Oceanography Questions
Duxbury Chapter 4

  1. What portion of the earth is covered by oceanic crust?
    42%
    53%
    65%
    71%
    83%

  2. Which ocean basin is the largest?
    Arctic
    Atlantic
    Indian
    Pacific

  3. Which ocean province is underlain by continental crust?
    Abyssal hills
    Abyssal plains
    Continental rise
    Continental shelf
    Continental slope

  4. In which ocean province would basalt most likely be found exposed on the seafloor?
    Abyssal hills
    Abyssal plains
    Continental rise
    Continental shelf
    Continental slope

  5. Which ocean province is steep and cut by erosional submarine canyons?
    Abyssal hills
    Abyssal plains
    Continental rise
    Continental shelf
    Continental slope

  6. Which ocean province is covered by deep-sea fans?
    Abyssal hills
    Abyssal plains
    Continental rise
    Continental shelf
    Continental slope

  7. In which ocean province are fracture zones most apparent?
    Abyssal hills
    Abyssal plains
    Continental rise
    Continental shelf
    Continental slope

  8. Over which ocean province does the western boundary undercurrent flow?
    Abyssal hills
    Abyssal plains
    Continental rise
    Continental shelf
    Continental slope

  9. What is the nature of the benthic nepheloid layer?
    Altered basalt of the seafloor bedrock
    Fine deposited sediments on the sea floor
    Fine suspended sediments above the sea floor
    Thick deposits of pure quartz sand from beach deposits
    Turbidite deposits in deep sea fans

  10. What type of deep sea sediments have graded bedding?
    Clays.
    Gypsum.
    Limestone.
    Sandstone.
    Turbidites.

  11. What is the age order of sea floor types (the crust underlying them) from oldest to youngest?
    Abyssal hills, abyssal plains, mid-ocean ridge, continental shelf.
    Abyssal plains, abyssal hills, mid-ocean ridge, continental shelf.
    Continental shelf, abyssal plains, abyssal hills, mid-ocean ridge.
    Mid-ocean ridge, abyssal hills, abyssal plains, continental shelf.
    Mid-ocean ridge, abyssal plains, abyssal hills, continental shelf.

  12. Why are the abyssal plains so flat?
    Long-term erosion
    The underlying hills and valleys have been covered with sediments.
    They are a remnant of the earth's original crust.
    Volcanic eruptions at the mid-oceanic ridges form a very smooth ocean floor.
    Volcanic peaks on the seafloor collapse after about 100 million years.

  13. Where are the deepest places in the ocean?
    Abyssal hills.
    Abyssal plains.
    Continental rise.
    Continental slope.
    Trenches.

  14. Where are extensive hydrothermal vents and deep-sea vent communities found?
    Continental shelves.
    Mid-ocean ridges.
    Seamounts.
    Transform faults.
    Trenches.

  15. Which type of hydrothermal vents have the hottest water?
    All about the same
    Black smokers
    Warm-water vents
    White smokers

  16. What sequence of rocks make up ophiolite sequences of the ocean floor from top to bottom?
    Granite, andesite, basalt.
    Granite, diorite, gabbro.
    Pillow basalts, gabbro, sheeted dikes.
    Pillow basalts, sheeted dikes, gabbro.
    Sheeted dikes, pillow basalts, gabbro.

  17. What are flat-topped undersea mountains called?
    Atolls.
    Guyots.
    Rifts.
    Seamounts.
    Trenches.

  18. How tall does a volcanic peak have to rise above the ocean floor to be called a seamount?
    1 km
    2 km
    3 km
    4 km
    It must reach sea level.

  19. What is the clearest example of hot spot volcanism?
    Aleutian Islands
    Cook Islands
    Hawaiian Islands
    Line Islands
    Mariana Islands

  20. Where is the Superswell located?
    Indian Ocean
    North Atlantic Ocean
    North Pacific Ocean
    South Atlantic Ocean
    South Pacific Ocean

  21. Where are coral reefs found?
    In polar waters.
    In tropical waters.
    Only in deep-sea trenches.
    Only around andesitic islands.
    Only around basaltic islands.

  22. Which sequence is thought to represent the evolution of coral reefs around volcanic islands?
    First barrier reefs, then fringing reefs, then atolls.
    First barrier reefs, then atolls, then fringing reefs.
    First fringing reefs, then barrier reefs, then atolls.
    First atolls, then fringing reefs, then barrier reefs.
    First atolls, then barrier reefs, then fringing reefs.

  23. Which seafloor sediment precipitates directly from seawater?
    Biogenous sediment
    Exogenous sediment
    Hydrogenous sediment
    Lithogenous sediment
    All of the above

  24. Which seafloor sediment is derived from land?
    Biogenous sediment
    Exogenous sediment
    Hydrogenous sediment
    Lithogenous sediment
    All of the above

  25. What are manganese nodules an example of?
    Biogenous sediment
    Exogenous sediment
    Hydrogenous sediment
    Lithogenous sediment
    All of the above

  26. Where are manganese nodules found?
    Continental shelves
    Deep ocean floor
    Deep-sea fans
    Top of mid oceanic ridges
    Top of tablemounts

  27. Match each term with its definition.
    Term Definition
    Deposition
    Erosion
    Lithification
    Wethering
    The chemical alteration and breakdown of rock
    The conversion of sediment to rock
    The dropping of sediment into a long-term reservoir
    The picking up and carrying away of sediment

  28. Match each particle type with its grain size.
    Particle Grain size
    Clay
    Cobble
    Pebble
    Sand
    Silt
    1/16-2 mm
    1/256-1/16 mm
    1/4096-1/256 mm
    4-64 mm
    64-256 mm

  29. Which type of sediment is very easy to transport but very difficult to erode?
    Clay
    Cobbles
    Pebbles
    Sand
    Silt

  30. Which common mineral is most resistant to weathering?
    Amphibole
    Feldspar
    Mica
    Olivine
    Quartz

  31. Which feature is not characteristic of a mature sediment?
    Few high temperature minerals
    High clay content
    High degree of sorting
    Rounded grains
    Quartz

  32. Where does most erosion take place?
    Around continental margins
    Around oceanic islands
    In deep-sea trenches
    In the middle of ocean basins
    On land

  33. Where does most deposition take place?
    Around continental margins
    Around oceanic islands
    In deep-sea trenches
    In the middle of ocean basins
    On land

  34. Which marine province is unusual in experiencing significant underwater erosion?
    Abyssal hills
    Abyssal plains
    Continental rise
    Continental shelf
    Continental slope

  35. Which family of minerals are most lithogenous sediments primarily composed of?
    Carbonates
    Halides
    Nitrates
    Silicates
    Sulfates

  36. What is the largest reservoir of carbon on earth?
    Atmosphere
    Carbonate rocks
    Lake water
    Ocean water
    Organic matter

  37. Match each type of organism with the mineral it forms as its skeleton.
    Organism Skeletal material
    Clams
    Coccolithophores
    Corals
    Diatoms
    Foraminifers
    Radiolarians
    Calcium carbonate (CaCO3)
    Silica (SiO2)

  38. At what latitude are most radiolarian oozes found?
    0-10°
    10-30°
    30-50°
    50-70°
    70-90°

  39. At what latitude are most diatom oozes found?
    0-10
    10-30
    30-50
    50-70
    70-90

  40. Which condition promotes the precipitation of calcium carbonate?
    Animal respiration
    Cold water
    High pressure
    Low pH
    Warm water

  41. What is the Calcite Compensation Depth (CCD)?
    The depth at which calcium carbonate and abyssal clays are in equal concentrations
    The depth at which calcium carbonate and silica are in equal concentrations
    The depth at which calcium carbonate concentration is the highest
    The depth at which calcium carbonate dissolves at the same rate it arrives from above
    The depth below which calcium carbonate is never found

  42. How far below sea level is the Calcite Compensation Depth (CCD) on average?
    1000 m
    2000 m
    3000 m
    4000 m
    7000 m

  43. Why are more calcarious oozes found in the South Pacific than in the North Pacific?
    Foraminifera are more dense in the southern hemisphere
    Ocean currents carry most calcite skeletons into the southern hemisphere
    The South Pacific has an unusually high calcium ion conecntration
    The South Pacific has shallower water
    The South Pacific is much warmer than the North Pacific.

  44. What is the typical rate of abyssal clay accumulation on the deep sea floor?
    1 m/year
    1 mm/1000 years
    10 m/year
    10 mm/1000 years
    100 mm/1000 years

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