Exam 1

Name: . SCG120: Introduction to Oceanography March 27, 2017 Exam #1 Each answer is worth 2.38pts. Directions : Circle the letter next to the response that best answers each question. 1. The largest and deepest of the ocean basins, which currently covers more than half of the ocean surface, is the ________. a. Arctic Ocean b. Atlantic Ocean c. Indian Ocean d. Pacific Ocean e. Southern Ocean 2. Which ocean is similar in size and average depth to the Indian Ocean? a. Arctic Ocean b. Atlantic Ocean c. Indian Ocean d. Pacific Ocean e. Southern Ocean 3. Which ocean is the shallowest ocean on Earth? a. Arctic Ocean b. Atlantic Ocean c. Indian Ocean d. Pacific Ocean e. Southern Ocean 4. What is the difference between a sea and an ocean? a. Seas are partly enclosed by land whereas oceans are not b. Seas are composed of fresh water whereas oceans are salty c. Seas smaller in area and shallower in average depth d. a & c only e. a, b, & c 5. Plate tectonics and evolution, which are held with a high degree of confidence because of repeated rigorous testing and verification, are examples of ________. a. truths b. observations c. hypotheses d. theories e. guesses 6. The nebular hypothesis suggests that ________. a. all bodies in the solar system formed from an enormous cloud of gas and dust b. Earth's moon is a planet captured by the Earth's gravity c. galaxies such as the Milky Way form independent of one another d. thermonuclear fusion occurs within the Sun’s core

7. The separation of the Earth into layers while it was molten was a result of the ________. a. decrease in temperature downward toward the core b. differing densities of the elements that make up the Earth c. presence of water at Earth's surface d. none of the above 8. Which of the following statements regarding continental and oceanic crust is TRUE? a. Continental crust and oceanic crust have equivalent densities. b. Continental crust is thicker and denser than oceanic crust. c. Continental crust is thinner and denser than oceanic crust. d. Continental crust is thicker and less dense than oceanic crust. 9. Isostatic adjustments are the result of the buoyancy of Earth's lithosphere as it floats on the ________ below which is denser and plastic like. a. asthenosphere b. mesosphere c. outer core d. inner core 10. Stanley Miller's 1952 experiment created ________ from the chemical ingredients and simulated environmental conditions thought to exist in Earth's early ocean. a. simple organic compounds b. animals c. boulders d. plants e. bacteria 11. Heterotrophs and autotrophs are linked on Earth by the processes of cellular respiration and photosynthesis, respectively. Why is that? a. Heterotrophs make nutrients and autotrophs use them. b. Autotrophs produce carbon dioxide and heterotrophs produce oxygen. c. The end products of photosynthesis are the starting products for respiration and vice versa. d. The waste products of heterotrophs are utilized by other heterotrophs for respiration. e. All of the above are true. 12. Comparing the amounts of ______________ and _________________ in rocks helps determine their age. a. granite, basalt b. radioactive material, decay product c. thermonuclear fusion, ions d. nickel, iron 13. Which of the following is used as evidence for continental drift? a. Geographically dispersed modern organisms with similar ancestries. b. The true edges of modern continents have a puzzle like fit. c. Evidence of past glacial activity in presently tropical regions. d. Sequences of mountain chains and the types, ages, and structures of rocks are matching on continents separated by an ocean. e. All of the above. 14. As Earth rotates, strong electrical currents are generated in the liquid iron ___________, creating Earth’s magnetic field. a. asthenosphere b. mesosphere c. outer core d. inner core

24. Unlike __________, ____________ reach above sea level and have their tops eroded flat by wave activity. a. tablemounts, seamounts b. seamounts, sea knolls c. guyots, tablemounts d. seamounts, tablemounts 25. Coral reefs ________. a. are most common in cold sub-tropical basins b. are most common in deep water c. include atolls, barrier, and fringing reefs d. None of the above 26. Satellites are used to map the ocean floor because ________. a. they are inefficient b. they can only "see" small areas of the seafloor at one time c. the shape of the ocean surface mimics the shape of the seafloor d. None of the above 27. Active continental margins are characterized by which of the following? a. Wide continental shelves b. Deep-sea trenches c. No earthquake activity d. None of the above 28. Characteristics of passive continental margins include which of the following? a. Wide continental shelves b. Deep-sea trenches c. Volcanic and earthquake activity d. Nemataths 29. Which continental margin feature is unique to passive margins? a. continental shelf b. shelf break c. mid-ocean ridge d. continental rise 30. Underwater avalanches of muddy water mixed with rocks and debris are ________. a. turbidity currents b. coral deposits c. white smokers d. suspension settling 31. The continental rise is comprised of many ___________________ containing graded bedding. a. abyssal hills b. deep sea fans c. coral deposits d. igneous rocks 32. Extending from the base of the continental rises into the deep-ocean basins are flat depositional surfaces called ________. a. continental shelves b. continental slopes c. abyssal hills d. tablemounts e. abyssal plains

33. Relatively few abyssal plains are located in the Pacific Ocean due to ________. a. its smaller size compared to other ocean basins b. the presence of convergent active margins c. the presence of seamounts d. its location in northern and southern hemispheres e. the presence of divergent active margins 34. Why is the margin of the Pacific Ocean called the “Ring of Fire”? a. The Pacific Plate borders many convergent boundaries around the rim, which has active volcanoes and earthquakes . b. The Pacific Plate is getting larger and is surrounded by ridges. c. Hotspots surround the Pacific Plate. d. The “Ring of Fire” is folklore, and the rate of earthquakes is the same everywhere. e. None of the above. 35. At mid-ocean ridges, seamounts and pillow lavas (basalt) are found. What is the difference between these structures? a. Seamounts are found at convergent boundaries while pillow lavas are found at divergent boundaries. b. Pillow basalts form when hot lava from the sea floor is cooled quickly by cold seawater, creating smooth, rounded lobes. A seamount is an underwater volcano. c. Seamounts are flat topped while pillow lavas are rounded. d. Pillow lavas are formed at continental arcs, while seamounts are formed at island arcs. 36. Why does hot water come out of hydrothermal vents on the flanks of the mid-ocean ridges? a. Water is released from the mid-ocean ridge magma and condenses out of the crust. b. Flows of hot lava on the sea floor cause seawater to be heated. c. Seawater percolates down through cracks in the crust, is heated in the hot deeper crust, and rises back up to the surface through other cracks. d. Chemical reactions result in dehydration of the crust when fresh water is in contact with fresh basalt near the mid- ocean ridge. 37. How are oceanic islands formed? a. Hotspots form island chains as the overlying tectonic plate moves. b. Island arcs from at oceanic-oceanic convergent boundaries. c. Mid-ocean ridges form undersea volcanoes, which breach the surface of the ocean. d. a & b e. All of the above. 38. The correct order of seafloor features from the coast to the mid-ocean ridge is ________. a. abyssal plain, rise, slope, shelf b. abyssal plain, shelf, slope, rise c. rise, abyssal plain, slope, shelf d. shelf, slope, rise, abyssal plain 39. What is a linear sea floor feature that is seismically active , occurs between offset mid-ocean ridge segments, and the relative movement between two points on either side of the feature is in the opposite direction? a. Fracture zone b. Guyot c. Nematath d. Transform fault

42. Fill in the name of each ocean and continent in the following figure of Earth: Extra Credit Fill in the blank. Oceanic crust is composed of dense __ Basalt ___ and continental crust is composed of more buoyant ______ Granitic rocks____. Indian Asia Austalia Antarctica Arctic Ocean North America Pacific South Atlantic Ocean Asia Africa Europe