Chapter 14: The Ocean FloorMultiple Choice 1. Which one of the following is NOT part of a passive continental margin? a. continental shelf b. continental slope c. continental rise d. continental trench 2. Atolls may be described as __________. a. coral reefs paralleling a nearby coast b. coral reefs surrounding a lagoon c. a flat-topped submergent seamount d. coral reefs separated from the mainland by a shallow lagoon e. a small reef growth in a lagoon 3. Which of the following would NOT be associated with turbidity currents? a. deposits of graded beds b. density current c. excavation of submarine canyons d. formation of seamounts e. sediment transport 4. Submarine canyons found on the continental slope and rise are believed to have been created ___________. a. by rivers during the ice age b. by faulting c. because of a plate plunging into the mantle d. any two of the above e. none of the above 5. Graded bedding is characterized by ___________. a. an increase in sediment size from bottom to top b. a decrease in sediment size from bottom to top c. an unsorted mixture of many different sediment sizes d. being found only on the continental slope off the Newfoundland coast 6. Which of the following is NOT true of deep ocean trenches? a. b. c. d. they are long and narrow depressions they are sites where plates plunge back into the mantle they are geologically very stable they may act as sediment traps 7. The best definition of the outer edge of the continental shelf is that place where __________. a. the gradient becomes very gentle b. the water depth reaches 100 fathoms c. it meets an oceanic ridge d. a rapid steepening of the gradient occurs e. none of the above 8. Seamounts ___________. a. are a special type of oceanic trench b. are volcanoes that form on the ocean floor c. form only in the Pacific Ocean basin d. are submarine canyons found near Australia e. none of the above 9. Which one of the following is NOT a requirement for coral reef growth? a. warm water b. shallow water c. abundant sunlight d. abundant amounts of suspended sediment 10. The scientist who correctly proposed the theory of atoll formation was _________. a. Kelvin b. Hutton c. Darwin d. Wegener e. none of the above 11. Which of the following is associated with mid-ocean ridges? a. rift zones b. mountainous topography c. greater heat flow than occurs in other parts of the world 70 these organisms kept pace by building the reef complex upward 12. turbidity currents e. Directly seaward of the continental shelf is a more steeply sloping region known as the __________. and hydrogenous sediment 13. sunlight water could create reef complexes extending for thousands of meters below sea level. a. terrigenous sediment b. a. biogenous sediment c. and hydrogenous sediment 14. a. biogenous sediment c. Minerals that crystallize directly from seawater are examples of ___________. Darwin hypothesized that __________. biogenous sediment. continental shelf b. continental shelf b. continental slope c. a. continental rise d. Charles Darwin was first to explain how reef-building organisms that require shallow. as sea level dropped during the onset of the ice age. submarine canyon e. in contrast to modern forms. hydrogenous sediment d. and hydrogenous sediment 15. in fact. both terrigenous sediment and biogenous sediment e. streams when sea level was much lower than it is today b. continental rise d. terrigenous sediment. live in deep. hydrogenous sediment d. both terrigenous sediment and biogenous sediment e. these organisms kept pace by building the reef complex upward c. and hydrogenous sediment 16. The gently sloping submerged surface extending from the shoreline toward the deep ocean is termed the __________. biogenous sediment. Manganese nodules are an example of ____________. terrigenous sediment. continental slope c. a. terrigenous sediment b. Calcareous ooze is an example of __________. faulting 20. both terrigenous sediment and biogenous sediment e. biogenous sediment. streams when sea level was much lower than it is today c. Most available information favors the view that submarine canyons on the continental slope have been generated by _________. a. as volcanic islands with fringing coral reefs began to sink. submarine canyon e. a. biogenous sediment. Located within the continental margin are deep. ocean basin 19. ocean basin 71 . terrigenous sediment b. terrigenous sediment. continental rise d. volcanic structures all of the above 17. terrigenous sediment b. these organisms built the reef in what is presently much deeper water d. both terrigenous sediment and biogenous sediment e. biogenous sediment c. hydrogenous sediment d. continental shelf b. cold. ocean basin 18. hydrogenous sediment d. steep-sided valleys known as __________. terrigenous sediment. biogenous sediment c. a. ancient reef-building organisms could. Sediments derived primarily from the products on the continents are called ___________. continental slope c. water b. as sea level rose during the Pleistocene. e. submarine canyon e.The Ocean Floor d. submarine glaciation d. a. a. The development of this instrument greatly enhanced our knowledge of the ocean floor. contain active rift zones d. have never been observed by humans 22. Atlantic b. The crests of mid-oceanic ridges _______. SS Trinity b. they deposit sediment that forms a(n) __________. 30 b. a. deep-sea fan c. submarine transit d. Alvin c. The continents cover approximately _____ percent of Earth’s surface. Arctic e. Challenger d. Indian 29. 32. Arctic c. d. a.k 21. a. none of the above Most deep-ocean trenches are located in the __________ Ocean. 50 d. The _________ Ocean is the largest ocean. Which ocean has the greatest average depth? a. titled. Indian d. are heavily mantled with sediment b. infrared opscanner 24. 50 Testban c. One of the deep-diving manned submersibles that has been used to photograph mid-ocean ridges is the __________. Atlantic b. Pacific c. Maury e. Indian d. Franklin c. the Northern Hemisphere has much more water surface than the Southern Hemisphere When muddy currents emerge from the mouth of a submarine canyon onto the flat ocean floor. 30 b. Artic e. pulsar b. 72 . Pacific 31. echo sounder c. Meteor d. a. Forbes d. 30. Fram c. which of the following statements is true? a. atoll d. The oceans cover approximately ______ percent of Earth’s surface. All are approximately the same size 28. a. the Southern Hemispheres has much more water surface than the Northern Hemisphere c. The Physical Geography of the Sea. a. lie at depths exceeding 6 kilometers c. 40 c. 70 25. the percentage of land and water is about the same in both the Northern and Southern Hemispheres b. 70 26. Challenger b. a. tuzometer e. 60 e. Alvin e. 60 e. a. are geologically old features e. Thomson The first and perhaps most comprehensive study of the global ocean lasted from December 1872 until May 1876 and is known as the __________ expedition. Maury Concerning the distribution of land and water. Atlantic b. Nansen b. alluvial fan b. 40 c. He wrote the first textbook on oceanography. Catanach 23. SS Woods Hole e. All are approximately the same size 27. slope fan e. a. Most deep-ocean trenches are located in the Pacific. 44. The mid-ocean ridges stand above the deep ocean basin mainly because they are warmer. the mid-oceanic ridge actually extends above sea level.” 46. Abyssal plains are more extensive on the floor of the Atlantic as compared to the floor of the Pacific. and thus more buoyant than adjacent regions. The average height of the continents above sea level is greater than the average depth of the oceans below sea level. 45. The Northern Hemisphere is sometimes called the “land hemisphere.000 kilometers on the ocean floor and is known as the __________.. 34. In a few locations such as Iceland. 40.000 feet). 41. Turbidites are examples of biogenous sediment. Oceanic ridges exist only in the Atlantic and Pacific. 42. The largest ocean is the Atlantic. The continental margin off of the west coast of South America is very similar to the continental margin off of the east coast of North America.The Ocean Floor True-False: 33. Atolls are coral reefs surrounding a lagoon. 38. 49. The percentage of surface area in the Southern Hemisphere that is ocean. d. 43. 48. 39. is greater than in the Northern Hemisphere. A flat-topped seamount is termed a guyot. 36.” 47. 73 . The Southern Hemisphere is sometimes called the “water hemisphere. 35. Calcareous shells will not accumulate on the ocean floor when the water depth exceeds about 4500 meters (15. The deepest portions of the ocean are part of the relatively narrow features called submarine canyons. 37. Pacific Completion: 50. The most extensive mountain range on Earth extends for about 65. The area covered by oceans is greater in the Northern Hemisphere than the Southern Hemisphere. 54 The gently sloping submerged surface extending from the shoreline toward the deep ocean is termed the __________. and rise make up a unit called the continental __________. 55. 53. 59. The correct theory of atoll formation was proposed by __________.k Testban 51. The ocean floors are dotted with isolated volcanic peaks called __________. Manganese nodules are an example of __________sediment. 52. The first and perhaps most comprehensive study of the global ocean lasted from December 1872 until May 1876 and is known as the __________ expedition. 74 . 58. 61. The two main types of continental margins are __________ and __________. 56. Flat-toped volcanic structures located on the floor of the deep ocean basin are termed __________. slope. 60. Name the instrument used to measure water depths in the ocean by employing sound waves. The continental shelf. 57. A prominent feature of the Mid-Atlantic is a very deep linear valley known as a __________ valley. __________ sediment consists of shells and hard parts of marine organisms. 36. 6. 8. 47. 26. 38. a b b d a b 31. d b d c e b 13. 24. 28. 10. 3. active continental margins 75 . 54. 4. 42. a c c a b d 19. 20. 40. 58. 51. 45. 23. 2. 11. d True-False: 33. 29. 46. 61. 21. 59. 5. 41. 55. 53. 15. mid-ocean ridge guyot rift Charles Darwin continental shelf margin Biogenous hydrogenous seamounts echo sounder Challenger passive continental margins. 39. 30. 14. 9. 17. d b d e b c 7. 52. 43.The Ocean Floor Answers to Chapter 14 Test Questions Multiple Choice: 1. 22. true true true false false false Completion: 50. 34. 48. 49. 35. 27. b 32. d d c b d e 25. 57. 56. false true true false false true true true true true false 44. 16. 60. 37. 12. 18.