Oceanography Ch. 7 Exam

The unit of measurement used to describe the rate at which a volume of ocean water moves in a current
is a(n) __________.
(a) calorie
(b) ft/s
2
(c) km/h
(d) ml/g
(e) Sverdrup

Dynamic topography can be used to compute current direction and velocity.
(a) True
(b) False

The ultimate source of most of the energy for ocean currents is the ___________.
(a) weather
(b) wind
(c) sun
(d) tides

The immediate source of most of the energy for ocean currents is the ___________.
(a) weather
(b) wind
(c) the sun
(d) the tides

A system of four currents completing a flow circuit around the periphery of an ocean basin is
collectively called a ___________.
(a) cell
(b) Carroll pattern
(c) gyre
(d) gimble
(e) wabe

Most surface currents are driven by the ___________.
(a) Earth’s rotation
(b) Magnetic fields
(c) Aurora borealis
(d) wind
(e) salinity differences of surface waters

The Earth’s rotation influences currents by a force (or acceleration, to be correct) known as the
___________.
(a) Franklin rotation
(b) geostrophism
(c) gyral nutation
(d) Coriolis effect

Currents tend to move in great ___________ patterns in the northern hemisphere.
(a) irregular
(b) counterclockwise
(c) clockwise
(d) random

Currents are named for the direction ___________.
(a) in which they are going
(b) from which they are coming

The circular pattern of surface water currents is called a gyre.
(a) True
(b) False

Geostrophic circulation is within a gyre driven by __________.
(a) density
(b) gravity
(c) temperature
(d) the Coriolis effect
(e) wind

Westward intensification causes __________.
(a) a steeper slope of surface water in the western section of the gyre as compare to the eastern
section of the gyre
(b) equatorial countercurrents
(c) the center of the gyre to be shift to the west
(d) very swift western boundary currents
(e) All of the above statements are the result of westward intensification

Movement of ocean currents by gravity and modified by the Coriolis force is called __________.
(a) Ekman transport
(b) geostrophic flow
(c) upwelling
(d) downwelling

Transport of water to the left or right of the wind direction is called __________.
(a) Ekman transport
(b) geostrophic flow
(c) upwelling
(d) downwelling

Equatorial currents are driven by the __________.
(a) Coriolis force
(b) density
(c) Ekman transport
(d) trade winds
(e) westerlies

Surface ocean circulation is driven primarily by _______ and modified by ________.
(a) density differences; the Coriolis effect and land
(b) density differences; differences in salinity and temperature
(c) latitude; differences in salinity and land
(d) wind; the Coriolis effect and land
(e) wind; gravity and density

Convection cells driven by the relatively weak winds near the center of gyres are called __________.
(a) Ekman transport
(b) geostrophic circulation
(c) Langmuir circulation
(d) thermohaline circulation
(e) upwelling

An eastern boundary current is narrow and swift.
(a) True
(b) False

Western boundary currents can have well-defined edges.
(a) True
(b) False

Geostrophic flow is a dynamic balance between ___________ and ___________.
(a) wind; gravity
(b) gyres; continental masses
(c) north polar magnetic fields; south polar magnetic fields
(d) Coriolis deflection; pressure gradient

Geostrophic gyres can be described by which of the following statements?
(a) They are “turned by the Earth”.
(b) They depend on Coriolis effect and the position of continental land masses for their direction.
(c) They form gyres around the perimeters of ocean basins.
(d) They are physically large phenomena.
(e) All of the above are true.

Currents that result from a balance between pressure gradient and Coriolis effect are termed
___________ currents.
(a) Coriolis
(b) Density
(c) Geostrophic
(d) Seismic
(e) Internal

The Ekman spiral is driven by__________.
(a) density differences in the water column
(b) gravity
(c) the Coriolis effect
(d) the pycnocline
(e) wind

Which type of flow works in opposition to Ekman transport in a gyre?
(a) counter-current circulation
(b) density-driven circulation
(c) geostrophic circulation
(d) Langmuir circulation
(e) thermohaline circulation

In the northern hemisphere, Ekman transport pushes surface water to the right of the wind direction.
(a) True
(b) False

The amount of seawater water flowing in the geostrophic currents of the world ocean is approximately
equal to the total amount of water flowing in all the Earth’s fresh water rivers.
(a) True
(b) False

Compared to an eastern boundary current in a gyre, which of the following statements is true for a
western boundary current?
(a) deeper current
(b) increased current velocity
(c) intensification in subtropical latitudes
(d) narrower current
(e) All of the above statements are true of western boundary currents

Compared to a western boundary current, which of the following statements is true for an eastern
boundary current?
(a) Eastern boundary currents are broad and deep.
(b) Eastern boundary currents are broad and slow.
(c) Eastern boundary currents are deep and swift.
(d) Eastern boundary currents are narrow and deep.
(e) Eastern boundary currents are shallow and swift.

Replacement of water coming from the bottom to the top of the water column is called __________.
(a) Ekman transport
(b) geostrophic flow
(c) upwelling
(d) downwelling

Replacement of water coming from the top to the bottom of the water column is called __________.
(a) Ekman transport
(b) geostrophic flow
(c) upwelling
(d) downwelling

When near-surface water is moved offshore by Ekman transport, water from below replaces it in a
process known as ___________.
(a) upwelling
(b) downwelling
(c) Langmuir circulation
(d) Franklin eddies
(e) occlusion

Downwelling may be the result of winds blowing parallel to a coastline.
(a) True
(b) False

Wind moving from the north along the California coast causes water moving along the coast to
___________.
(a) move south
(b) move toward shore (east)
(c) move away from shore (west)
(d) move north

When winds blow parallel to the coast, such that Ekman transport drives water against the land,
surface water sinks in the process known as ___________.
(a) upwelling
(b) downwelling
(c) Langmuir circulation
(d) Franklin eddies
(e) occlusion

Surface waters are pushed away from land and replaced by nutrient-rich bottom water through
__________.
(a) convergence
(b) downwelling
(c) land breezes
(d) sea breezes
(e) upwelling

Strong upwelling occurs in all of the following except __________.
(a) between the North and South Equatorial Currents
(b) in areas of surface current divergence
(c) in the area surrounding the Galapagos Islands
(d) where deep ocean water currents are formed
(e) where water is constantly pushed away from a coastline

El Niño results due to an interruption of flow of the __________ Current(s) in the Pacific.
(a) Kuroshio
(b) Humboldt and Equatorial
(c) Canary and North Atlantic
(d) West Wind Drift
(e) Arctic

During an El Niño event, ___________.
(a) the trade winds strengthen
(b) the central eastern Pacific ocean becomes cooler
(c) sea level falls in the central eastern Pacific ocean
(d) a strong equatorial countercurrent develops in the Pacific
(e) the Peru Current strengthens

Which of these is generally not an El Niño effect?
(a) A rise in the sea level off the coasts of the American Continents.
(b) An increase in ocean surface temperature in the eastern Pacific.
(c) An increase in rainfall in west coastal countries or states of the American continents.
(d) An often catastrophic decrease in the commercial fisheries of the affected countries.
(e) A decline in the exotic species of fish and other forms of marine life in the affected waters.

The worldwide effect of El Niño includes all of the following except __________.
(a) coral reef deaths in the Pacific Ocean
(b) crop failure in the Philippines
(c) drought in the US Gulf coastal states
(d) increased Pacific cyclone activity
(e) water shortages in Sri Lanka

The El Niño Southern Oscillation can best be described as __________.
(a) relative changes between two different atmospheric pressure systems
(b) the relationship between sea surface temperature and high altitude pressure
(c) tidal differences between coastal Peru and Darwin, Australia
(d) variation in wind speed over the Pacific Ocean
(e) wind speed and wind direction differences along the equator

The El Niño weather pattern is associated with __________.
(a) about a 0.5 meter difference in sea surface height between Tahiti and Darwin, Australia
(b) cold, nutrient-rich water close to the sea surface near the coast of Peru
(c) drought and fires in Australia
(d) high pressure sitting over coastal Peru
(e) trade winds blowing east to west

The first person to comprehend the worldwide pattern of ocean surface currents was probably
___________.
(a) Benjamin Franklin
(b) Vagn Ekman
(c) Fridtjof Nansen
(d) Matthew Maury
(e) Henry Stommel

The only ocean current that continues in an uninterrupted circle around the circumference of the Earth
without encountering land is the ___________.
(a) Gulf Stream
(b) Kuroshio, or Japan, Current
(c) West Wind Drift or Antarctic Circumpolar Current
(d) Canary Current

Which ocean surface current carries the greatest volume of water?
(a) The Kuroshio (or Japan) Current
(b) The North Equatorial Current in the Pacific
(c) The South Equatorial Current in the Pacific
(d) The West Wind Drift
(e) The Canary Current

Generally the fastest and deepest ocean currents are ___________.
(a) northern boundary currents
(b) eastern boundary currents
(c) western boundary currents
(d) southern boundary currents

The characteristics of western boundary currents are a result of ___________.
(a) Coriolis deflection.
(b) higher wind speeds on the western edge of oceans.
(c) deeper continental shelf areas on the western edge of oceans.
(d) greater freshwater runoff from the adjacent land masses, which stabilizes the water column.
(e) the rotation of the earth, which presses water against the western edge of the ocean basins.

Benjamin Franklin was the first person to recognize the extent of the ___________ and to publish a
navigational chart of it.
(a) North Equatorial Current.
(b) Gulf Stream.
(c) El Niño.
(d) Kuroshio Current.
(e) Canary Current.

The Gulf Stream moves water away from the equator; the Benguela Current moves some of this same water back toward the equator.
(a) True
(b) False

Meander loops that pinch off from the main axis of the Gulf Stream are called ___________.
(a) oxbows
(b) meander scars
(c) rings
(d) wanderers
(e) detached basins

Britain’s weather is ___________ than would be expected at that latitude because of the influence of
surface currents.
(a) colder
(b) drier
(c) less humid
(d) warmer and wetter

Which of the following is a western boundary current?
(a) Benguela Current
(b) Brazil Current
(c) Canary Current
(d) California Current
(e) Peru Current

Which of the following is not an eastern boundary current?
(a) California Current
(b) Canary Current
(c) Gulf Stream
(d) Peru Current
(e) W. Australian Current

Which current within a Northern Hemisphere gyre would you expect to have the lowest salinity and
temperature?
(a) a western boundary current
(b) an eastern boundary current
(c) a southern boundary current
(d) a northern boundary current
(e) All of these currents would be about equal in temperature and salinity.

San Francisco’s characteristic cold and foggy weather is caused by a ___________.
(a) cold eastern boundary current
(b) warm eastern boundary current
(c) cold western boundary current
(d) warm western boundary current

The California Current in the northeastern Pacific Ocean is an example of a __________ current.
(a) warm-water, western boundary
(b) warm-water, eastern boundary
(c) transverse
(d) cold-water, western boundary
(e) cold-water, eastern boundary

The Kuroshio Current in the northwestern Pacific Ocean is an example of a __________ current.
(a) warm-water, western boundary
(b) warm-water, eastern boundary
(c) transverse
(d) cold-water, western boundary
(e) cold-water, eastern boundary

The Gulf Stream in the northwestern Atlantic Ocean is an example of a __________ current.
(a) warm-water, western boundary
(b) warm-water, eastern boundary
(c) transverse
(d) cold-water, western boundary
(e) cold-water, eastern boundary

The Canary Current in the northeastern Atlantic Ocean is an example of a __________ current.
(a) warm-water, western boundary
(b) warm-water, eastern boundary
(c) transverse
(d) cold-water, western boundary
(e) cold-water, eastern boundary

The largest current by volume in the oceans is the Antarctic Circumpolar Current.
(a) True
(b) False

Which of the following is true of surface water circulation near Antarctica?
(a) A gyre is formed here.
(b) Two circumpolar currents dominate it, one current that moves water to the east and one
current that moves water to the west.
(c) It is dominated by water flow directly away from the polar region toward the north.
(d) The surface ocean has no strong currents.
(e) The polar easterlies drive the circulation of water around the Antarctic continent.

The Sargasso Sea is located in the __________.
(a) Arctic Ocean
(b) Indian Ocean
(c) North Atlantic Ocean
(d) North Pacific Ocean
(e) South Atlantic Ocean

When a meander from the Gulf Stream pinches off and isolates a body of water within the center of
the North Atlantic gyre, the body of water is called a __________.
(a) cold-core ring
(b) cyclonic circulation
(c) geostrophic circulation
(d) Langmuir cell
(e) warm-core ring

Identify the mismatched pair.
(a) Agulhas Current, West Australia Current
(b) Brazil Current , Benguela Current
(c) Canary Current, Gulf Stream
(d) Kuroshio Current, California Current
(e) Labrador Current, Humboldt Current

During winter months, monsoon winds over the Indian Ocean __________.
(a) flow from land to sea and are dry
(b) flow from land to sea and are wet
(c) flow from sea to land and are dry
(d) flow from sea to land and are wet
(e) the direction of airflow is unchanged but precipitation increases

Thermohaline circulation patterns are caused by variations in ___________.
(a) evaporation
(b) precipitation
(c) land runoff
(d) heat exchange with the atmosphere
(e) all of the above

The densest water in ocean currents is the ___________.
(a) warmest and saltiest
(b) coldest and saltiest
(c) warmest and freshest
(d) coldest and freshest

Thermohaline circulation is the dominant type of water flow in the ocean.
(a) True
(b) False

The main force driving thermohaline circulation is ___________.
(a) wind
(b) Coriolis effect
(c) gravity
(d) electromagnetic attraction

Density of water is a function of its ___________, ___________, and ___________.
(a) chemical content; distance from land; turbidity
(b) distance from land; depth; rate of flow
(c) rate of flow; turbidity; resistance to wind drag
(d) temperature; salinity; pressure

As the temperature of water increases, its density ___________.
(a) increases
(b) decreases

As the salinity of water increases, its density ___________.
(a) increases
(b) decreases

Thermohaline currents tend to flow very ___________.
(a) rapidly
(b) slowly
(c) sporadically

Deep currents are horizontal and rarely move vertically.
(a) True
(b) False

Most deep bottom water forms___________.
(a) near the ocean floor in the arctic
(b) near the ocean floor in the Antarctic
(c) near the ocean surface in the arctic
(d) near the ocean surface in the Antarctic

Deep ocean water masses have characteristic temperatures and salinities.
(a) True
(b) False

All deep water in ocean basins originates in the Atlantic Ocean.
(a) True
(b) False

Deep water circulation in the Pacific Ocean is influenced by __________.
(a) extreme cooling and the formation of Pacific Bottom Water
(b) hydrothermal vents from the East Pacific Rise
(c) sea ice formation and resulting increased salinity of surface water in the south Pacific
(d) the size of the Pacific basin
(e) the Southern Oscillation

Deep ocean water in the Indian Ocean includes Red Sea water which has __________.
(a) high salinity and low oxygen
(b) high salinity and low temperature
(c) low salinity and low oxygen
(d) low temperature and high oxygen
(e) low temperature and low salinity

The source of some deep ocean water masses can be identified by the amount of dissolved oxygen in
the water mass.
(a) True
(b) False

Deep ocean water does not travel across the equator.
(a) True
(b) False

Thermohaline circulation is wind-driven.
(a) True
(b) False

Deep ocean currents often move cold, dense water away from the poles.
(a) True
(b) False

Compared to Antarctic Bottom Water, North Atlantic Deep Water is __________.
(a) colder
(b) denser
(c) higher in nutrients
(d) higher in salinity
(e) lower in oxygen

The location where water flow uninterrupted between the Pacific, the Atlantic, and the Indian Oceans
is __________.
(a) in the Arctic Ocean
(b) in the Southern Ocean
(c) near Alaska
(d) near the equator
(e) This does not occur

The arrangement of water masses in the southern Atlantic Ocean from the surface to the bottom is
__________.
(a) Antarctic Bottom Water, Antarctic Intermediate Water, North Atlantic Deep Water.
(b) Antarctic Intermediate Water, Antarctic Bottom Water, North Atlantic Deep Water.
(c) Antarctic Intermediate Water, North Atlantic Deep Water, Antarctic Bottom Water.
(d) North Atlantic Deep Water, Antarctic Bottom Water, Antarctic Intermediate Water.
(e) North Atlantic Deep Water, Antarctic Intermediate Water, Antarctic Bottom Water.

Scientists have concluded that deep Pacific Ocean water is old is due to its low __________.
(a) density
(b) nutrient levels
(c) oxygen levels
(d) salinity
(e) temperature

Subsurface currents are driven mainly by ___________.
(a) wind
(b) the rotation of the Earth
(c) density differences
(d) solar storms
(e) wind drag

Countercurrents and undercurrents generally move ___________ than the surface current above, and
in __________ direction.
(a) faster … the same
(b) faster … the opposite
(c) slower … the same
(d) slower … the opposite

Deep ocean water generally has high amounts of __________.
(a) dissolved organic matter
(b) nutrients only
(c) oxygen only
(d) nutrients and oxygen
(e) suspended solids