For each statement or question, select
the word or expression that best
completes the statement or answers the
question.
____ 1. Today, ships use a device called
a precision depth recorder to
A. collect samples of seafloor sediments
B. determine the distance to the sea
floor
C. sample rocks from the sea floor
D. make a videotape of the sea floor
____ 2. Which sea-floor feature is not
commonly found at active continental
margins?
A.
B.
C.
D.
deep-sea trench
continental rise
continental slope
continental shelf
____ 3. Satellites can obtain information
about the sea floor because
A. the satellite can "see" through
seawater
B. sea-floor sediments radiate infrared
light
C. the color of the surface water varies
with sea-floor depth
D. the sea surface level varies slightly
with seafloor depth
____ 4. One method of obtaining a sample
of sea-floor sediment with its layers
preserved involves using a
A.
B.
C.
D.
lead-weighted line
grab sampler
gravity corer
sonar device
____ 5. The shelf edge is the boundary
between the continental shelf and the
A.
B.
C.
D.
shoreline
continental slope
deep-ocean trench
continental rise
____ 6. Passive continental margins are
characterized by the presence of
A.
B.
C.
D.
coastal plains
earthquake activity
oceanic trenches
rugged coastal mountains
____ 7. Suppose sound travels at an
average rate of 1500 meters per second
through seawater above a particular
location. How deep is the ocean if a
sound pulse takes 10 seconds to reach the
bottom <i>and</i> return to a surface
ship?
A. 150 meters
B. 300 meters
C. 7500 meters
D. 15,000 meters
____ 8. The portions of large submarine
canyons that cut through the lower
continental slope are thought to have
been carved out by
A.
B.
C.
D.
earthquakes
changing sea level
rivers
turbidity currents
____ 9. The ultimate source of most of
the material found on the surface of
abyssal plains is
A. sediments carried to the ocean by
continental rivers
B. shells settling from the ocean
surface
C. sediments eroded from abyssal hills
D. sediments produced at mid-ocean
ridges
____ 10. Abyssal hills are commonly found
on the sea floor
A.
B.
sea
C.
D.
on the continental slope
between continental rises and deeptrenches
on the continental shelf
next to oceanic ridge systems
____ 11. Deep-sea trenches occur at
convergent plate boundaries where
A. mid-ocean ridges are being created
B. one tectonic plate is sinking beneath
another
C. one tectonic plate is sliding past
another
D. two tectonic plates are pulling apart
from one another
____ 12. Where an oceanic plate descends
beneath a continental plate, what
features are common along the edge of the
continent?
A.
B.
C.
D.
earthquakes and guyots
volcanoes and fracture zones
earthquakes and volcanoes
guyots and fracture zones
____ 13. Mid-ocean ridges are undersea
mountain ranges where lithospheric plates
are
A. moving apart and new oceanic crust is
being formed
B. moving apart and old oceanic crust is
being destroyed
C. pushing together and old oceanic
crust is being pushed up
D. pushing together to form seamounts
and guyots
____ 14. Segments of mid-ocean ridges are
offset relative to each other by
A.
B.
C.
D.
submarine canyons
deep-sea trenches
rift valleys
fracture zones
____ 15. Sinking volcanic islands and
developing coral reefs are related to the
formation of
A.
B.
C.
D.
manganese nodules
atolls
abyssal hills
deep-sea trenches
____ 16. Sediments covering the ocean
floor are
A. of the same general composition
everywhere
B. all coated with a fine layer of rust
that gives them a reddish color
C. dissolved when they sink past the
calcite compensation depth
D. made up of a wide range of sizes that
settle to the sea floor at different
rates
____ 17. Sediments made from microscopic
shells that settle to the bottom when the
organisms that produced them die are
called
A.
B.
C.
D.
terrigenous sediments
cosmogenous sediments
biogenous sediments
manganese nodules
____ 18. As rivers carry continental
sediments to the ocean, the particles
most likely to be deposited on the deepsea floor are
A. muds and clays that can be carried
great distances by currents
B. metals that are commonly found in
manganese nodules
C. sands that are abundant along
coastlines and beaches
D. gravels that can sink quickly through
the water
____ 19. As icebergs melt, they
A. change the level of the calcite
compensation depth
B. change the amount of calcareous
sediments produced in the water around
them
C. release sediments and pieces of rock
that sink to the ocean floor
D. add hydrogenous sediments to the
ocean
____ 20. Sediments containing 75 percent
of the ocean's siliceous sediment are
found near?
A.
B.
C.
D.
Greenland
Iceland
Australia
Antarctica
____ 21. Manganese modules form
A. as sediments settling through the
water clump together
B. at the surface of the sea floor
C. where sediments are scraped off one
lithospheric plate as it subducts beneath
another
D. in areas where sediments accumulate
rapidly
____ 22. Scientists study the remains of
marine organisms in seafloor sediments to
learn about all of the following except
A. the amount of water trapped in
glaciers in the past
B. the history of water temperature at
the seafloor
C. the climate of Earth in the past
D. the composition of terrigenous
sediments
____ 23. Surface currents in the ocean
are primarily driven by
A.
B.
C.
D.
winds
waves
temperature differences
density differences
____ 24. Surface currents flowing away
from the equator carry
A.
B.
C.
D.
cool water
upwelling water
warm water
downwelling water
____ 25. The winds that are most involved
in forming ocean currents worldwide are
the
A.
B.
C.
D.
West Wind Drift and trade winds
trade winds and westerlies
westerlies and monsoons
trade winds and monsoons
____ 26. In some regions there is a
seasonal reversal in the direction of
surface ocean currents due to a reversal
in
A.
B.
C.
D.
seasonal upwelling patterns
seasons of the year
seasonal wind direction
seasonal temperature patterns
____ 27. Two examples of warm ocean
currents are the
A. Gulf Stream and the Kuroshio Current
B. Kuroshio Current and the Canary
Current
C. Canary Current and the California
Current.
D. California Current and the Gulf
Stream
____ 28. The British Isles and Iceland
have warmer climates than they would
otherwise because
A. warm, moist air blows over the
Labrador Current and warms it
B. thick fogs provide insulation to hold
heat in
C. currents carry icebergs farther south
before they melt
D. the North Atlantic Drift carries warm
water across the Atlantic
____ 29. Which of the following contains
a core of Sargasso Sea water?
A. cold-core rings
of the Gulf Stream
B. cold-core rings
the Gulf Stream
C. warm-core rings
of the Gulf Stream
D. warm-core rings
the Gulf Stream
on the continent side
on the ocean side of
on the continent side
on the ocean side of
____ 30. What type of current flows in
the opposite direction of wind-related
currents?
A.
B.
C.
D.
oppositional currents
density currents
countercurrents
tidal currents
____ 31. Deep ocean currents are driven
by
A.
B.
C.
D.
tidal forces
differences in density
differences in oxygen content
changes in conveyor belt circulation
____ 32. The circulation of ocean water
is an efficient way to transport
A.
B.
C.
D.
heat
oxygen
density
evaporation
____ 33. Changes in density that lead to
the formation of deep ocean density
currents include all of the following
except
A.
B.
C.
D.
evaporation
cooling
freezing
melting
____ 34. Turbidity current density
results from water mixing with
A.
B.
C.
D.
higher salinity water
colder water
cold-core rings
sediment particles
____ 35. When seawater freezes, most of
the salt
A. is included in the ice, increasing
its density
B. is left behind, increasing the
density of the remaining seawater
C. is included in the ice, decreasing its
density
D. is left behind, decreasing the
density of the remaining seawater
____ 36. The cause of the density current
that flows over the Strait of Gibraltar
into the Atlantic Ocean is
A.
B.
C.
D.
cooling
evaporation
freezing
mixing with sediment
____ 37. Upwelling is important to sea
life because it
A.
B.
C.
D.
cools the surface water
brings nutrients to the surface water
keeps ocean temperature uniform
brings carbon dioxide to the surface
____ 38. Upwelling occurs along the
western edges of continents, where
surface water
A.
B.
C.
D.
flows
flows
flows
stops
away from land
toward land
northward along the coastline
flowing
____ 39. Major commercial fishing areas
are usually located in areas
A. where density currents form
B. where seawater oxygen levels are high
C. of persistent upwelling
D. that experience frequent turbidity
currents
____ 40. The gravitational pulls of the
moon and sun cause Earth's tides. The
sun's effect is about
A.
B.
C.
D.
one quarter that of the moon's
half that of the moon's
equal to that of the moon's
double that of the moon's
____ 41. Tides are highest when Earth is
in line with
A.
B.
C.
D.
the moon
the sun
both the sun and moon
the tidal range
____ 42. The difference between high tide
and low tide is most noticeable
A.
B.
C.
D.
on the open ocean
during neap tides
when the moon is at apogee
in long, narrow bays
____ 43. Which of the following is
supplied to deep-sea life by density
currents that form at the surface and
then sink?
A.
B.
C.
D.
oxygen
food
warmth
salinity
____ 44. An area famous for its large
tidal range is
A.
B.
C.
D.
Lake Superior
the Gulf of Mexico
the Great Salt Lake
the Bay of Fundy