Deck 10: The Restless Ocean

Question 1

Fetch is ________.

A)a method of shoreline erosion control
B)the distance between the trough of a wave and the still water level
C)the circular pattern made by water particles when a wave passes
D)the distance over which the wind blows over open water

Answer 1

D

Question 2

________ are huge circular-moving current systems that dominate the surface of the ocean within an ocean basin.

A)Tombolos
B)Gyres
C)Coriolis
D)Upwellings

Answer 2

B

Question 3

The center of each of Earth's five major gyres is found at about ________ latitude.

A)0° (the equator)
B)30°
C)60°
D)90°

Answer 3

B

Question 4

Which of the following is an example of "hard stabilization" designed to prevent or retard shoreline erosion?

A)seawall
B)groin
C)breakwater
D)all of the above

Question 5

Which of the following shoreline features is a result of erosion?

A)spit
B)estuary
C)tombolo
D)sea arch

Question 6

Waves begin to "feel bottom" when the depth of water is ________.

A)equal to one-half the wavelength
B)equal to the wavelength
C)twice as great as the wavelength
D)equal to the fetch

Question 7

One result of wave refraction is that wave energy is concentrated ________.

A)on headlands projecting into the water
B)on tombolos
C)in bays, coves, and other recessed areas between headlands
D)on spits

Question 8

Chesapeake Bay and Delaware Bay are ________.

A)associated with a submergent coast
B)former river valleys that were flooded by a rise in sea level
C)excellent examples of large estuaries
D)all of the above

Question 9

One disadvantage of beach nourishment as compared to hard stabilization is ________.

A)beach nourishment is permanent
B)hard stabilization may increase erosion
C)beach nourishment is expensive
D)hard stabilization makes the coast more scenic for recreation

Question 10

Which of the following shoreline features is a result of deposition?

A)barrier island
B)sea stack
C)wave-cut platform
D)marine terrace

Question 11

The height, length, and period of a wave depend upon ________.

A)the length of time the wind has blown
B)the wind speed
C)the fetch
D)all of the above

Question 12

Longshore currents and beach drift ________.

A)move in opposite directions
B)both have net movement that is parallel to the shore
C)are oriented at 90° to each other
D)are found only in deep water, and never close to the shore

Question 13

In the Northern Hemisphere, the Coriolis effect causes surface currents in the ocean to be deflected slightly ________ compared to the winds that cause them.

A)to the left
B)to the right
C)to the north
D)to the south

Question 14

The daily tidal range is of the least magnitude during ________.

A)the daytime
B)spring tides
C)neap tides
D)slack water

Question 15

Waves approaching a beach at an oblique angle ________.

A)cause beach drift
B)cause hard stabilization
C)cause coasts to switch from submergence to emergence
D)make tides rise and fall

Question 16

When waves reach shallow water they tend to be ________, which makes them become parallel to the shore.

A)reflected
B)refracted
C)translated
D)eroded

Question 17

You visit a coastal area for the first time. You note the presence of marine terraces, sea stacks, and sea arches. Based on these features, the area is likely to be ________.

A)experiencing a spring tide
B)in need of beach nourishment
C)an emergent coast
D)a submergent coast

Question 18

Which of the following is correct regarding a wave in the open ocean?

A)Water particles move vertically in circular orbital motion.
B)Water particles move in a straight line, in the same direction that the wave is moving.
C)Water particles move in a straight line, in the opposite direction that the wave is moving.
D)Water particles move in an almost circular horizontal path.

Question 19

The energy that drives surface ocean currents such as the Gulf Stream comes from ________.

A)the Coriolis effect
B)salinity variations
C)temperature differences
D)prevailing wind patterns

Question 20

Examine the figure. Of the three forms of hard stabilization illustrated here, which one is the groin?

A)A
B)B
C)C
D)none of these is a groin

Question 21

Beach drift and longshore currents only develop when waves' direction of approach is perpendicular to the shoreline.

Question 22

When viewed from above, the North Atlantic Gyre displays a clockwise sense of motion.

Question 23

A ________ is an isolated remnant of bedrock standing above a wave-cut platform.

A)sea arch
B)sea stack
C)marine terrace
D)wave-cut cliff

Question 24

To measure wave period, the best tool to use would be a ruler.

Question 25

As the tide rises, water flows in toward the shore as the ebb tide.

Question 26

Groins are constructed for the purpose of maintaining or widening beaches that are losing sand.

Question 27

Although the Sun influences the tides, its gravitational effect is considerably less than the effect of the Moon.

Question 28

Waves begin to "feel bottom" at a depth that is about one-half their wavelength.

Question 29

Large estuaries are more common on a(n)________ coastline.

A)emergent
B)submergent
C)stable
D)eroding

Question 30

Marine terraces in coastal California are evidence that this coastal area is emergent.

Question 31

Examine the satellite view of chlorophyll concentrations in the southern Atlantic Ocean along the southwest coast of Africa (the nations of Namibia and South Africa). Which of the following statements offers the best explanation for the observed pattern(s)?

A)This is an area of downwelling, where water is sinking due to the higher density it gains when sea ice forms and salinity increases.
B)This is an area of upwelling, where nutrient-rich water is rising due to winds blowing over the ocean's surface.
C)This is an area of shallow water and waves breaking as they "feel bottom."
D)The coast is a "dead zone," an area of very low biological activity.

Question 32

The largest daily tidal range occurs in association with spring tides.

Question 33

A baymouth bar is an example of "hard stabilization," a feature constructed by people to control wave erosion.

Question 34

Cold currents can trigger desertification because they stabilize air that might otherwise rise and generate precipitation.

Question 35

Spring tides occur in conjunction with the full Moon or the new Moon.

Question 36

Deep ocean currents are driven by thermohaline circulation, rather than prevailing winds.

Question 37

Tidal flats are submerged during ebb tide.

Question 38

Erosional retreat of a(n)________ leads to enlargement and extension of a wave-cut platform in the inland direction.

A)wave-cut cliff
B)marine terrace
C)sea arch
D)spit

Question 39

Barrier islands are common on the Gulf Coast but rare or absent along the Pacific Coast of the United States.

Question 40

Upwelling, the rising of water from deeper layers of the ocean, is a wind-induced movement that brings ________ water to the surface.

A)cold, nutrient-rich
B)cold, nutrient-poor
C)warm, nutrient-rich
D)warm, nutrient-poor

Question 41

Match the items in the first column with the correct descriptions in the second column.

A)building structures along the coastline to prevent movement of sand
B)a deposit of sediment resulting from a flood current passing through an inlet
C)like the Atlantic coast of the United States, an area of sea level rise relative to the land
D)the amount of time it takes for two wave crests to pass the same point
E)like the Pacific coast of the United States, an area of land uplift relative to sea level
F)the sawing and grinding action of water armed with rock fragments
G)pumping sand onto the beach from some other area, temporarily replenishing the sediment supply
H)the distance from one wave crest to the next
1)abrasion
2)wave period
3)wavelength
4)hard stabilization
5)beach nourishment
6)submergent
7)emergent
8)tidal delta

Question 42

________ are low-lying zones that are alternately covered by water during flood tide and exposed following ebb tide.

Question 43

________ is the rising of cold water from deeper layers to replace warmer surface water.

Question 44

A shoreline is a(n)________, a common boundary where different parts of a system interact.

Question 45

Because deep ocean circulation is driven largely by variations in water temperature and salinity, it is also called ________ circulation.

Question 46

Currents within the surf zone that flow parallel to the shore are known as ________ currents.

Question 47

Examine the map shown in the figure. If you were to go swimming in the ocean along this shoreline, which way would the longshore current carry you? ________

Question 48

Does this photograph show a tombolo, a barrier island, a sea arch, or a marine terrace? ________

Question 49

Examine the figure. Identify and label each of the lettered locations with the name of the shoreline feature shown there.

Question 50

The ________ is the distance the wind has traveled across open water.

Question 51

A(n)________ is a place where fresh and salt water mix, such as a drowned river valley along a submergent coast.

Question 52

Examine the figure.
Identify the type and describe the tidal patterns observed over the course of a day in three U.S. cities: San Francisco, California (SF), New Orleans, Louisiana (NO), and New York, New York (NY).

Question 53

If uplift of the land occurs, a wave-cut platform may become a new ________.

Question 54

Breakwaters, sea walls, and groins are all examples of ________.

Question 55

Examine the figure and use the information provided there to explain the different temperature trends seen in Arica and Rio de Janeiro.

Question 56

Describe some of the options available to people when it comes to coping with erosion along shorelines.

Question 57

If a spit grows as it is deposited, and extends completely across the former mouth of an estuary, separating it from the open sea, it has become a(n)________.

Question 58

As a deep-water wave enters shallow water, the part of the wave in the most shallow water slows down. The deeper-water portion of the wave crest keeps moving at a relatively rapid speed. This wave refraction causes the entire wave crest to progressively rotate toward being ________ with the shoreline.

Question 59

________ are large circular-moving currents of water within an ocean basin.

Question 60

Turbulent water created by breaking waves is known as ________.

Question 61

Examine the map shown here. You are considering buying property "C" on this stretch of coastline. Before signing the contract on the property, you hear that the owners of property "B" are considering building a groin like their neighbors recently did on property "A." Should you reconsider your purchase? Explain.

Question 62

Climate change is particularly acute in the Arctic. Some scientists are concerned about the melting of the Greenland ice sheet because the extra water will cause sea level to rise around the globe. However, another concern is related to the thermohaline "conveyer belt" of ocean circulation. How might the melting of the Greenland ice sheet cause changes to that pattern of currents?

Question 63

Fossil fuels are a cheap way to make electricity, but burning them generates greenhouse gases. Nuclear power produces a lot of low-carbon energy, but nuclear accidents may release dangerous radioactivity. Windmills generate electricity from the movement of air currents, but the wind doesn't always blow. In light of all these "down sides" to energy production, consider how you might harness longshore currents to produce electricity. Describe your plan in detail, and sketch out how it would work. What might be some of the potential drawbacks to your plan?