Oceanography Exam 2: Chapter 7

One of the world's most powerful currents, located off the east coast of the United States, is the __________.

Gulf Stream

The current in the northwestern part of the North Atlantic Subtropical Gyre that transports warm water toward the North Atlantic is called the __________.

Gulf Stream

Benguela Current

cold current, southern hemisphere, temperate latitudes

When a meander from the Gulf Stream pinches off into the warm water south of the current, the eddy is called a __________.

cold-core eddy or ring

Ocean frontal systems that spin off from currents such as the Gulf Stream, akin to atmospheric storms, are known as __________.

eddies

Surface or wind-driven currents move water primarily in a vertical direction in the ocean

false

The West Wind Drift occurs at 60°N around the Arctic Circle

false

downwelling

movement of water from the top to the bottom of the water column

deep ocean currents:

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

Thermohaline circulation in the ocean is driven primarily by differences in __________ and __________ among water masses.

temperature; salinity

All are true of the Antarctic Circumpolar Current except:

the Antarctic Circumpolar Current contributes to the development of Antarctic bottom water in the Weddell Sea.

What is the Southern Oscillation?

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

Under which conditions are droughts and wildfires common in Australia?

under El Niño conditions

geostrophic current

water flow driven by gravity and modified by the Coriolis force

Strong upwelling occurs in all of the following except:

where deep ocean water currents are formed

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

wind; the Coriolis effect and land

What is the Walker Circulation Cell?

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

Of the following surface currents, which one(s) flow generally from west to east?

North Pacific Current Equatorial Counter Current West Wind Drift

What have oceanographers determined from analyzing sea floor cores?

climate change and past extinctions

the 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 this coast

coastal upwelling

Of the following conditions, which is/are related to strong El Niño events?

1) Increased abundance of hurricanes in the eastern Pacific Ocean 2) Higher sea levels in the eastern Pacific Ocean associated with warmer water 3) Increase in sea surface temperatures and destruction of coral reefs in the eastern Pacific Ocean

Surface ocean currents:

1) form large rotating gyres in the major ocean basins 2) are influenced by Coriolis effect 3) are driven by winds

Of the following locations, where would upwelling be expected to occur?

1)Where there is a sharp bend in a coastline 2)Where there is a shallowly submerged sea floor obstruction, such as a table mount 3)In areas of offshore winds 4)In areas of diverging surface currents, such as along the equator

The actual movement of surface water due to Ekman transport in the Northern Hemisphere is about __________.

45° to the right of wind direction

Which of the following statements is most accurate about tsunami hazards and the number of people at risk?

A low tsunami hazard and a high number of people at risk are present along the coast of the eastern United States.

Which of the following statements about earthquakes and tsunami hazards is most accurate?

A relatively high number of earthquakes and the greatest tsunami hazard occur along the western coast of South America.

Which body of water is shown to have the greatest amount of coastal pollution?

Baltic Sea

The Gulf Stream transports warm water into the __________.

North America

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

A deep and powerful southward subsurface current that flows under the Gulf Stream in the North Atlantic is the __________.

North Atlantic Deep Water

The largest of the great ocean surface currents is the __________

West Wind Drift

In the Northern Hemisphere, the Ekman spiral moves layers of water to the _____ of the wind direction and Ekman transport (the overall direction of water movement) is to the _____.

right; right

video with reg and diet soda. As shown in the video, the regular version of the item _____ and the diet version _____.

sank; floated

High amounts of _____ caused one of the items to _____.

sugar; sink

cool ocean currents:

generally flow from high latitudes towards the equator

Compared to an eastern boundary current in a gyre, which of the following statements is true for a western boundary current?

All of the above statements are true of western boundary currents

During winter months, monsoon winds over the Indian Ocean:

flow from land to sean and are dry

Indian Ocean currents that are generated by seasonal changes in weather patterns are the __________ and __________ Currents.

Somali/Southwest Monsoon

The West Wind Drift (Antarctic Circumpolar Current) is a part of which of the following subtropical gyres?

South Atlantic Subtropical Gyre South Pacific Subtropical Gyre Indian Ocean Subtropical Gyre

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?

The eastern coast of Australia would be experiencing unusually dry weather

Of the following statements about subtropical gyres, which is/are true?

The western boundary current of all subtropical gyres is intensified (it is fast, narrow, and deep). Globally, there are five subtropical gyres. There are four main surface currents in each subtropical gyre The centers of all subtropical gyres are associated with high atmospheric pressure. The rotation of each subtropical gyre causes a "hill" of water to pile up within it.

__________ is caused by density changes near the poles and the equator

Thermohaline circulation

Why does upwelling occur along the west coast of South America under normal conditions?

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

Western intensification causes

a steeper slope of surface water in the western section of the gyre as compare to the eastern section of the gyre. equatorial countercurrents. very swift western boundary currents. the center of the gyre to be shift to the west. All of the above statements are the result of westward intensification.

To what depth in the ocean does the Ekman spiral extend?

about 100 meters (330 feet)

warm ocean currents:

are warmer than the surrounding water

Compared to western boundary currents, eastern boundary currents are

broad and slow

Canary Current

cold current, northern hemisphere, temperate latitudes

The coastlines with the greatest tsunami hazard are most commonly associated with what type of plate boundary?

convergent

The loss of heat from the ocean surface, resulting in a lowered temperature, causes ocean water to become __________.

denser

The worldwide effects of El Niño include all of the following except:

drought in the U.S. Gulf coastal states

Equatorial currents that are part of the subtropical gyres flow ___. Equatorial counter currents between the gyres flow ___ .

east to west; west to east

Which direction do ocean currents in the South Pacific move under El Niño conditions?

eastward

Deep ocean water does not travel across the equator

false

Surface ocean currents are vertical currents in the water column that are density-driven

false

The densest ocean water is North Atlantic Deep Water

false

A large system of rotating ocean currents, usually driven by the major wind belts, is called a(n) __________.

gyre

freezing seawater at ___________ leading to increases in salinity and density

high latitudes

Compared to Antarctic Bottom Water, North Atlantic Deep Water is:

lower in oxygen

What is the overall effect of the stronger than normal trade winds typical of La Niña conditions?

lowering of the South Pacific ocean temperature from normal conditions

Fluctuations in the flow of the Gulf Stream current result in curving loops of water known as __________.

meanders

Kuroshio Current

northern hemisphere, temperate latitudes, warm current

the subtropical gyres:

play a large role in climate

An indirect method of measuring ocean current is the use of __________.

radar altimeters

Sources of deep water in the ocean include all of the following except:

subtropical convergences

Deep ocean current movement is also known as __________.

thermohaline flow

In the southern hemisphere, the direction of Ekman transport is always:

to the left of the wind direction

Equatorial currents are driven by the:

trade winds

Deep ocean currents often move cold, dense water away from the poles.

true

Downwelling may be the result of winds blowing parallel to a coastline or the convergence of surface currents.

true

Dynamic topography can be used to determine current direction and velocity.

true

In the northern hemisphere, Ekman transport pushes surface water to the right of the wind direction

true

Monsoons are seasonal pressure systems that develop at lower latitudes over continents, which cause changes in seasonal winds and precipitation patterns.

true

Western boundary currents such as the Gulf Stream transport warm water from the tropics towards higher latitudes

true