oceanography ch.7 quiz

Of the following statements about deep-ocean currents, which are true?

-Deep ocean currents are important regulators of global climate -deep ocean currents are initiated by downwelling of cold, dense water near Antarctica in the north atlantic ocean -deep ocean circulation is often referred to as thermohaline flow -deep ocean currents contain water that is high in oxygen -the volume of water involved in the downward movement of deep ocean water currents is equal to the flow of 100 Amazon-sized rivers

Of the following gyres, which one(s) flow in a counterclockwise direction?

-south atlantic subtropical gyre -indian ocean subtropical gyre -northern hemisphere subpolar gyres -south pacific subtropical gyre

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

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

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

-where there is a sharp bend in a coastline -where there is a shallowly submerged sea floor obstruction, such as a tablemount -in areas of diverging surface currents,such as along the equator -in areas of offshore winds

To produce a surface current of 1.6 knots in the open ocean, a steady wind of _____ knots would be required.

80

A. Agulhas Current B. Benguela Current C. California Current D. Canary Current E. West Australian Current

A.

A. California Current B. Canary Current C. Gulf Stream D. North Atlantic Current E. North Equatorial Current in the Atlantic Ocean

A. Calfornia Current

The arrangement of water masses in the southern Atlantic Ocean from the surface to the bottom is:

Antarctic Intermediate Water, North Atlantic Deep Water, Antarctic Bottom Water.

Of the following currents, which ones are parts of the South Atlantic Subtropical Gyre?

Benguela Current brazil current south equatorial current west wind drift

Which of the following is a western boundary current?

Brazil Current

A. thermohaline circulation B. density-driven circulation C. Antarctic Bottom Water D. Kuroshio Current E. North Atlantic Deep Wate

D. Kuroshio current

A. Australian drought B. decreased fish stock in coastal Peru C. flooding rains in southeastern U.S. D. Peruvian upwelling stops E. strong trade winds

E. strong trade winds

The Gulf Stream moves water away from the equator; the Benguela Current moves some of this same water back toward the equator.

False

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.

Identify the mismatched pair from the choices below.

Labrador Current, Humboldt Current

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

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

Which of the following statements is true of surface ocean currents?

Surface currents form circular patterns in the major ocean basins called "gyres."

The main current in Antarctic waters is the Antarctic Circumpolar Current, also called the West Wind Drift.

True

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.

The thermocline is _________________.

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

Western intensification causes:

all of the above

Compared to western boundary currents, eastern boundary currents are:

broad and slow

When a meander from the Gulf Stream pinches off and isolates a body of water within the North Atlantic gyre, the body of water is called a:

cold core ring

Downwelling can result from __________.

converging surface currents

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

denser

Thermohaline circulation is driven by:

density differences

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

drought in the US Gulf coastal states

Surface currents affect about 90% of the world's ocean water.

false

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

The densest ocean water is North Atlantic Deep Water.

false

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. they are wind driven

During winter months, monsoon winds over the Indian Ocean:

flow from land to sea and are dry

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

geostrophic circulation

Which of the following two factors cause geostrophic circulation within a gyre?

gravity and the Coriolis effect

Deep-water circulation brings oxygen from the surface to the deep ocean because of:

greater dissolution of oxygen in colder water than warmer water

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

Which of the following is not an eastern boundary current?

gulf stream

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

gyre

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

north Atlantic deep water

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

radar altimeters

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

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

somali/southwest monsoon

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

subtropical convergences

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.

The El Niño Southern Oscillation can best be described as:

the relationship between sea surface temperature and changing atmospheric pressure.

The Ekman spiral is caused by:

the wind and the Coriolis effect

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

A Doppler flow meter is a scientific instrument used to measure current flow rates.

true

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

true

Deep ocean water can be enriched in oxygen when it is mixed with surface water.

true

Deep ocean water masses have characteristic temperatures and salinities.

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

The five subtropical gyres exhibit geostrophic flow, related to pressure gradients, friction, and the Coriolis effect.

true

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

upwelling

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

warmer water increased current velocity narrower current deeper current

The largest of the great ocean surface currents is the __________.

west wind drift

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

west wind drift north pacific current equatorial counter current

Warm core rings and cold core rings are associated with __________.

western boundary currents

Upwelling occurs in all the following locations except :

where deep-ocean currents are formed

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

wind; the Coriolis effect and land