GEOG 1113L Lab 9: Oceans and Coasts Exam Questions and Answers
100% PASS-GSU
1. What is the average salinity of the world’s oceans?
A. 15 parts per thousand
B. 35 parts per thousand
C. 55 parts per thousand
D. 10 parts per thousand
Answer: B
Rationale: The average salinity of ocean water is approximately 35 parts per thousand
(ppt), meaning there are 35 grams of dissolved salts in 1,000 grams of seawater.
2. Which factor most significantly increases the density of seawater?
A. Increased temperature and decreased salinity
B. Decreased temperature and decreased salinity
C. Increased temperature and increased salinity
D. Decreased temperature and increased salinity
Answer: D
Rationale: Cold water is denser than warm water, and salty water is denser than fresh
water; therefore, the densest water is both cold and highly saline.
3. The zone in the ocean where temperature decreases rapidly with depth is
called the:
A. Halocline
B. Pycnocline
C. Thermocline
D. Epipelagic zone
Answer: C
,Rationale: The thermocline is the layer in the ocean where the temperature gradient is
steepest, separating the warm surface layer from the cold deep water.
4. Surface ocean currents are primarily driven by:
A. Density differences
B. The Moon’s gravity
C. Underwater earthquakes
D. Global wind patterns
Answer: D
Rationale: Surface currents are generated by the friction between the atmosphere and the
ocean surface, primarily driven by the prevailing wind systems like the trade winds.
5. In the Northern Hemisphere, the Coriolis effect causes surface currents to
deflect:
A. To the right
B. To the left
C. Straight ahead
D. Downward
Answer: A
Rationale: Due to the Earth’s rotation, the Coriolis effect deflects moving objects and fluids
to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
6. A large system of rotating ocean currents is known as a:
A. Gyre
B. Tide
C. Upwelling
D. Fetch
Answer: A
Rationale: Ocean gyres are large-scale circular current systems found in each of the major
ocean basins, driven by global winds and the Coriolis effect.
, 7. Thermohaline circulation is also known as:
A. The Global Conveyor Belt
B. The Gulf Stream
C. El Niño
D. Tidal flux
Answer: A
Rationale: Thermohaline circulation refers to deep-ocean currents driven by density
differences (temperature and salinity), often called the Global Conveyor Belt.
8. Where does the densest water in the ocean typically form?
A. Equatorial regions
B. Tropical lagoons
C. High latitudes (Polar regions)
D. Mid-latitude estuaries
Answer: C
Rationale: In polar regions, water becomes extremely cold and sea ice formation increases
salinity, making the water dense enough to sink to the ocean floor.
9. The distance over which wind blows across open water is called the:
A. Fetch
B. Amplitude
C. Wavelength
D. Wave train
Answer: A
Rationale: Fetch is the distance over open water that the wind has blown without
obstruction, which determines the size of the waves generated.
100% PASS-GSU
1. What is the average salinity of the world’s oceans?
A. 15 parts per thousand
B. 35 parts per thousand
C. 55 parts per thousand
D. 10 parts per thousand
Answer: B
Rationale: The average salinity of ocean water is approximately 35 parts per thousand
(ppt), meaning there are 35 grams of dissolved salts in 1,000 grams of seawater.
2. Which factor most significantly increases the density of seawater?
A. Increased temperature and decreased salinity
B. Decreased temperature and decreased salinity
C. Increased temperature and increased salinity
D. Decreased temperature and increased salinity
Answer: D
Rationale: Cold water is denser than warm water, and salty water is denser than fresh
water; therefore, the densest water is both cold and highly saline.
3. The zone in the ocean where temperature decreases rapidly with depth is
called the:
A. Halocline
B. Pycnocline
C. Thermocline
D. Epipelagic zone
Answer: C
,Rationale: The thermocline is the layer in the ocean where the temperature gradient is
steepest, separating the warm surface layer from the cold deep water.
4. Surface ocean currents are primarily driven by:
A. Density differences
B. The Moon’s gravity
C. Underwater earthquakes
D. Global wind patterns
Answer: D
Rationale: Surface currents are generated by the friction between the atmosphere and the
ocean surface, primarily driven by the prevailing wind systems like the trade winds.
5. In the Northern Hemisphere, the Coriolis effect causes surface currents to
deflect:
A. To the right
B. To the left
C. Straight ahead
D. Downward
Answer: A
Rationale: Due to the Earth’s rotation, the Coriolis effect deflects moving objects and fluids
to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
6. A large system of rotating ocean currents is known as a:
A. Gyre
B. Tide
C. Upwelling
D. Fetch
Answer: A
Rationale: Ocean gyres are large-scale circular current systems found in each of the major
ocean basins, driven by global winds and the Coriolis effect.
, 7. Thermohaline circulation is also known as:
A. The Global Conveyor Belt
B. The Gulf Stream
C. El Niño
D. Tidal flux
Answer: A
Rationale: Thermohaline circulation refers to deep-ocean currents driven by density
differences (temperature and salinity), often called the Global Conveyor Belt.
8. Where does the densest water in the ocean typically form?
A. Equatorial regions
B. Tropical lagoons
C. High latitudes (Polar regions)
D. Mid-latitude estuaries
Answer: C
Rationale: In polar regions, water becomes extremely cold and sea ice formation increases
salinity, making the water dense enough to sink to the ocean floor.
9. The distance over which wind blows across open water is called the:
A. Fetch
B. Amplitude
C. Wavelength
D. Wave train
Answer: A
Rationale: Fetch is the distance over open water that the wind has blown without
obstruction, which determines the size of the waves generated.
