Introduction to Environmental Geology, 5e (Keller)
Chapter 11 Coastal Processes
11.1 Multiple-Choice Questions
1) 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
2) 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.
3) 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.
4) Which of the following does not influence wave size?
A) wind velocity
B) wind duration
C) wind fetch
D) wind temperature
5) 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
6) 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.
7) 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
8) 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.
9) 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.
10) 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.
11) 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.
12) 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
13) 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
14) 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
15) 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
1) Coastal landscapes are capable of rapid change because continental and oceanic processes
converge there.
2) The Cape Hatteras lighthouse was moved inland because a major storm damaged it in 1994.
3) As waves enter the coastal zone, wavelengths shorten and wave heights increase.
4) Ocean swell consists of a chaotic distribution of wave heights and lengths.
5) Refraction occurs because waves speed up as they reach the shallower water near the beach.
6) Littoral transport is driven by the oblique approach of waves to the shoreline.
7) A rise in sea level is likely to cause greater coastal erosion.
8) Seacliff erosion tends to occur at a greater rate during the summer.
9) The goal of groin installation is to trap sand.
10) Assateague Island, Maryland, has avoided coastal erosion because it is largely undeveloped.
11) Hurricanes tend to strengthen over warm ocean water.
12) Soft stabilization of coastal erosion utilizes seawalls constructed of soft, cushioned materials
versus hard materials such as steel.
13) Hurricane waves at sea are the greatest hazard presented by hurricanes.
14) Lake level variations are the strongest control on erosion along the Great Lakes shorelines.
11.3 Short Answer Questions
1) The ________ is the time it takes for successive wave crests to pass a point.
2) Wave normals ________ on a rocky headland.
3) ________ is the combination of beach drift and longshore drift.
4) ________ breakers are wave types that occur on steeply sloping beach faces.
5) A(n) ________ is a narrow flow of water away from the beach and into deep water.
6) A pair of ________ typically protects the channel of a river entering the sea.
7) Tropical cyclones are called ________ in the western Pacific Ocean.
8) A(n) ________ is a lethal rise in the sea surface level caused by a hurricane.
9) 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.
10) ________ is a “soft” solution to coastal erosion that tends to imitate natural processes.
8
11) Hurricanes develop from areas of low atmospheric pressure called tropical ________.
12) As waves are sorted as distance increases from the source area, they develop a regular
frequency and become ________.
13) The balance of sediment input and output along a stretch of coastline is called the ________.