DYNAMIC PLANETEASTSIDE INVITATIONAL 2017

1. Continents a. plow their way through the sea floor.b. passively ride along as the sea floor spreads.c. may subduct if they are old and dense enough.d. consist of rock that is younger than sea-floor rock.e. have retained the same size and shape throughout earth’s history.

2. Which statement is FALSE?a. As the sea floor spreads, the asthenosphere rises, melts to become magma, and fills the space between plates.b. Some magma generated during sea-floor spreading spills out to produce a new layer of sea floor called gabbro.c. Some magma generated during sea-floor spreading erupts from submarine volcanoes.d. Observers in the research submarine, the Alvin, have seen submarine volcanoese. The sea floor is made of basalt.

3. Major earthquakes and volcanic eruptionsa. do not occur at similar locations.b. usually occur on the boundaries of plates or at hot spots.c. usually occur at the center of plates.d. prove through their locations that Earth is splitting apart at all plate boundaries.e. occur at divergent plate boundaries and hot spots only.

4. The chain of volcanoes along the west coast of South America (the Andes Mountains) exist becausea. the Pacific Plate is sliding past the South American Plate and heading toward the northwest.b. the Pacific Plate is rifting apart from the South American Plate.c. an oceanic plate is subducting under the western edge of the South American Plate.d. a continental plate is colliding with the South American Plate and causing it to buckle.e. basalt is pushing up through the trench that parallels the west coast of South America.

5. Pick out the FALSE statement. According to present plate tectonics theory,a. plates move on the asthenosphere.b. plates move at speeds of a few centimeters per year.c. a continental plate will subduct under an oceanic plate when the two converge.d. plates are composed of the crust and the uppermost part of the mantle.e. all continental material started out as one supercontinent called Pangaea.

6. The huge trough down the center of the mid-ocean ridge is wherea. molten basalt subducts back into Earth.b. the actual plate boundary is located.c. the Hawaiian Island chain formed.d. two continental plates converge.e. you find the oldest, densest, hottest oceanic crust.

7. Both earthquakes and volcanoes occur in Alaska becausea. two plates are moving past each other there.b. a continental plate is colliding with another continental plate there.c. an oceanic plate is converging with a continental plate and subducting there.d. two plates are diverging there.

8. Earthquakes, but not volcanoes, occur in San Francisco becausea. two plates are moving past each other there.b. a continental plate is colliding with another continental plate there.c. an oceanic plate is converging with a continental plate and subducting there.d. two plates are diverging there.

9. The Himalayas are growing becausea. two plates are moving past each other there.b. a continental plate is colliding with another continental plate there.c. an oceanic plate is converging with a continental plate and subducting there.d. two plates are diverging there.

10. Pick out the FALSE statement. A subducting platea. can be either continental or oceanic lithosphere.b. has a trench along its seaward edge.c. can be charted by noting its Wadati-Benioff zone.d. has a volcanic arc associated with it.e. has an accretionary prism assocated with it.

11. Asthenospherea. is warm enough to flow slowly.b. subducts when it collides with continental lithosphere.c. is the lower layer of both continental and oceanic lithosphere.d. is the uppermost layer of Earth’s core.e. contains the Wadati-Benioff zone where submarine quakes originate.

12. The rate of plate motiona. can be determined to within millimeters by using the Global Positioning System.b. is faster along the northern Mid-Atlantic Ridge than along the East Pacific Rise.c. was first correctly determined by J. Tuzo Wilson in the 1960s.d. changes about every 1,000 years.e. All of the above are true.

13. Pick out the FALSE statement.a. When an oceanic plate subducts under another oceanic plate, a volcanic island arc is formed.b. Oceanic lithosphere gets no older than 200 million years.c. All oceanic lithosphere eventually subducts into the mantle and probably melts there.d. Iceland will eventually split apart because it sits astride a diverging plate boundary.e. Hawaii is a volcano because it is located on a convergent plate boundary.

For questions 14 – 20, examine the profile of the ocean floor in the diagram above. Choose the correct label for each part of the diagram.

14. a. Guyot b. Abyssal plain c. Volcanic arc d. Mid-ocean ridge e. Seamount

15. a. Abyssal plain b. Mid-ocean ridge c. Trench d. Seamount e. Guyot

16. a. Volcanic arc b. Seamount c. Guyot d. Trench e. Oceanic

island

17. a. Seamount b. Volcanic arc c. Mid-ocean ridge d. Oceanic island e. Guyot

18. a. Seamount b. Oceanic island c. Abyssal plain d. Volcanic arc e. Mid-ocean ridge

14 15 16 17 18 19 20

19. a. Trench b. Mid-ocean ridge c. Seamount d. Oceanic island e. Abyssal plain

20. a. Guyot b. Abyssal plain c. Oceanic island d. Trench e Volcanic arc

21. Only one supercontinent has broken up during Earth’s history.a. Trueb. False

22. The Alps, Himalayas, and Appalachians are all the results of collision.a. Trueb. False

23. Crust beneath mountains can be twice the thickness of normal continental crust.a. Trueb. False

24. There is convective flow (with hotter rock rising, cooler sinking) within the asthenosphere.a. Trueb. False

25. Earthquakes typically occur along passive continental margins.a. Trueb. False

26. Hot spots result when columns of especially hot material move slowly beneath plates.a. Trueb. False

27. Hot spots may occur under land, as illustrated by Yellowstone, or under the sea floor, as illustrated by Hawaii.a. Trueb. False

28. All islands along a hot-spot chain remain volcanically active for the lifetime of the mantle plume involved.a. Trueb. False

29. The San Andreas Fault is a long, narrow valley from which lava often oozes onto the surface.a. Trueb. False

30. Slab-pull and ridge-push are the two processes that cause sea-floor spreading.a. Trueb. False

For questions 31-35 , choose from the following list of scientists and match them to their contributions.

a. Robert Dietzb. Arthur Holmesc. Lawrence Morley

d. Harry Hesse. Alfred Wegener

31. ___ e _____ The developer of the continental drift hypothesis between 1915 and 1930

32. __ d ______ The Princeton professor who, in 1962, published ideas about how new ocean floor forms and causes the sea

floor to widen.

33. __ b ______ The British geoscientist who, in the 1930s, believed that giant convection cells carried hot rock from deep in

Earth up toward the surface.

34. __ a ______ The scientist who, in 1961, coined the phrase “sea-floor” spreading.

35. _ c _______ The Canadian geologist who, working independently in the 1960s, also correctly interpreted the significance

of marine magnetic anomalies.

Each letter in the block diagram represents a geologic event.

Use the diagram to answer the following questions

36. Which event is the oldest?a. Lb. Gc. Ad. Me. S

37. Which event is the youngest?a. Cb. Jc. Dd. Ae. M

38. Of the following, which event occurred first?a. Db. Sc. Ld. Pe. B

39. Plate tectonics theory took decades to be accepted becausea. most of Wegener’s ideas turned out to be wrong.b. of pure stubbornness by the scientific community.c. Wegener offered only some of the needed evidence.d. climate, fossil distributions, and land shape offered conflicting evidence.e. communications were bad, so only German scientists were familiar with Wegener’s theory.

40. Choose the FALSE statement. Pangaeaa. means “all land”.b. started to break apart during the Mesozoic.c. broke apart due to centrifugal forces.d. is the name for the most recent supercontinent; others have existed.e. is Wegener’s name for the supercontinent that split to produce our continents of today.

41. Which is NOT one of the ideas Wegener offered to support his theory:a. the good fit of the outline of the continents.b. the matching of the distribution of similar fossils across oceans.c. the existence of the mid-ocean ridge, where sea-floor spreading starts.d. paleoclimatic evidence of extreme climate chanes in some areas.e. the matching of similar rock types and structures across oceans.

42. Cygnathus, Glossopteris, Mesosaurus, and Lystrosaurus area. the names of the most recent periods of magnetic reversal.b. land-dwelling species whose distribution suggested joined continents.c. names of supercontinents that existed before Pangaea.d. distinctive assemblages of rocks.e. scientists who supported Wegener’s proposals.

43. Choose the FALSE statement. Glaciersa. are slow-moving sheets of ice on land.b. leave deposits of sediment called bathymetries.c. covered large areas of continents during ice ages.d. occurred during the late Paleozoic in places they cannot exist today.e. occur today at high altitudes or in polar regions.

44. Choose the FALSE statement. Magnetic anomalies area. places where the magnetic field strength is either greater or less than normal.b. normal if the atomic dipoles of local rocks match Earth’s current north pole.c. found both on land and in the sea floor.d. recorded in basalt only while it remains extremely hot.e. the sum of Earth’s dipole field and the local rocks’ atomic dipoles.

45. The rate of sea-floor spreadinga. is the same wordwide.b. varies between 1 and 6 ft per year.c. is faster along the Mid-Atlantic Ridge than along the East Pacific Rise.d. has remained constant throughout Earth’s history.e. is fast enough to account for the formation and destruction of oceans many times in Earth’s history.

46. Choose the FALSE statement. Magnetic reversalsa. have occurred many times, but not at regular intervals.b. reflect changes in the direction of flow of molten iron in Earth’s outer core.c. happen slowly as the poles wander and finally cross the equator.d. are recorded in strips of rock parallel to the mid-ocean ridge.e. are a global phenomenon.

47. Earth’s magnetic north polea. coincides with Earth’s geographic North Pole.b. is always within 2 degrees of the geographic North Pole.c. stays constant over geologic time.d. is the place your compass needle points toward.e. All of the above are true.

48. Which of the following statements is NOT true about the ocean floor?a. It is covered by a layer of sediment composed of clay and plankton shells.

b. The heat flow through it is greatest at the mid-ocean ridges.c. Oceanic crust contains granite and metamorphic rocks.d. Ocean crust contains basalt and gabbro.e. Oceanic crust is quite different from continental crust.

49. Basalt isa. cooled iron-rich lava.b. typical continental crust.c. lacking in iron.d. incapable of recording paleomagnetism.e. All of the above are true.

50. “Grains of magnetite become permanent magnets aligned along Earth’s magnetic field as molten rock cools.” This is a description of the way

a. gabbro records polar wandering.b. magnetic reversals occur.c. paleopoles migrate in respect to fixed continents.d. continents wander in respect to fixed pelopoles.e. basalt creates a paleomagnetic record.

51. The relative widths of magnetic anomalies on the sea floor correspond to thea. intervals between magnetic reversals.b. magnetic strengths of the anomalies.c. All of the above.d. None of the above.

52. Which of the following forces impact plate movement?a. Seismic activity caused by oceanic currents.b. Climate changes in the atmosphere.c Convection currents in the Earth’s mantle.d. Rotation of the Earth’s inner core.

53. Hot spots are formed by which of the following?a. Riftingb. Subductionc. Earthquakesd. Mantle plumes

54. Which of the following is an example of a passive margin?a. The western coast of North Americab. The eastern coast of Greenlandc. The western coast of South Americad. The coasts of Japan

55. The Mohorovicic Discontinuity isa. The boundary between the Earth’s crust and mantle.b. The layer between the inner and outer core.c. The layer just below the earth’s outer crust.d. The miles of molten rock just below the oceanic crust.

56. Which of these processes is NOT involved in making lithospheric plates move?a. Ridge pushb. Slab pullc. Convection currentsd. Isostatic rebound

57. On the figure above, which island has a currently active volcano?a. Kauaib. Oahuc. Molokaid. Mauie. Hawaii

58. Which island is the oldest island of the chain?a. Kauaib. Oahuc. Molokaid. Mauie. Hawaii

59. Under which island is the location of the origin of the island chain?a. Kauaib. Oahuc. Molokaid. Mauie. Hawaii

60. The distance between point A on Kauai and point B on Hawaii is 550.5 km. The ages of rocks at these points are shown on the diagram. Given the age of the rocks, what has been the average rate of plate motion during the last 4.7 million years (in cm/year)?

a. 258.73 cm/yearb. 117.1 cm/yearc. 11.7 cm/yeard. 2.587 cm/year

Magnified view

A BC

Use the diagram provided to answer the following questions pertaining to the layers of the Earth.

61. What is the name of the layer marked A?a. Oceanic crustb. Oceanic crust, thinc. Continental crust, normald. Continental crust, thickened

62. What is the name of the layer marked B?a. Oceanic crustb. Oceanic crust, thinc. Continental crust, normald. Continental crust, thickened

63. What is the name of the layer marked C?a. Oceanic crustb. Oceanic crust, thinc. Continental crust, normald. Continental crust, thickened

64. The boundary layer at 70 km is calleda. inner coreb. transition zonec. upper mantled. Moho

65. The region from 70 to 440 km defines thea. upper mantleb. transition zonec. Mohod. lower mantle

66. The region from 440 to 670 km defines thea. outer coreb. inner corec. transition zoned. Moho

67. The region from 670 to 2,900 km defines thea. upper mantleb. lower mantlec. outer cored. inner core

68. The region from 2,900 to 5,150 km defines thea. Mohob. transition zonec. inner cored. outer core

69. The region from 5,150 to 6,370 km defines thea. inner coreb. Mohoc. outer cored. upper mantle

70. Earth’s lithosphere is broken into about ________ platesa. 20b. 22c. 34d. 18e. 41

71. Every year Earth’s magnetic declination changes by about ____________ degrees.a. 0.7-1.0b. 0.2-0.5c. 0.1-1.0d. 1.2-1.5e. 2.0-2.3

72. Earth’s last magnetic reversal occurred about ______________ ago.a. 500,000 yearsb. 250,000 yearsc. 2,000,000 yearsd. 7,000,000 yearse. 700,000 years

73. Two ways the age of rock can be determined area. by carbon dating and age of rocks presentb. by using x-rays to determine depth of layers and number of fossils presentc. by radiometric dating and age of fossils presentd. by careful excavation and number of layers exposede. by its geographic location and ratio of sedimentary to igneous rocks

74. Fossil distribution of land-dwelling creatures of the late Paleozoic/early Mesozoic suggest that which five land masses must have been joined at one time?

a. Africa, South America, India, Antarctica, Australiab. Africa, South America, India, Asia, Australiac. Asia, South America, North America, Antarctica, Australiad. Africa, South America, North America, Antarctica, Greenlande. Africa, Greenland, India, Antarctica, Australia

75. Which of the following is an example of Isostasy?a. The height of land increased after glaciers retreated from North America.b. The height of land decreased after glaciers retreated from North America.c. The height of land remained constant after glaciers retreated from North America.d. The height of land was eroded by glaciers as they retreated from North America.

76. The Orogenic Cycle describes the process of forming which geologic feature?a. Rift valleysb. Trenchesc. Pangaead. Mountains

77. Which of the following is formed mainly due to tension force?

a. Strike-Slip Faultb. Reverse Faultc. Subductive Faultd. Normal Fault

78. Plate tectonic theory was widely accepted by scientists in the 1930s.a. Trueb. False

79. Earth’s magnetism is due to the flow of liquid iron in Earth’s molten outer core.a. Trueb. False

80. Earth’s magnetism changes through slight yearly shifting and occasional reversals of polarity.a. Trueb. False

81. Military needs during World War II resulted in increased study of the sea floor.a. Trueb. False

82. Sea-floor crust is the same age and made up of the same type rock as continental crust.a. Trueb. False

83. The sea floor is covered by a thick, uniform blanket of sediment.a. Trueb. False

84. Locations of past glaciers can be deduced by deposits of till.a. Trueb. False

85. Deposits of coal, reef, sand dunes, and salt were found where Wegener predicted; this supported his ideas.a. Trueb. False

86. The diagram to the right is geologic evidence that a. The salinity of the oceans has been changing over timeb. El Nino has positive and negative yearsc. Subduction is a recycling processd. The earth’s polarity has periodically reversed over time

87. The information in this figure was used to provea. The theory of plate tectonicsb. Uniformatarianismc. Law of superpositiond. Hutton’s concept of plutonism

88. The information in this figure was used to build an understanding ofa. The Leopold convection theoryb. Polar wandering

c. the frequency of ice agesd. isostatic rebound

89. Boundary South American plate and African platea. Transform plate boundaryb. Convergent plate boundaryc. Divergent plate boundary

90. Boundary between North American plate and Pacific plate is a a. Transform plate boundaryb. Convergent plate boundaryc. Divergent plate boundary

91. Boundary between Nazca plate and South American platea. Transform plate boundaryb. Convergent plate boundaryc. Divergent plate boundary

92. Boundary between African plate and Antarctic platea. Transform plate boundaryb. Convergent plate boundaryc. Divergent plate boundary

93. On average, which of these is likely to be the oldest?a. Continental Crustb. Ocean crustc. Mountains resulting from a hotspotd. Seamounts

94. Which of these came first?a. Laurasiab. Gondwanac. North American Cratond. Pangaea

A

G

FE

DC

B

95. All of these are a cause of land bridges opening and closing EXCEPT:a. Ice agesb. Sea level changec. Continental driftd. The ring of fire

The figure to the right are the steps in the Wilson Cycle. 96. Which of these is the correct orderof steps, starting with a Stable Craton:

a. F, A, G, D, E, B, Cb. F, C, A, G, D, E, Bc. F, G, A, E, B, D, Cd. F, D, G, B, A, C, Ee. F, B, C, A, G, E, D

97. Which of the earth’s layers is all liquid?a. Crustb. Mantlec. Outer cored. Inner core

98. When a land bridge opens, it can have all of the following effects except:a. Allows animals to migrateb. Affects isostasyc. Changes circulation in the oceand. Increases genetic diversity in species

99. The lithosphere is made up of what two layers?a. Mantle and ocean crustb. Asthenosphere and upper mantlec. Lower crust and upper crustd. Crust and upper mantle

100. The process by which the rigid outer shell ‘floats’ on the asthenosphere is called?a. Buoyant actionb. Isostasyc. Epigenicd. Orogenic