OCE1101 Chapter 7

What factor(s) drive(s) Ekman transport? Choose all that apply. A. Coriolis effect B. water temperature C. water salinity D. boat movement E. wind

- Coriolis effect - wind

Of the following methods, which are indirect methods for measuring currents? Choose all that apply.

- Doppler flow meter - Dynamic topography - Pressure gradients

Of the following locations, where would upwelling be expected to occur? Choose all that apply.

- In areas of diverging surface currents - Where seamounts or tablemounts are present - Where there is a sharp bend in a coastline

Of the following conditions, which is/are related to strong El Niño events? Choose all that apply.

- Increase in sea-surface temperatures and destruction of coral reefs in the eastern Pacific Ocean - Higher sea levels in the eastern Pacific Ocean associated with warmer water - Increased abundance of hurricanes in the eastern Pacific Ocean

Of the following gyres, which one(s) flow in a counterclockwise direction? Choose all that apply.

- South Atlantic Subtropical Gyre - Northern Hemisphere Subpolar Gyres - South Pacific Subtropical Gyre - Indian Ocean Subtropical Gyre

Which of the following statements is/are true regarding subtropical convergence? Choose all that apply. A. Subtropical convergence produces a hill of piled up water in the center of each gyre in the southern hemisphere that is deflected towards the east. B. Subtropical convergence produces a hill of piled up water in the center of each gyre in the northern hemisphere that is deflected towards the west. C. Subtropical convergence is caused by the clockwise rotation of each gyre in the southern hemisphere. D. Subtropical convergence causes a bulge of surface water that can be as high as 2 meters. E. Subtropical convergence is caused by the clockwise rotation of each gyre in the northern hemisphere.

- Subtropical convergence produces a hill of piled up water in the center of each gyre in the northern hemisphere that is deflected towards the west. - Subtropical convergence causes a bulge of surface water that can be as high as 2 meters. - Subtropical convergence is caused by the clockwise rotation of each gyre in the northern hemisphere.

On a west coast in the Northern Hemisphere, what happens to surface waters when winds blow from the north? Choose all that apply. A. Surface waters move offshore. B. Surface waters move onshore. C. Upwelling occurs. D. Surface waters move southward, causing a strong coastal current. E. Downwelling occurs.

- Surface waters move offshore. - Upwelling occurs.

On a west coast in the Northern Hemisphere, what happens to surface waters when winds blow from the south? Choose all that apply. A. Surface waters move offshore. B. Upwelling occurs. C. Surface waters move onshore. D. Surface waters move northward, causing a strong coastal current. E. Downwelling occurs.

- Surface waters move onshore. - Downwelling occurs.

Recall that global winds impact the direction of surface ocean currents. Examine the following map showing the Atlantic Ocean off the west coast of Africa. The direction of the surface current and the prevailing wind do not coincide. What can explain this discrepancy? Select the two that apply. A. The current is being pulled in a clockwise direction because the subtropical gyre is located in the Southern Hemisphere. B. The ocean current is being deflected to the right due to the Coriolis effect. C. The Coriolis effect deflects ocean currents in the Southern Hemisphere to the left due to Earth's rotation. D. Because the current is located in the Southern Hemisphere, the subtropical gyre pulls the current in a counterclockwise direction.

- The Coriolis effect deflects ocean currents in the Southern Hemisphere to the left due to Earth's rotation. - Because the current is located in the Southern Hemisphere, the subtropical gyre pulls the current in a counterclockwise direction.

Which of the following are true of western boundary currents? Choose all that apply. A. weak, as compared to eastern boundary currents B. they flow along the more gradual slope of the hill of water C. wide, as compared to eastern boundary currents D. fast, as compared to eastern boundary currents E. deep, as compared to eastern boundary currents

- fast, as compared to eastern boundary currents - deep, as compared to eastern boundary currents

Surface ocean currents ___. CHOOSE ALL THAT APPLY. A. transfer large amounts of heat from the high latitudes toward the equator B. form large rotating gyres in the major ocean basins C. are influenced by Coriolis effect D. are driven by winds

- form large rotating gyres in the major ocean basins - are influenced by Coriolis effect - are driven by winds

Actual geostrophic flow is created by which of the following? Choose all that apply. A. gravity B. differences in surface ocean temperature C. differences in surface ocean salinity D. friction E. Coriolis effect

- gravity - friction - Coriolis effect

Why does the west coast of South Africa have high biological productivity? Choose all that apply. A. low concentrations of phytoplankton B. lots of coastal upwelling C. winds blowing away from shore D. lots of coastal downwelling E. high concentrations of nutrients in the surface water

- lots of coastal upwelling - high concentrations of nutrients in the surface water

Which of the following are true of eastern boundary currents? Choose all that apply. A. fast, as compared to western boundary currents B. they flow along the more gradual slope of the hill of water C. deep, as compared to western boundary currents D. wide, as compared to western boundary currents E. weak, as compared to western boundary currents

- they flow along the more gradual slope of the hill of water - wide, as compared to western boundary currents - weak, as compared to western boundary currents

In which direction does the surface current move in relation to the wind in the Southern Hemisphere? A. 45 degrees to the left B. 90 degrees to the right C. in the same direction D. 90 degrees to the left E. 45 degrees to the right

45 degrees to the left

Using the T-S diagram shown above, if a water mass has a density of 1.0280 g/cm3 and a salinity of 35.3 ppt, what is its temperature? A. 0 degrees Celsius B. 10 degrees Celsius C. 5 degrees Celsius D. -2 degrees Celsius E. 34.7 degrees Celsius

5 degrees Celsius

What percentage of an icebergs mass is below the waterline?

90%

Western intensification causes:

All the above effects are the result of western intensification. Submit

Peru's residents are familiar with ENSO as it brings a warm current that reduces populations of which animal?

Anchovies

In locations where North Atlantic Deep Water, Antarctic Bottom Water, and Antarctic Intermediate Water are all found, how would they be arranged vertically in the water column? A. North Atlantic Deep Water would be on the bottom, Antarctic Intermediate Water would be in the middle, and Antarctic Bottom Water would be on the top. B. North Atlantic Deep Water would be on the bottom, Antarctic Bottom Water would be in the middle, and Antarctic Intermediate Water would be on the top. C. Antarctic Bottom Water would be on the bottom, Antarctic Intermediate Water would be in the middle, and North Atlantic Deep Water would be on the top. D. Antarctic Bottom Water would be on the bottom, North Atlantic Deep Water would be in the middle, and Antarctic Intermediate Water would be on the top. E. The three water masses would mix and the density of the resulting water would be an average of the three.

Antarctic Bottom Water would be on the bottom, North Atlantic Deep Water would be in the middle, and Antarctic Intermediate Water would be on the top.

Which of the following is the only current that completely circumscribes Earth?

Antarctic Circumpolar

Which of the following currents contributes to the South Western United States being arid?

California Current

Which of the following is true for downwelling?

Carries dissolved oxygen to the deep-sea floor

Water with which of the following characteristics would be the densest? A. Cold water with low salinity would be the densest. B. Warm water with low salinity would be the densest. C. Cold water with high salinity would be the densest. D. Warm water with high salinity would be the densest.

Cold water with high salinity would be the densest.

Which conditions in the ocean promote high productivity?

Cold water, rich nutrients

Why do the lengths of the arrows in the Ekman spiral get shorter and shorter as you move deeper into the water column? A. The Coriolis effect weakens as depth increases. B. Deeper water moves at a slower speed due to friction. C. There is less light transmission with increased depth. D. The temperature gets colder with depth. E. There is less water in each progressive layer

Deeper water moves at a slower speed due to friction.

Which method would be most appropriate for directly measuring the flow rate of the Gulf Stream? A. Radioactive tracers B. Radar altimeter C. Argo floats D. Doppler flow meter E. Drift bottles

Drift bottles

The California Current is an example of which of the following types of currents?

Eastern Boundary Current

The area in the enclosed rectangle in the false-color map of sea surface temperatures is an example of which of the following features?

Eddies

The world's two main iceberg-producing regions are ________.

Greenland and Antarctica

Which of the following currents contributes to the South Eastern United States being humid?

Gulf Stream

What is the Walker Circulation Cell? A. It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the North Pacific under normal conditions. B. It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the South Atlantic under normal conditions. C. It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the South Pacific under El Niño conditions. D. It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the South Pacific under normal conditions. E. It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the South Atlantic under El Niño conditions.

It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the South Pacific under normal conditions.

Which swift-flowing surface current in a major subtropical gyre transports a large volume of warm water from the equator toward the mid-latitudes?

Kuroshio Current

Which of the following water masses has the highest average salinity? A. North Atlantic Deep Water B. Antarctic Bottom Water C. Antarctic Intermediate Water D. Mediterranean Intermediate Water

Mediterranean Intermediate Water

Palm trees associated with the subtropics can be found at the northern tip of the British Isles in Scotland. This is due to the transfer of heat from the

North Atlantic Current

The North Atlantic Current is an example of which of the following types of currents?

Northern Boundary Current

Which of the following is a direct method for measuring surface currents?

Propeller flow meter

Which of the following methods are used to measure ocean surface currents directly?

Radio-transmitting float bottles

The West Wind Drift is an example of which of the following types of currents?

Southern Boundary Current

The deepest and densest water mass in the world ocean is formed in the __________________.

Southern Ocean Submit

The observation of a hill of water within all subtropical gyres is an example of which of the following?The observation of a hill of water within all subtropical gyres is an example of which of the following?

Subtropical convergenceSubtropical convergence

What would you expect weather to be like on the eastern coast of Australia if the western coast of South America were experiencing unusually warm, wet weather? A. The eastern coast of Australia would be experiencing unusually wet weather. B. The eastern coast of Australia would be experiencing unusually warm weather. C. The eastern coast of Australia would be experiencing unusually cool weather. D. The eastern coast of Australia would be experiencing unusually dry weather.

The eastern coast of Australia would be experiencing unusually dry weather.

In a severe warm phase of the El Niño-Southern Oscillation (ENSO), fisheries' productivity on the west coasts of the Americas is dramatically reduced. Which stage of ENSO would come just before the fisheries' collapse?

The thermocline deepens in eastern boundary currents of the Pacific Ocean subtropical gyres.

_________ is caused by density changes near the poles and equator.

Thermohaline circulation

Which of the following is true of surface water circulation near Antarctica?

Two circumpolar currents dominate it, one current that moves water to the east and one current that moves water to the west.

What depth does Argo floats collect data?

Upper 2,000 meters

The Agulhas Current is an example of which of the following types of currents?

Western Boundary Current

In the figure above, if this is a western-facing coast of the Northern Hemisphere, which wind pattern would cause coastal downwelling? A. Wind A B. Wind B C. Wind C D. Wind D E. All wind patterns would cause coastal downwelling.

Wind C

In the figure above, if this is a western-facing coast of the Southern Hemisphere, which wind pattern would cause coastal upwelling? A. Wind A B. Wind B C. Wind C D. Wind D E. All four wind patterns would cause coastal upwelling.

Wind C

Why does upwelling occur along the west coast of South America under normal conditions? A. Winds moving northward in the South Pacific drive ocean currents toward the north; deep water rises to replace water driven northward. B. Winds moving southward in the South Pacific drive ocean currents toward the south; deep water rises to replace water driven southward. C. Winds moving westward in the South Pacific drive ocean currents toward the west; deep water rises to replace water driven westward. D. Winds moving eastward in the South Pacific drive ocean currents toward the east; deep water rises to replace water driven eastward.

Winds moving westward in the South Pacific drive ocean currents toward the west; deep water rises to replace water driven westward.

The thermocline is _________________. A. a steep gradient in the ocean that separates deeper less salty water from saltier upper water. B. a steep temperature gradient in the ocean that separates deeper cold water from warmer upper water C. a steep gradient in the ocean that separates deeper saltier water from less salty upper water D. a steep temperature gradient in the ocean that separates deeper warm water from colder upper water

a steep temperature gradient in the ocean that separates deeper cold water from warmer upper water

Warm ocean currents ___. A. generally flow along the west coasts of continents B. are warmer than 15 degrees Celsius C. are warmer than the surrounding water D. generally flow from high latitudes towards the equator

are warmer than the surrounding water

Waters along the California coast are colder than those along the mid-Atlantic shore of the U.S. because _____________ occurs as surface waters move away from the coast.

coastal upwelling

Downwelling can result from __________.

converging surface currents

Deep ocean currents are driven primarily by ________ . A. Earth's rotation B. latitude C. wind D. density differences E. bathymetry

density differences

Equatorial currents that are part of the subtropical gyres flow ___. Equatorial counter currents between the gyres flow ___ . A. west to east; west to east B. west to east; east to west C. east to west; west to east D. east to west; east to west

east to west; west to east

Which direction do ocean currents in the South Pacific move under El Niño conditions? A. northward B. westward C. eastward D. southward

eastward

During winter months, monsoon winds over the Indian Ocean ________.

flow from land to sea and are dry

Cool ocean currents ___. A. generally flow from high latitudes towards the equator B. are cooler than 15 degrees C C. are still warmer than the surrounding water D. generally flow along the east coasts of continents

generally flow from high latitudes towards the equator

Which type of current flow moves in a circular path around a subtropical convergence, reflecting Ekman transport, gravity, and the Coriolis effect?

geostrophic circulation

Freezing seawater at ______________ leads to increases in salinity and density.

high latitudes

Deep-water currents move ________ volumes of water and are much ________ than surface currents.

larger; slower

What is the overall effect of the stronger than normal trade winds typical of La Niña conditions? A. flipping of the South Pacific ocean current direction from normal conditions B. raising of the South Pacific ocean temperature from normal conditions C. lowering of the South Pacific ocean temperature from normal conditions D. swapping of the South Pacific high and low pressure zones from normal conditions

lowering of the South Pacific ocean temperature from normal conditions

Ocean surface currents transfer about ________ of the total amount of heat from the tropics to the poles.

one-third

The subtropical gyres ___. A. result from changes in water density (due to temperature and salt content) B. drive the trade winds C. are only important because the currents affect ships crossing them D. play a large role in climate

play a large role in climate

Deep ocean currents ___. A. are primarily driven by wind patterns B. include deep water that rises in the North Atlantic and surface water that sinks in the Pacific and Indian Oceans C. result from changes in water density (due to temperature and salt content)

result from changes in water density (due to temperature and salt content)

Records indicate that the ocean is warming faster in the Arctic polar regions than elsewhere. If that continues, a possible consequence could be __________.

slowing of deep-ocean circulation, resulting in lower oxygen levels in deep water

The thickness of sea ice is limited primarily by __________.

the insulating nature of the ice itself

The El Niño Southern Oscillation can best be described as:

the relationship between sea surface temperature and changing atmospheric pressure.

What causes western intensification? A. the clockwise rotation of earth B. the rotation of Earth from east to west C. the rotation of Earth from west to east D. Ekman transport E. Upwelling

the rotation of Earth from west to east

What is the Southern Oscillation? A. the swapping of high and low temperature zones in the South Pacific under El Niño conditions B. the swapping of high and low pressure zones in the South Pacific under normal conditions C. the swapping of high and low temperature zones in the South Pacific under normal conditions D. the swapping of high and low pressure zones in the South Pacific under El Niño conditions

the swapping of high and low pressure zones in the South Pacific under El Niño conditions

The Ekman spiral is caused by:

the wind and the Coriolis effect.

In the figure above, depicting a hypothetical wind direction in an ideal world. The iceberg broke off from the Greenland Ice Sheet and floated into the ocean. Under the prevailing wind conditions, in which direction would the iceberg be pushed? A. toward A B. toward B C. toward C D. toward D E. toward E

toward D

Refer the figure above. In which direction would the entire surface current underneath the Greenland iceberg be expected to travel? A. toward A B. toward B C. toward C D. toward D E. toward E

toward E Submit

Equatorial currents are driven by the:

trade winds.

Under which conditions are droughts and wildfires common in Australia? A. under normal conditions b. under El Niño conditions c. under Walker Circulation conditions d. under La Niña conditions

under El Niño conditions

Surface waters are pushed away from land and replaced by nutrient-rich bottom water through:

upwelling.

Diverging surface waters are areas of ________ and ________ productivity.

upwelling; high

Surface ocean currents are driven primarily by ________ and modified by ________.

wind; the Coriolis effect and land