OCE1001, INTRODUCTION TO OCEANOGRAPHY, Fall, 2016 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: (8 pts) Do not put these on the scantron sheet. 1. ____ amphidromic A. disturbance of wave is parallel to wave movement. 2. ____ bore B. opening under an eroded headland. 3. ____ eustatic C. part of the beach that is accessible to the public. 4. ____ longitudinal D. point where the tide neither rises nor falls. 5. ____ sea cave E. submerged area of coast eroded flat by waves. 6. ____ recreational beach F. tide rises suddenly as one or a few waves come up a river. 7. ____ transverse G. wave having motion at right angles to the direction of wave movement. 8. ____ wavecut terrace H. worldwide change in sea level. Multiple Choice: (2 pts each) Put the answers to these questions on the scantron sheet. 1. A wave in which the height is 2 meters, the wavelength is 600 m, and the water depth is 150 m would be considered to be a: a. deep water wave. b. plunging breaker. c. spilling breaker. d. tsunami. e. shallow water wave. 2. Which of these factors is not necessary to form large wind waves? a. all of these are necessary. b. high wind speed. c. great water depths. d. long wind duration. e. long fetch. 3. Your best strategy if you are caught in a RIP CURRENT is to: a. accept inevitable death. b. swim back to shore directly against the current. c. swim with the current until it reverses and takes you back to shore. d. swim parallel with the shore until out of the current, then swim back to shore. e. float with the rip current until it stops, and catch another rip current back to shore. 4. The process that bends waves as they approach shallow water is: a. refraction. b. diffraction. c. reflection. d. infraction. e. deletion. 5. If waves are approaching a groin from the southwest (Figure 1), 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. wider, wider b. the waves will have no effect on the width of the beach. c. narrower, narrower d. wider, narrower e. narrower, wider 6. In Figure 2, the features labeled C, O, A, S, and T are, respectively: a. baymouth bar, hook, tombolo, spit, barrier island. b. hook, tombolo, spit, barrier island, baymouth bar. c. tombolo, spit, barrier island, baymouth bar, hook. d. spit, barrier island, baymouth bar, hook, tombolo. e. barrier island, baymouth bar, hook, tombolo, spit. 1 7. The factor that is most important in controlling the speed of a wave in "shallow" water is the: a. height of the wave. b. salinity of the water. c. depth of the water. d. steepness of the wave. e. wavelength of the wave. 8. The most important cause worldwide of waves, in terms of total energy, is: a. meteorites. b. winds. c. earthquakes. d. tides. e. none of these. 9. If we follow the motion of water in a deep 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. in an elliptical path in deep water only. d. in circles, with the size of the circles increasing as depth increases. e. in circles, with the size of the circles decreasing as depth increases. 10. 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 name for the motion of a particle of water in a water wave. d. the depth to which waves can "feel" the ocean bottom. e. the time it takes for an identical point on two successive waves to pass a given point. 11. In a "fully developed sea", the waves will be moving: a. as capillary waves. b. as surging surf. c. slower than the wind. d. faster than the wind. e. at the same speed as the wind. 12. A DEEP WATER wave BREAKS when: a. the water depth decreases to 1/2 of the wavelength. b. the windspeed exceeds the wavespeed. c. the height exceeds 1/7th of the wavelength. d. the height exceeds 0.8 of the depth. e. the height exceeds 10 m. 13. SPILLING WAVES occur near the beach instead of PLUNGING OR SURGING WAVES when: a. the beach is steep. b. the beach is not very steep. c. the beach is composed of fine sand. d. the waves are smaller. e. the wind is blowing out to sea. 14. The reason that extremely large waves (50 ft + high) occur on the coast of Hawaii at the location known as "Jaws" is that: a. they form due to extreme tidal effects. b. refraction of waves over a submerged reef increases their size. c. they are funneled up a river mouth. d. the water is very deep in that location. e. the beach is extremely steep at that location. 15. The separation of ocean waves emanating from a storm center into groups of approximately constant wavelength and period is called: a. dispersion. b. refraction. c. reflection. d. separation. e. distinction. 16. Which of the orbital configurations shown in Figure 3 would result in a NEAP tide? The letters m,n,o,p,q,r,s,t are possible positions of the Moon orbiting Earth. a. o and s. b. n only. c. p and t. d. m and q. e. n and r. 17. If you are at the beach, which of the following observations is likely to result in a high 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 moon is setting into the western horizon d. The moon is full. e. The moon is half-full. 18. The celestial body with the strongest influence on ocean tides is: a. the Sun. b. Jupiter. c. Mars. d. the Moon. e. In fact, the Sun and Moon have about equal influences 2 19. 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. fewer daily growth bands on fossil shells today than in the past. e. a longer time for the Earth to orbit the sun today than in the Earth's past history. 20. The length of a Tidal Day is about: a. 12 hours. b. 12 hours and 25 minutes. c. 24 hours. d. 24 hours and 50 minutes. e. 28 days. 21. The primary source of sand at most coastlines is: a. biogenic activity. b. glacial transport. c. rivers. d. windborne dust. e. waves pushing up sand from very deep water. 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 glaciation. d. changes in oceanic temperatures. e. changes in the rate of seafloor spreading. 23. In Figure 4, the features labeled 1, 2, 3, and 4 are, respectively: a. sea arch, headland, sea stack, sea cave. b. sea stack, headland, sea cave, sea arch. c. berm, beach scarp, foreshore, sand bar. d. sea stack, sea arch, sea cave, headland. e. baymouth bar, spit, barrier island, tombolo. 24. Which of these features would indicate the presence of an emergent coastline? a. a fjord. b. a baymouth bar. c. extensive sedimentation. d. an elevated beach terrace. e. an estuary. 25. Which of the following factors contributing to the development of a coastline is most important? a. All of these are equally important. b. Original Geology of the coastline. c. Tides and Currents. d. changes in Sea Level. e. the amount of Wave Action. 26. "New Jersey-ization" refers to: a. filling bays with landfill to produce new real estate. b. hard stabilization all along the coast, with the resultant destruction of the beach. c. the gradual pollution of all marine environments. d. building condominiums into the sea. e. the continual replenishment of beaches with offshore mud. 27. Why are salt marsh mud and oyster shells found on seaward sides of Barrier Islands today? a. They were originally deposited on the sides closest to the mainland and the Barrier Islands migrated landwards over them. b. They were originally deposited there. c. They were transported there by longshore drift. d. They were dumped there during dredging of salt marshes. e. They were blown there by strong winds at the end of the last glaciation. 28. A predictable outcome of building a seawall to protect a shore building is: a. decreased rates of local sea level rise.