length of the Earth’s year. e. none of these are true.

21. In Figure 4, the features labeled 1, 2, 3, and 4 are, respectively: a. sea arch, , sea , sea . b. berm, beach scarp, foreshore, bar. c. sea stack, headland, , sea arch. d. sea stack, sea arch, sea cave, headland. e. baymouth bar, spit, barrier island, tombolo.

22. Which of these factors has the potential to affect global sea level rapidly (thousands of years) by up to 100-200 meters? a. tectonic uplift or subsidence of coastlines. b. changes in global erosion rates. c. changes in oceanic temperatures. d. changes in glaciation. e. changes in the rate of seafloor spreading.

23. The coastline shown in Figure 5 (a series of marine terraces) would be classified as: a. depositional. b. emergent. c. erosional. d. artificial. e. submergent.

24. Most sediment arrives at coastlines through what means? a. rivers. b. wind. c. landslides from faces. d. glaciers. e. waves.

25. are: a. smaller than normal low tides. b. submerged river valleys due to sea level rise. c. uplifted wave cut terraces in an . d. deep glacially carved valleys cutting into the . e. evidence of a depositional coastline.

26. Chesapeake (Figure 3) is: a. a former river valley that was flooded by a rise in sea level. b. associated with a submergent coast. c. an important nursery for marine life d. an excellent example of a large . e. all of these.

27. Which of these statements about tidal is false? a. Tidal inlets can appear or disappear in barrier . b. Tidal inlets can migrate along barrier islands. c. Tidal inlets can be stabilized with jetties with no ill effects. d. Tidal inlets store large amounts of sediment in tidal deltas. e. Old tidal inlets can be identified as low spots in barrier islands.

28. According to Orrin Pilkey (the narrator of the "Beaches are Moving" video), the inevitable result of building a groin is: a. the construction of a groin field. b. an overall thinning of beach width. c. the accumulation of coarser sand. d. the accumulation of finer sand. e. more common rip currents.

29. As sea level rises, barrier islands: a. tend to get washed away. b. tend to grow in altitude. c. tend to migrate away from shore. d. tend to stay put. e. tend to migrate towards shore. 3 30. During calm weather and moderate waves, the direction of sand transport at the beach is primarily: a. offshore. b. onshore. c. against the . d. towards the groins. e. downwards, compacting it.

Non-Multiple Choice. You MUST do #1. Including #1, you must do a total of seven and only seven of questions 1-12 (6 pts each). 1. For an ocean wave with the following characteristics, calculate the speed of the wave. You may find the equations on the first page of the exam useful. Wavelength = 25 meters, Water Depth = 100 meters, Wave Height = 4 meters. SHOW ALL OF YOUR WORK, INCLUDING HOW YOU DECIDED ON WHICH EQUATION TO USE. ------(Note: several lines available for this on the actual test) ------

2. As waves approach shore, they break in different ways that affect the type and duration of ride that surfers can get. Give the names and description of the 3 different types of breaking waves breaking on , and explain the processes and properties that cause these to occur. ------(Note: several lines available for this on the actual test) ------

3. Coastlines can be characterized as: emergent, submergent, depositional, and erosional. Discuss what each of these terms means in the context of coastlines, and give examples of coastlines or coastline features that would be classified as each of these, and explain how they formed. ------(Note: several lines available for this on the actual test) ------

4. What happens as a wave in very deep water approaches shallow water? At what point does it become a "shallow water wave", and what are the changes to the overall shape of the wave, to the measurable properties of the wave (such as wave speed, height, energy, wavelength, period, and direction), and to the motion of the water particles in the wave a. The wave becomes a shallow water wave when: ______b. The motion of the water particles in the wave changes from ______to ______c. The wave speed: decreases stays the same increases (circle correct answer) d. The wave height: decreases stays the same increases (circle correct answer) e. The wave energy: decreases stays the same increases (circle correct answer) f. The wave wavelength: decreases stays the same increases (circle correct answer) g. The wave period: decreases stays the same increases (circle correct answer) h. The wave direction: bends towards the shore stays the same bends away from shore. (circle correct ans.)

5. Matching: Coasts and Beaches ____ A. opening between barrier islands. ____ seawall B. transport of sand parallel to the shore. ____ estuary C. structure meant to block erosion of a beach. ____ tidal delta D. sand pushed into deep water by storm waves. ____ E. feature characteristic of submergent coastline. ____ offshore bar F. part of the beach that is accessible to the public. ____ barrier island G. placing any rigid materials on a beach to protect it. ____ hard stabilization H. linear, migrating, sand body above sea level, parallel to the shore. ____ recreational beach I. sand deposit resulting from flow through a barrier island opening. ____ longshore transport J. region of seagrass growth that protects the backside of barrier islands.

4 6. Match the observation with the type of tide you would expect. (Hint: draw the configuration of Earth, ocean, and astronomical bodies to see what this would do to the tide.) _____ sun is overhead. A. Cannot determine the tide from this information. _____ sun is on the horizon. B. High tide. _____ moon is overhead. C. Low tide. _____ moon is on the horizon. D. Spring tide. _____ moon is new. E. Neap tide _____ moon is half-full. (Note: some of these answers will be used more than once; _____ moon is full. all answers will be used at least once.)

7. To the right is a map of a headland sticking out into the ocean, with some waves (drawn as black lines representing the wave crests) approaching from the north. Draw continuing wave crests as the waves move in towards the coast and as they refract.

8. Discuss the forces on a surfboard that enable the surfer to stay on the face of a wave. What has to happen to these forces for him/her to stay there, and how does the surfer move up or down the wave face? What direction do the forces point in? A well-labeled drawing will probably be helpful. ------(Note: several lines available for this on the actual test) ------

9. What are the ways that sealevel at coastlines changes? Discuss these ways, including information about whether the changes are worldwide or local, how fast the changes can occur, and how much sealevel can change as a result. ------(Note: several lines available for this on the actual test) ------

10. In Figures 1 and 4 and the end of the exam there are a number of coastal features shown. Describe how features 1,2, and 3 in Figure 1 and features.1,3, and 4 in Figure 4 formed. To avoid confusion, do not use their names, only their numbers. How would you classify the coastlines in Figures 1 and 4, and why? ------(Note: several lines available for this on the actual test) ------

11. In the tide charts to the right, circle and label one example of each of the following: A. neap tide. B. mixed tide. C. spring tide. D. diurnal tide. E. semidiurnal tide. Note: In some cases, the answer is the whole chart; in other cases, the answer is part of one of the chart. Label them carefully!

5 12. Several structures were discussed in the video, "The Beaches are Moving" that were designed to make alterations in a coastline. These are represented in the map below as A, B, and C. Name each one and discuss what each one is designed to do, how it does it, and any problems this might cause.

Figure 1: Figure 2:

Figure 3: Figure 4:

Figure 5:

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