Deck 11: Coastal Processes

Question 1

Beach erosion on Great Lakes shorelines is exacerbated by

A)periodic high lake levels
B)damming of rivers
C)construction of expensive homes on lake bluffs
D)removal of foredunes in the barrier island systems

Answer 1

A

Question 2

Why does seacliff erosion occur at high rates in some areas?

A)Because wave action is particularly strong on coastlines with seacliffs.
B)Seacliffs tend to be made of very weak Earth materials.
C)Littoral transport removes Earth materials from the seacliffs.
D)The seacliff may be exposed to both wave action and terrestrial mass wasting processes.

Answer 2

D

Question 3

Coastal landscapes are capable of rapid change because continental and oceanic processes converge there.

Answer 3

True

Question 4

What is the principal goal of beach nourishment?

A)to augment the sand supply so that engineered structures work more efficiently
B)to maintain a positive beach budget and alleviate the need for engineered structures
C)to keep jetties from accumulating so much sand that they fill in river channels
D)to eliminate littoral transport

Question 5

How might global warming exacerbate coastal hazards?

A)Global warming will likely be accompanied by sea level rise.
B)Warmer water is more highly erosive on coastlines.
C)Ocean currents will be stronger in a warmer world.
D)Under warmer conditions, waves are likely to be substantially larger.

Question 6

Which of the following does not influence wave size?

A)wind velocity
B)wind duration
C)wind fetch
D)wind temperature

Question 7

The Cape Hatteras lighthouse was moved inland because a major storm damaged it in 1994.

Question 8

Why does ocean swell tend to consist of waves of similar sizes?

A)Swell is controlled by water depth.
B)Swell is controlled by wind speed, and all of the waves that comprise swell arise from the same wind cell.
C)Wavelength is similar for all ocean waves.
D)Waves far from their storm source tend to be sorted into groups of similar waves.

Question 9

Ocean swell consists of a chaotic distribution of wave heights and lengths.

Question 10

As waves enter the coastal zone, wavelengths shorten and wave heights increase.

Question 11

Why are the impacts of coastal hazards so great?

A)because coastal erosion extends far inland
B)because coastal hazards are particularly intense natural hazards
C)because many populated areas are located near the coasts
D)because they are high magnitude/low frequency hazards

Question 12

Refraction occurs because waves speed up as they reach the shallower water near the beach.

Question 13

As waves enter shallow water

A)wavelength decreases and wave height increases
B)wavelength increases and wave height increases
C)wavelength decreases and wave height decreases
D)wavelength increases and wave height decreases

Question 14

Why do waves expend so much energy on a rocky headland?

A)Waves reflect off the headland and amplify the incoming waves.
B)Wave velocity is greater on headlands than on beaches.
C)Waves refract toward the headland on both sides.
D)Headlands tend to have deeper water surrounding them, so the waves are higher.

Question 15

What is the main drawback of seawalls?

A)They tend not to protect the seacliff very well.
B)They stop the longshore transport of sand.
C)They reflect wave energy back across the beach and cause erosion.
D)They trap sand, forcing the ocean around the beach, where it erodes intensively.

Question 16

What adverse effect do groins and jetties both have on coastal erosion?

A)They stop littoral transport of sand and starve down-drift areas of sand.
B)They reflect waves across the beach.
C)They cause the waves striking the structure to increase in height and erosive power.
D)They rob the waves of their energy to transport sand.

Question 17

Why does river damming sometimes contribute to coastal erosion?

A)The supply of sediment to beaches is shut off.
B)The supply of water to the longshore current is reduced.
C)The channel between jetties tends to become clogged with sand.
D)The reservoirs occasionally flood through a distributary channel, eroding the beach.

Question 18

Hurricanes in the tropical Atlantic Ocean tend to originate as

A)minor perturbations of the jet stream
B)thunderstorms in West Africa
C)major pressure lows over the equatorial ocean
D)typhoons off the Iberian Peninsula

Question 19

The current flowing parallel to and just offshore of a beach is called

A)littoral current
B)longshore current
C)beach current
D)down current

Question 20

What aspect of tropical cyclones tends to cause the greatest death and destruction?

A)the intensely low atmospheric pressure in the storm's eye
B)the intense wind
C)flooding from rain, waves, and storm surge
D)lightning from thunderstorms spawned by the cyclone

Question 21

Soft stabilization of coastal erosion utilizes seawalls constructed of soft, cushioned materials versus hard materials such as steel.

Question 22

Littoral transport is driven by the oblique approach of waves to the shoreline.

Question 23

The E-10 zone in the coastal erosion hazard mapping scheme is the zone in which erosion is predicted to happen over the next ________ time period.

Question 24

A rise in sea level is likely to cause greater coastal erosion.

Question 25

Hurricanes tend to strengthen over warm ocean water.

Question 26

The goal of groin installation is to trap sand.

Question 27

The ________ is the time it takes for successive wave crests to pass a point.

Question 28

A(n) ________ is a lethal rise in the sea surface level caused by a hurricane.

Question 29

________ breakers are wave types that occur on steeply sloping beach faces.

Question 30

Hurricane waves at sea are the greatest hazard presented by hurricanes.

Question 31

Seacliff erosion tends to occur at a greater rate during the summer.

Question 32

________ is the combination of beach drift and longshore drift.

Question 33

A(n) ________ is a narrow flow of water away from the beach and into deep water.

Question 34

Lake level variations are the strongest control on erosion along the Great Lakes shorelines.

Question 35

A pair of ________ typically protects the channel of a river entering the sea.

Question 36

Assateague Island, Maryland, has avoided coastal erosion because it is largely undeveloped.

Question 37

________ is a "soft" solution to coastal erosion that tends to imitate natural processes.

Question 38

Hurricanes develop from areas of low atmospheric pressure called tropical ________.

Question 39

Tropical cyclones are called ________ in the western Pacific Ocean.

Question 40

Wave normals ________ on a rocky headland.

Question 41

The balance of sediment input and output along a stretch of coastline is called the ________.

Question 42

As waves are sorted as distance increases from the source area, they develop a regular frequency and become ________.