1 OCEANOGRAPHY 101 NAME____________________ EXAM 2 WINTER ‘00 STUDENT NUMBER___________ Map, and temperature, salinity & density profiles of the water column at X, near mouth of the Columbia River. P a WA c i f X i c Columbia R O c OR e a n HYPOTHETICAL DISASTER SCENARIO: An oil tanker broke up off the coast of Washington near the mouth of the Columbia River during Monday’s storm, and you have been called in to lend your expertise to the NOAA (National Oceanic & Atmospheric Administration) team that investigates such accidents. The oil tanker was carrying two types of oil: • CRUDE OIL which can be seen floating at the surface, and • BUNKER FUEL, which immediately sank to a depth of 100 meters and is spreading out at that level. 1. The water column at X is ___ with respect to density. a. stable b. unstable c. neutral d. not enough information to answer 2. Based on the depth to which the BUNKER FUEL sank, determine its sigma-t value (st). a. 10 b. 15 c. 20 d. 25 e. 100 3. What direction do you predict the CRUDE OIL at the sea surface will drift over the next several days? [NOTE: Assume normal winter conditions.] a. to the south, and on-shore (toward the land) c. to the north, and on-shore b. to the south, and off-shore (out to sea) d. to the north, and off-shore 4. Based on your knowledge of Ekman transport, do you predict the BUNKER FUEL will drift the same direction as the crude oil? a. Yes. It is within the Ekman layer, all of which moves the same direction. b. Yes. Although it is below the Ekman layer, movement of the Ekman layer will drag it along in the same direction. c. No. Although it’s in the Ekman layer, the deeper water will move in a different direction than the surface water. d. No. It is below the Ekman layer, so it will move the opposite direction. e. NO. It is below the Ekman layer, so the only thing that controls its movement is density. 5. Since it’s winter, ___ should be occurring right along the coast. a. upwelling b. downwelling 2 Questions __: Note the following locations & features: G East coast, N America, 45°N H Mediterranean J Current K Current L Current M Current N Mouth of Amazon River, 0° P Eastern equatorial Atlantic R Open ocean, 30°S S West coast, S. America, 55°S T West coast of Africa, 30°S U Open ocean, 45°S W Open ocean, 60°S 6. In eastern equatorial Atlantic (P) you would find a. high salinity c. frequent hurricanes b. upwelling of cold water d. higher sealevel than at N 7. To the east of point H in the Mediterranean you'd expect to find ___ productivity due to ___ a. low / downwelling b. low / upwelling c. high / downwelling d. high / upwelling 8. Arrange locations H, N, P, R in order from the lowest salinity to the highest salinity. a. H, N, P, R b. N, R, P, H c. H, N, R, P d. N, P, R, H 9. Of the following currents, which is strongest, fastest and most intense? a. J b. K c. L d. M 10. Copepods, are small floating animals that live in surface seawater. One of these comes from location N and one from W. Assume that the overall body weight of these two copepods is the same. Comparing body form, Copepod 1 most likely lives at __; the frilly appendages are adaptations that __. Picture missing; copepod1 is has frilly appendages; 2 has simpler, sleeker lines a. W / keep it warm in the colder water at W. b. W / help it float in the water at W, which has a higher density than at N. c. N / help it actively swim in the water at N, which is more viscous than at W d. N/ help it float in water at N, which is less viscous and less dense than the water at W. 11. Considering locations P, R, T & W, where does convergence occur in the surface water? a. Only at P d. R in the summer & W in the winter b. At R all year, & at T in the winter e. P, R & W, all year c. At W all year, & at T in the summer 12. The photic zone a. reaches greater at R than at N b. is the zone in which respiration proceeds faster than photosynthesis c. becomes deeper when there is a big wind storm like the one we had last week. d. is the same thing as the pycnocline e. all of the above 13. In each of the ocean basins on the map, there are four currents that flow around that basin, forming an oceanographic feature known as a ___. a. cyclone b. hydrologic cycle c. eddy d. gyre e. Ekman spiral 3 14. Coriolis Effect forces water into a “hump”, more or less in the middle of each ocean basin, but is countered by the force of gravity which pulls the water down hill. When these two forces are in balance, the flow of water that is established is known as a. thermohaline circulation d. centrifugal force b. pycnocline e. convection c. geostrophic flow 15. Which of the following results in an increase of nutrients in surface seawater? a. increasing sea surface temperature b. the motion of Antarctic Bottom Water through the Atlantic Ocean c. formation of Mediterranean Water d. heavy precipitation directly into the ocean at the equator e.the motion of North Atlantic Deep Water in the vicinity of the Antarctic Divergence 16. Suppose a huge dam was built on the Amazon River in order to generate electricity and control floods. Which of the following would likely occur as a result of the dam construction? a. increased the biological productivity at the mouth of the river d. all of the above b. increase in the nutrient concentration at the mouth of the river e. none of the above c. increased salinity at the mouth of the river 17. According to Dr. Wally Broecker in the video The Big Chill, the North Atlantic Conveyor a. is strongest when there is NO formation of the watermass North Atlantic Deep Water b. shuts “off” when ice covers North America during major ice ages c. promotes the flow of warm water into high latitudes to warm England and northern Europe when it is “on” d. is a combination of the thermohaline circulation and Ekman transport in the North Atlantic e. c & d 18. At location R on the map on the previous page, the water column has the temperature and salinity profiles shown to the right. Which surface process could account for these profiles? a. freezing of sea water c. melting of glaciers b. evaporation d. precipitation 19. The water column shown in these profiles is ___. a. stable b. unstable c. neutral d. not enough information to answer 20. Which of the following is NOT a western boundary current? a. Agulhas b. Brazil c. California d. Gulf Stream e. Kuroshio 21. The warmer the water is, the ___ a. more gases will dissolve in it d. a & b b. more salts will dissolve in it e. b & c c. faster chemical reactions proceed in it 22. What is produced by the process of photosynthesis? a. light d. a & b b. food, in the form of sugars and carbohydrates (organic matter) e. b & c c. oxygen 23. Carbon dioxide a. is taken up by plants during photosynthesis and released during decay. d. a & b b. absorbs infrared radiation, which warms up the atmosphere e. a, b & c c. is less abundant in the deep ocean than in the surface water 24. Which of the following is a density driven phenomenon? a. thermohaline circulation d. all of the above b. hurricane e. none of the above c. atmospheric circulation 4 Imagine that you have won the lottery and manage to buy a large, mountainous, tropical island. Unfortunately, the agent who sells you the island neglects to tell you basic things about it, including where it is. You receive the map to the right, which shows the outline of the island and the prevailing winds that blow across the region all year, along with a note that says that the seawater on the southwest side of the island is quite cold, compared to the water on all the other sides (ah, yes… upwelling!). The following 5 questions refer to this island. 25. With upwelling of cold water on the southwest side, you would expect ___ to be greater there than on the other three sides of the island. a. abundance of plankton b. clarity of the water c. gas solubility d. a & b e. a & c 26. Based on the direction of the prevailing winds and location of the upwelling, you can conclude that your island is in the _____ hemisphere. a. northern b. southern c. eastern d. western 27. The proper name of this band of prevailing (“ideal”) winds would be the a. Easterlies b. Westerlies c. Tradewinds d. Doldrums e. Horse Winds 28. As the winds blow over the island, the air rises up to go over the mountain. The air will undergo adiabatic ___, resulting in ___ that will make the southeast side of the island ___ than the northwest side. a. cooling / evaporation / drier c. warming / evaporation / drier b. cooling / precipitation / wetter d. warming / precipitation / wetter 29. Consider two fish, both of which have internal body fluids with a salinity of 25 ‰.