Essentials of Oceanography 13th Edition Test
Bank and Exam Review 2026/2027 – Complete
Exam-Style Questions with Correct Answers &
Detailed Rationales | Verified & Reliable
1. Which property of seawater most directly causes its density
to increase?
A. Decreased salinity and increased temperature
B. Increased temperature and decreased pressure
C. Increased salinity and decreased temperature
D. Decreased salinity and decreased pressure
Rationale: Seawater becomes denser when salinity increases
because dissolved salts add mass without proportionally
increasing volume. Cooling also generally increases seawater
density because colder water molecules occupy less volume.
Pressure increases density as well, but its effect is relatively
small near the surface compared with temperature and salinity.
2. Why does the ocean have a much greater capacity to store
heat than the atmosphere?
A. Seawater reflects nearly all incoming solar radiation
B. Water has a high specific heat capacity
,C. Seawater has a lower density than air
D. Ocean water does not participate in convection
Rationale: Water requires a large amount of energy to change
its temperature, giving it a high specific heat capacity. The
enormous mass of the oceans therefore allows them to absorb
and store substantial amounts of thermal energy while
undergoing relatively modest temperature changes.
3. Which process is primarily responsible for the formation of
deep water in the North Atlantic?
A. Strong solar heating at the equator
B. Increased precipitation over the subtropical ocean
C. Upwelling caused by trade winds
D. Cooling and increased salinity that make surface water
dense enough to sink
Rationale: In the North Atlantic, surface seawater can become
especially dense through cooling and, in some regions, salinity
increases associated with evaporation and sea-ice formation.
Once sufficiently dense, the water sinks and contributes to
North Atlantic Deep Water formation, an important component
of global thermohaline circulation.
4. What is the primary cause of ocean tides on Earth?
,A. Seasonal changes in ocean temperature
B. Atmospheric pressure differences
C. Gravitational interactions involving the Moon and Sun
D. Coriolis acceleration
Rationale: Tides result principally from the gravitational forces
of the Moon and, to a lesser extent, the Sun acting on Earth's
oceans. The Moon's relatively close proximity makes its tidal
influence stronger than that of the Sun.
5. Which statement best describes the Coriolis effect in the
Northern Hemisphere?
A. Moving objects are deflected to the left
B. Moving objects are deflected to the right relative to their
direction of motion
C. Moving objects experience no deflection at the poles
D. Moving objects always accelerate toward the equator
Rationale: Earth's rotation causes moving air and water to
appear deflected to the right in the Northern Hemisphere and to
the left in the Southern Hemisphere. The effect is strongest
toward the poles and approaches zero at the equator.
6. A parcel of seawater is transported away from the equator
toward higher latitudes. Assuming no significant mixing or
, freshwater input, what generally happens to its density as it
cools?
A. It decreases because colder water contains less energy
B. It remains constant because salinity determines density
exclusively
C. It increases because cooling generally makes seawater
denser
D. It decreases because pressure decreases toward the poles
Rationale: For typical seawater conditions, cooling increases
density. Temperature is one of the three principal controls on
seawater density, along with salinity and pressure. Although
unusual freshwater-like behavior occurs near the freezing point
under certain conditions, ordinary seawater generally becomes
denser as it cools.
7. Which ocean zone receives sufficient sunlight for
photosynthesis to occur?
A. Abyssal zone
B. Hadal zone
C. Bathypelagic zone
D. Euphotic zone
Rationale: The euphotic zone is the sunlit upper portion of the
ocean where enough photosynthetically active radiation
Bank and Exam Review 2026/2027 – Complete
Exam-Style Questions with Correct Answers &
Detailed Rationales | Verified & Reliable
1. Which property of seawater most directly causes its density
to increase?
A. Decreased salinity and increased temperature
B. Increased temperature and decreased pressure
C. Increased salinity and decreased temperature
D. Decreased salinity and decreased pressure
Rationale: Seawater becomes denser when salinity increases
because dissolved salts add mass without proportionally
increasing volume. Cooling also generally increases seawater
density because colder water molecules occupy less volume.
Pressure increases density as well, but its effect is relatively
small near the surface compared with temperature and salinity.
2. Why does the ocean have a much greater capacity to store
heat than the atmosphere?
A. Seawater reflects nearly all incoming solar radiation
B. Water has a high specific heat capacity
,C. Seawater has a lower density than air
D. Ocean water does not participate in convection
Rationale: Water requires a large amount of energy to change
its temperature, giving it a high specific heat capacity. The
enormous mass of the oceans therefore allows them to absorb
and store substantial amounts of thermal energy while
undergoing relatively modest temperature changes.
3. Which process is primarily responsible for the formation of
deep water in the North Atlantic?
A. Strong solar heating at the equator
B. Increased precipitation over the subtropical ocean
C. Upwelling caused by trade winds
D. Cooling and increased salinity that make surface water
dense enough to sink
Rationale: In the North Atlantic, surface seawater can become
especially dense through cooling and, in some regions, salinity
increases associated with evaporation and sea-ice formation.
Once sufficiently dense, the water sinks and contributes to
North Atlantic Deep Water formation, an important component
of global thermohaline circulation.
4. What is the primary cause of ocean tides on Earth?
,A. Seasonal changes in ocean temperature
B. Atmospheric pressure differences
C. Gravitational interactions involving the Moon and Sun
D. Coriolis acceleration
Rationale: Tides result principally from the gravitational forces
of the Moon and, to a lesser extent, the Sun acting on Earth's
oceans. The Moon's relatively close proximity makes its tidal
influence stronger than that of the Sun.
5. Which statement best describes the Coriolis effect in the
Northern Hemisphere?
A. Moving objects are deflected to the left
B. Moving objects are deflected to the right relative to their
direction of motion
C. Moving objects experience no deflection at the poles
D. Moving objects always accelerate toward the equator
Rationale: Earth's rotation causes moving air and water to
appear deflected to the right in the Northern Hemisphere and to
the left in the Southern Hemisphere. The effect is strongest
toward the poles and approaches zero at the equator.
6. A parcel of seawater is transported away from the equator
toward higher latitudes. Assuming no significant mixing or
, freshwater input, what generally happens to its density as it
cools?
A. It decreases because colder water contains less energy
B. It remains constant because salinity determines density
exclusively
C. It increases because cooling generally makes seawater
denser
D. It decreases because pressure decreases toward the poles
Rationale: For typical seawater conditions, cooling increases
density. Temperature is one of the three principal controls on
seawater density, along with salinity and pressure. Although
unusual freshwater-like behavior occurs near the freezing point
under certain conditions, ordinary seawater generally becomes
denser as it cools.
7. Which ocean zone receives sufficient sunlight for
photosynthesis to occur?
A. Abyssal zone
B. Hadal zone
C. Bathypelagic zone
D. Euphotic zone
Rationale: The euphotic zone is the sunlit upper portion of the
ocean where enough photosynthetically active radiation
