Deck 9: Circulation of the Ocean

Question 1

Which water mass is not produced by caballing?

A) North Atlantic Intermediate Water
B) Antarctic Intermediate Water
C) Antarctic Bottom Water
D) Mediterranean Deep Water

Answer 1

D
The Mediterranean Deep water is not produced by caballing. Some Antarctic Bottom Water is produced by caballing or the mixing and sinking of water masses. Information can be found in the section Thermohaline Circulation Affects All the Ocean's Water.

Question 2

What is La Niña?

A) A warmer than normal circulation event
B) A circulation due to density and salinity
C) A colder than normal circulation event
D) The result of volcanic eruptions

Answer 2

C
La Niña events are characterized by strong currents, powerful upwelling, and stormy conditions. These colder than normal events are the response to El Niño events. Information can be found in the section El Niño and La Niña Are Exceptions to Normal Wind and Current Flow.

Question 3

How many water masses are common in tropical and temperate latitudes?

A) Three
B) Four
C) Five
D) Six

Answer 3

C
The water masses present in temperate and tropical waters are named for their relative positions in the water column. These water masses are surface water, central water, intermediate, deep water, and bottom water. Information can be found in the section Thermohaline Circulation Affects All the Ocean's Water.

Question 4

What powers a Slocum glider?

A) Batteries
B) Photovoltaics
C) Currents
D) Gravitational energy, buoyancy, and heat

Question 5

What influences contour currents?

A) Salinity
B) Density
C) Topography
D) Trade winds

Question 6

What is responsible for the large-scale global ocean circulation?

A) Surface currents
B) ENSO events
C) Thermohaline circulation
D) Langmuir circulation

Question 7

If an eddy found in the Gulf Stream is rotating counterclockwise, then it is:

A) a warm water eddy.
B) a cold water eddy.
C) a transverse current.
D) an eastern boundary current.

Question 8

Where is density stratification the least pronounced?

A) Temperate latitudes
B) Polar latitudes
C) Tropical latitudes
D) Areas where there is upwelling

Question 9

What maintains the permanent thermocline found at all low and mid-latitudes?

A) Continual upwelling
B) Warm water currents
C) Density stratification
D) Downwelling

Question 10

What thrusts water masses that are engaged in the thermohaline flow of the world's ocean?

A) Density
B) Gravity
C) Trade winds
D) Coriolis Effect

Question 11

What is a characteristic of Antarctic Bottom Water?

A) Extreme density
B) The water moves south towards Antarctica along the seafloor
C) Fast moving
D) Most is produced near the Mediterranean and joins the deep bottom layer

Question 12

Why are fisheries heavily impacted by ENSO events?

A) Upwelling ceases
B) Nutrient-rich currents are interrupted when the trade winds shift
C) Low pressure systems create downwelling events rather than the normal upwelling
D) Rise in sea level effects migration patterns

Question 13

What is not a characteristic of an El Niño Southern Oscillation (ESNO)?

A) High pressure area shifts to the western Pacific
B) Trade winds across the Pacific weaken or reverse directions
C) Equatorial currents stop
D) Trade winds across the Pacific strengthen

Question 14

What does not affect surface currents?

A) Gravity
B) Coriolis Effect
C) Wind
D) Density

Question 15

What is not a characteristic of western boundary currents?

A) They move warm water poleward.
B) They are fast moving currents.
C) They are deep currents.
D) They are broad currents.

Question 16

What is another name for undercurrents?

A) Equatorial currents
B) Transverse currents
C) Countercurrents
D) Subterranean currents

Question 17

What is considered to be the largest western boundary current?

A) Canary Current
B) Gulf Stream
C) Brazil Current
D) East Australian Current

Question 18

What is the name for slow, deep currents beneath the pycnocline?

A) Surface currents
B) Convection currents
C) Thermohaline currents
D) Polar currents

Question 19

What is used to visualize ocean layering?

A) A caballing chart
B) A circulation histogram
C) A layering table
D) A temperature-salinity diagram

Question 20

What mechanism is being used to gain new information regarding deep sea circulation?

A) Acoustic tomography
B) ACDP systems
C) Electromagnetic field detectors
D) Drift cards

Question 21

The Antarctic Bottom Water in the Pacific retains its characteristics for up to 1,600 years.

Question 22

How long does it take most deep water to rise to the surface?

A) 100 to 200 years
B) 200 to 300 years
C) 500 to 600 years
D) 1,500 to 1,600 years

Question 23

Surface currents move water vertically which thoroughly mixes the uppermost 400 meters of the ocean's surface.

Question 24

Thousands of lost shoes in the Pacific helped oceanographers refine circulation models.

Question 25

What is the disadvantage of using drift bottles to study currents?

A) They must be continuously monitored by radar.
B) They are not successful for determining coastal circulations.
C) The intermediate movements of the bottles are unknown.
D) They are frequently lost.

Question 26

What is not usually able to be measured by flow meters?

A) Surface currents
B) Intermediate waters
C) Bottom waters
D) Coastal waters

Question 27

Although gyres flow continuously, oceanographers categorize them into four interconnected currents.

Question 28

The horizontal movement of water by wind can lead to vertical movement in surface water.

Question 29

The global conveyer belt transports juvenile organisms, mixes nutrients, and distributes gases and solids.

Question 30

Where does the largest amount of upwelling occur?

A) Equatorial upwelling
B) Polar upwelling
C) Coastal upwelling
D) Mid-latitude upwelling

Question 31

What prevents North Atlantic Deep Water from moving on a large scale like the Antarctic Bottom Water?

A) The density of the water
B) The topography of the basin
C) The composition of the sediments
D) The salinity of the water

Question 32

If the gradual rise of deep water at temperate and tropical zones were to stop, the thermocline would rise, making the difference in water layers steeper.

Question 33

Caballing is the mixing of two water masses with the same density but different temperatures and salinity, resulting in a new water mass with lower density.

Question 34

What is the Ekman spiral?

A) The movement of water in the same direction as the wind above
B) The decreasingly slower movement of water as it gets further away from the wind source
C) The sum of all water directions in wind affected layers
D) The friction created on the ocean's surface layer from wind

Question 35

El Niño Southern Oscillation events can cause flooding from both a rise in sea level and high precipitation.

Question 36

Why is the West Wind Drift not considered a gyre?

A) It is too large to be a gyre.
B) It is a closed circuit current.
C) It is driven by westerly winds.
D) It does not flow around the margins of an ocean basin.

Question 37

What water mass is the most saline?

A) North Atlantic Water
B) Mediterranean Deep Water
C) Antarctic Bottom Water
D) North Atlantic Intermediate Water

Question 38

What direction would a gyre in the Southern Hemisphere flow towards?

A) Left
B) Right
C) Towards the equator
D) Poleward

Question 39

Upwelling can increase biological productivity, but it is unable to influence weather conditions.

Question 40

What is a gyre?

A) A type of vertical circulation
B) A circular flow of water around the periphery of an ocean basin
C) A type of thermohaline current
D) A type of current along the western margins of ocean basins

Question 41

The Gulf Stream has decreased in recent years due to an influx of freshwater.

Question 42

Langmuir circulation disturbs deep water currents due to twisting vortices.

Question 43

What is an El Niño/Southern Oscillation (ENSO) event? La Niña? How are they connected to each other?

Question 44

What are the different types of water masses? What is the most distinctive water mass? Give the characteristics and behaviors of that water mass.

Question 45

What is the behavior of the Ekman spiral? What occurs when the friction depth is reached?

Question 46

The Coriolis Effect and gravity maintains the hill of water present in the center of oceanic gyres.

Question 47

When a large amount of dense water sinks at polar ocean basins, the same quantity rises elsewhere in the world ocean.

Question 48

What is the global conveyer belt referring to? How does this thermohaline flow transport heat throughout the world ocean? Include aspects of upwelling and downwelling.

Question 49

Researchers believe the catalyst for the 1982-83 El Niño event was actually the volcanic eruption of El Chichón.

Question 50

What are the three types of geostrophic currents? What are their characteristics? Give at least one example of each type of current.