Chapter Review Answers
1. Sample answer: Surface currents are streamlike movements of water that occur on or near the surface
of the ocean. Deep currents are streamlike movements of ocean water far below the surface.
2. Sample answer: El NiF1o is a change in the water temperature of the Pacific Ocean that produces a
warm current. La NiF1a is a change in the eastern Pacific Ocean in which the surface water
temperature becomes unusually cool.
3. Sample answer: A spring tide is a tide of increased range that occurs during the full and new moons. A
neap tide is a tide of minimum tidal range that occurs during the first and third quarters of the moon.
4. Sample answer: A tide is the periodic rise and fall of the water level in oceans and other large bodies of
water. Tidal range is the difference in levels of ocean water at high tide and low tide.
5. D
6. D
7. C
8. A
9. C
10. A
11. When El Nino occurs, warm surface water remains along the Pacific coast of South America.
Therefore, upwelling does not occur along the coast.
12. A crest is the highest point of a wave, and a trough is the lowest point of a wave. The wavelength of a
wave is the distance between two adjacent wave crests or wave troughs. The wave height is the vertical
distance between the crest and the trough of a wave.
13. During a neap tide, the sun, the moon, and Earth form a right angle, with Earth in the middle. During a
spring tide, the sun, moon, and Earth align in a straight line.
14. The breaker zone is the zone where waves first begin to tumble downward. The surf is the zone
between the breaker zone and the shore. In the surf, water moves toward the shore.
15. The Gulf Stream, which is a warm-water current, creates a relatively mild climate for the British Isles.
16. Deep currents form where the density of ocean water increases. Water density depends on temperature
and salinity.
18. Because the oceans are liquid, they flow more easily than land.
19. It is important to study El NiF1o and La NiF1a because both affect climate, land, and organisms.
20. 12:50 p.m. (The answer 1:15 a.m. is also acceptable.)
21. Global winds blow across Earth’s surface, which creates surface currents in the ocean. The Coriolis
effect is the apparent curving of moving objects from a straight path due to Earth’s rotation. Therefore,
the rotation of Earth causes ocean currents to curve as they move across Earth’s surface. Continental
deflections occur when a surface current comes into contact with a continent. As a result, the surface
currents deflect, or change direction.
22. Answers may vary. Any two currents marked by black arrows are acceptable as warm-water currents.
Any two currents marked by white arrows are acceptable as cold-water currents.
23. Sample answer: Labrador Current would most likely bring a cool climate to Canada and Greenland.
Chapter Review Answers
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continental shelf
Desalination
Salinity
abyssal plain
benthic environment
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nonpoint-source pollution
B
C
D
C
C
A
A
Coastal water in hotter, drier climates typically has higher salinity because less fresh water runs into
the ocean in drier areas and because heat increases the evaporation rate.
Answers may vary. Sample answer: Technology used to study the ocean floor include sonar and
piloted vessels. Sonar stands for “sound navigation and ranging” and is used to determine the ocean’s
depth by sending sound pulses from a ship down into the ocean. Piloted vessels such as Alvin and
Deep Flight are research vessels used to explore the ocean floor.
Sample answer: The two major regions of the ocean floor include the continental margin and the deepocean basin. The continental shelf, the continental slope, and the continental rise are sections of the
continental margin based on depth and changes in slope.
Sample answer: Plankton are microscopic organisms that float freely in freshwater and marine
environments. Examples of plankton are phytoplankton and zooplankton. Nekton are organisms that
swim actively in open water and include sea lions and whales. Benthos are the organisms that live at
the bottom of the ocean, such as crabs and starfish.
Sample answer: Two living resources that are harvested from the ocean include fish and seaweed. Two
nonliving resources that are harvested from the ocean include oil and sea-floor minerals.
Answers may vary. Sample answer: Desalination may also provide a source of minerals, such as salt.
Answers may vary. Sample answer: A bathymetric profile shows what the contour of the ocean floor
looks like. A seismic reading can show the contour of the ocean floor and what rocks beneath the
ocean floor look like.
Sample answer: Nonpoint-source pollution is pollution that comes from many sources rather than from
a single, specific site. An example of nonpoint-source pollution is oil or gasoline that has leaked from
cars onto streets. An example of point-source pollution is trash dumping from barges. Controlling
ocean pollution is difficult, but many countries have taken legal action to protect oceans. For example,
the United States passed the U.S. Marine Protection, Research, and Sanctuaries Act, which prohibits
harmful dumping in the ocean. Beach cleanups run by citizens, such as the Adopt-a-Beach program,
have been very successful in cleaning up polluted beaches.
B
D
bathyal zone; continental slope from 200 m to 4,000 m below sea level
Sample answer: clams