Question 1

A water mass at depth in the ocean has temperatures and salinities that are usually determined by the conditions present when the water mass was last at the sea surface.

Accepted Answer

This is correct as temperature and salinity of water masses at depth in the ocean are usually determined by the conditions present when the water mass was last at the sea surface due to mixing and circulation patterns in the ocean.

Question 2

The pycnocline of the oceans is usually found at depths exceeding 2000 m.

Accepted Answer

The pycnocline is usually found at depths between 100-1000 m depending on location and conditions, not exceeding 2000 m.

Question 3

The density of Arctic Ocean water is controlled more by salinity than by temperature.

Accepted Answer

This is true. The Arctic Ocean is cold, with temperatures usually around -1.8°C, but its salinity is the main factor that determines its density. The surface waters of the Arctic Ocean are less salty than the waters at lower depths due to ice melting and river runoff, creating a stable layer that can prevent mixing with deeper waters.

Question 4

Wind-driven surface water moves in a complex manner as a function of depth. This is called the ________.

Accepted Answer

The answer of Wind-driven surface water moves in a complex...

Question 5

Isothermal water is stable and does not overturn.

Accepted Answer

Isothermal water is water that has a uniform temperature. This uniformity creates a stable environment that does not experience overturning. Therefore, the statement is true.

Question 6

The pycnocline is an area where temperature changes rapidly with depth.

Accepted Answer

The answer of The pycnocline is an area where temperature...

Question 7

Many combinations of salinity and temperature of seawater can produce the same density of seawater.

Accepted Answer

This is due to the complex relationship between salinity, temperature, and density in seawater. Different combinations of salinity and temperature can produce the same density, which is known as isopycnal mixing. This is important in ocean circulation and the movement of heat and nutrients in the ocean.

Question 8

Temperature affects density in the Arctic Ocean more than salinity.

Accepted Answer

In the Arctic Ocean, salinity has a greater impact on water density than temperature because the temperature range is relatively narrow and close to the freezing point, whereas variations in salinity, due to the melting of sea ice or freshwater inputs, can significantly alter density.

Question 9

Meanders in the Gulf Stream current can pinch off to form warm and cold core ________.

Accepted Answer

The answer of Meanders in the Gulf Stream current can...

Question 10

The properties of seawater at depth are determined by surface conditions in the area where the water sinks.

Accepted Answer

Seawater at depth is formed when surface water in certain areas becomes dense enough to sink due to cooling and/or evaporation. The properties of the seawater at depth are determined by the conditions of the surface water in the area where it sank. For example, if the surface water was warmer and saltier, the water at depth will also be warmer and saltier.

Question 11

Usually temperature, salinity, and pressure distributions cause ocean water density to increase with depth.

Accepted Answer

Temperature, salinity, and pressure are all factors that affect the density of ocean water. As depth increases, pressure increases and temperature decreases, causing water to become more dense. Additionally, areas of high salinity can also contribute to increased density. Therefore, ocean water density usually increases with depth.

Question 12

The density of Mediterranean Intermediate Water is influenced more by salinity than temperature.

Accepted Answer

Mediterranean Intermediate Water is formed by the mixing of Atlantic water with the salty and dense water in the Mediterranean. Therefore, it is primarily influenced by salinity rather than temperature.

Question 13

In an area where surface currents converge, the water upwells.

Accepted Answer

In areas where surface currents converge, the water typically sinks or downwells, not upwells. Upwelling usually occurs in areas where surface currents diverge, allowing deeper, colder, and nutrient-rich water to rise to the surface.

Question 14

Antarctic bottom water has a very narrow range of both salinity and temperature; this water is nearly homogeneous.

Accepted Answer

Antarctic bottom water is formed through a combination of cooling, increased salinity, and increased pressure, which leads to the water becoming very dense and sinking to the bottom of the ocean. This dense water has a very narrow range of salinity and temperature, making it nearly homogeneous.

Question 15

In the oceans, the zone where density of water changes rapidly with depth is called a pycnocline.

Accepted Answer

This is a correct statement.

Question 16

Increasing temperature also increases density.

Accepted Answer

Increasing temperature decreases the density of a substance.

Question 17

Wind blowing across the sea surface can create paired right- and left-handed circulation cells knows as ________ cells, leading to parallel zones of surface convergence and divergence.

Accepted Answer

The answer of Wind blowing across the sea surface can...

Question 18

Water of a lower density usually lies below water of a greater density.

Accepted Answer

Water of a greater density usually sinks below water of a lower density due to gravity. This is why ice floats on water, as it is less dense than liquid water.

Question 19

Increasing salinity increases density.

Accepted Answer

This is because when salt is added to water, it increases the mass of the solution without significantly increasing the volume. As a result, a given volume of saltwater is denser than an equal volume of freshwater.

Question 20

The large ocean surface-current gyres centered on about 30°N ________.
A) rotate counterclockwise
B) do not rotate
C) have depressed surface elevations
D) rotate clockwise
E) alternate their direction of rotation with the seasons

Accepted Answer

The large ocean surface-current gyres centered on about 30°N rotate clockwise.

Quiz 7: Ocean Structure and Circulation