Deck 12: Waves, Currents, and Coastlines

Question 1

On the west coast of Canada,sudden changes in the shoreline are likely caused by

A) hurricanes.
B) earthquakes.
C) glaciation.
D) coastal erosion.
E) rising sea level.

Answer 1

B

Question 2

At what depth do waves begin to slow down and "feel bottom"?

A) at depth equal to twice the wavelength
B) at depth equal to one wavelength
C) at depth equal to ½ wavelength
D) at depth equal to ¼ wavelength
E) Never. Waves don't slow down.

Answer 2

C

Question 3

Steep rock shorelines that experience only limited erosion would be most common

A) along a passive margin.
B) along the Great Lakes.
C) along the eastern coastline of United States.
D) along the British Columbia coastline.
E) along shorelines with wide continental margins.

Answer 3

D

Question 4

Bluff erosion in the Great Lakes is most severe

A) during storms.
B) during the winter.
C) during the summer.
D) when lake levels are high because of above-normal precipitation.
E) when lake levels are low because of below-normal precipitation.

Question 5

At a regional level,shorelines on a tectonically passive margin commonly have

A) sea cliffs.
B) rocky shorelines.
C) narrow continental shelves.
D) extensive sandy beaches.
E) little coastal erosion.

Question 6

If you were watching waves from the shore and started counting the seconds between one crest to the next,what would you be measuring?

A) Wave height
B) Wave length
C) Wave period
D) Wave energy
E) Wave speed

Question 7

Why are East Coast beaches in North America wider and sandier in general than West Coast beaches?

A) The East Coast is nearer to a convergent boundary.
B) The East Coast is nearer to a subduction zone.
C) The East Coast is far from a convergent plate boundary.
D) The East Coast is nearer to a deeper ocean.
E) The East Coast has more rocks to erode.

Question 8

Which of the following is NOT a coastal hazard?

A) sea-level rise
B) flooding
C) coastal erosion
D) tsunami
E) storm surges

Question 9

Wave erosion is limited in much of the Arctic because

A) there are no beaches.
B) the region is tectonically active.
C) sea level is consistently rising.
D) the whole coastline is rocky.
E) fetch is limited by sea ice.

Question 10

Included in the definition of littoral drift is

A) beach drift and longshore drift.
B) trombolo and spit.
C) ebb tide and beach drift.
D) beach face, longshore drift.
E) ebb tide and longshore drift.

Question 11

Plunging breakers are produced

A) when waves converge at a headland.
B) when waves diverge along a shoreline.
C) by a tidal bore.
D) when a wave encounters a steep beach.
E) when a wave encounters a gently sloping beach.

Question 12

The portion of a beach that experiences the repeated up-rush and backwash of waves is called the

A) swash zone.
B) surf zone.
C) breaker zone.
D) sea cliff.
E) longshore bar.

Question 13

Which of the following parameters least influences the movement of a wave or wave crest?

A) wave height
B) wavelength
C) wave period
D) water depth
E) water temperature

Question 14

Long-term changes in the sediment budget of beaches can be caused by

A) climate change.
B) hurricanes.
C) nor'easters.
D) wave erosion.
E) winter storms.

Question 15

Barrier islands require the following condition for their formation.

A) rip currents
B) littoral drift
C) eustasy
D) isostasy
E) wave refraction

Question 16

Which of the following is the best way to measure the wave height of a set of waves at the beach?

A) Hold a meterstick in the water and measure how high the wave goes on the stick.
B) Count the number of waves that pass by in a minute.
C) Using a stopwatch, time the waves as the crests move by.
D) Take a picture of the waves with a camera and measure the distance between the crests with a ruler.
E) Using a scale, measure the pressure of the largest wave.

Question 17

The level of the sea at the shoreline cannot be directly influenced by

A) changes in wind speed.
B) changes in atmospheric pressure.
C) changes in air temperature.
D) tidal forces.
E) changes in sea temperature.

Question 18

Wind-generated waves can get bigger in the Pacific Ocean than they can in Lake Superior.Why?

A) because the Pacific Ocean is salt water and Lake Superior is fresh water
B) because the wind blows faster over the Pacific Ocean than over Lake Superior
C) because the fetch is greater in the Pacific Ocean than in Lake Superior
D) because the Pacific Ocean is deeper than Lake Superior
E) because the wind always blows in the same direction over the Pacific Ocean

Question 19

If you placed a small boat in waves in the open ocean (not near the shoreline)what would the motion of the boat be?

A) up and down slowly moving towards shoreline
B) up and down slowly moving out to sea
C) circular pattern staying mostly in the same place
D) circular pattern slowly moving towards the shoreline
E) circular pattern slowly moving out to sea

Question 20

Wave orbits tend to decrease in size as the depth of the water decreases.Orbital motion essentially stops at a depth of

A) 2 times the wavelength.
B) 0.5 times the wavelength.
C) At distance equivalent of the wavelength.
D) 1 meter.
E) 7 meters.

Question 21

Of the following choices,where would you be most likely to encounter rogue waves?

A) off the southern coast of South Africa
B) in the Gulf of St. Lawrence
C) in the Pacific Ocean off San Francisco
D) in the Arctic Ocean
E) at the equator in the Atlantic Ocean

Question 22

Rising sea level and the disappearance of islands off the coast of Nova Scotia can most likely be attributed to

A) more nor'easters.
B) stronger hurricanes.
C) bigger fetch.
D) human activity.
E) glacio-isostatic subsidence.

Question 23

If you went swimming in the ocean and you swam out farther than the breakers,then floated,which of the following best describes the motion you undergo as incoming waves pass you by?

A) You move up and down.
B) You move toward and away from the beach.
C) You move back and forth parallel to the shore.
D) You move in an orbital pattern.
E) You move directly toward the beach.

Question 24

Beach nourishment

A) is a controversial coastal erosion solution.
B) is a rarely used solution to coastal erosion.
C) is a relatively inexpensive coastal erosion solution.
D) is a permanent solution to coastal erosion.
E) has always been an effective means of combating coastal erosion.

Question 25

Which of the following is a "soft" engineering solution to coastal erosion?

A) Raise houses on pilings, so erosion problems do not threaten the entire structure.
B) Build jetties to protect the entrances to harbors.
C) Build breakwaters to provide calm waters for boats to anchor.
D) Add sand to the beach to compensate for longshore drift loss.
E) Use riprap to build barriers to erosion.

Question 26

Where would you find a bluff?

A) along the coast of Florida
B) along the west coast of Vancouver Island
C) along the outer banks of North Carolina
D) along the shore of Lake Ontario
E) along the shore of Long Island, New York

Question 27

On the west coast of North America,most sea-cliff erosion occurs during which season?

A) late spring
B) summer
C) early fall
D) late fall
E) winter

Question 28

Which of the following is a hard engineering solution to coastal erosion?

A) removal of structures on the beach
B) installation of beach groins
C) beach nourishment
D) building of vegetated dunes
E) not building in hazardous areas

Question 29

A study of sea-cliff erosion in California indicated that people living inland from the coast

A) were aware that the coast is eroding but did not consider it a hazard.
B) were generally well informed and saw erosion as a threat.
C) were aware that the coast is eroding but knew little of its severity.
D) were unaware that the coast was eroding.
E) wanted to be relocated further inland.

Question 30

A linear structure placed perpendicular to the shore and designed to trap sand carried by longshore drift is called a

A) seawall.
B) groin.
C) breakwater.
D) jetty.
E) riprap.

Question 31

Which of the following is a long-term solution to coastal erosion hazards?

A) stabilize the shoreline by building groins
B) "harden" the shoreline by building seawalls
C) "nourish" the beach by adding sand to it
D) stabilize channels by building jetties
E) relocate buildings that are at risk

Question 32

In Canada,there are fewer fatalities per capita associated with rip currents than there are in the United States.Why?

A) Rip currents are less common in Canada.
B) Canadian beaches are too short to form rip currents.
C) Rip currents only form on barrier islands, which are more common in the United States.
D) The water off Canadian shores is often too cold for most swimmers.
E) Education about rip currents is more prevalent in Canada.

Question 33

Under which of the following conditions will longshore drift occur?

A) wave crests approaching parallel to the shoreline
B) wave crests approaching a rocky headland
C) wave crests approaching at an angle to the shoreline
D) wave crests higher than average
E) wave crests lower than average

Question 34

Which of the following characteristics of waves remains constant as waves approach the shoreline?

A) wavelength
B) wave height
C) wave frequency
D) wave energy
E) wave period

Question 35

If you went down to the shoreline and wanted to measure the wave period of incoming waves,what equipment would you need?

A) a measuring tape
B) a meter stick
C) a stopwatch
D) a measuring tape and a stopwatch
E) a meter stick and a stopwatch

Question 36

If you were a surfer,why might you be interested in reports of distant storms?

A) Wind from distant storms could arrive in your area several days later.
B) Rainy weather from distant storms might arrive in your area later.
C) Swell from distant storms might arrive in your area later.
D) Rogue waves from distant storms might arrive in your area later.
E) Warm water from distant storms might arrive in your are later.

Question 37

Which of the following statements is TRUE about waves?

A) Waves break because they rise too high in shallow water.
B) Waves diminish greatly in size as they move across the ocean.
C) Waves are mostly random and cannot be predicted.
D) Wavelength increases when the wave approaches the shoreline.
E) Waves speed up when they approach the coastline.

Question 38

Spilling breakers are common on which type of shoreline?

A) base of cliffs with boulders
B) steep cobble beach
C) steep gravel beach
D) moderate slope gravel beach
E) gentle slope sandy beach

Question 39

What limits coastal erosion on the Arctic coast of Canada?

A) cold temperatures
B) low wind speeds
C) rocky shorelines
D) melting permafrost
E) sea ice

Question 40

How can damming rivers upstream contribute to erosion problems at the shoreline?

A) Dams prevent natural flood events that would erode and reshape beaches.
B) Dams trap sediment that would otherwise supply sand to beaches.
C) Dams reduce water flow year round, allowing tidal currents to erode farther inland.
D) Dam construction weakens sea cliffs.
E) Artificial floods of water released from dams causes extreme erosion.

Question 41

Which type of wave would you expect to see on a barrier island on the East Coast of Canada?

A) plunging breaker
B) spilling breaker
C) tidal wave
D) tsunami
E) divergent breaker

Question 42

How would you spot a rip-current from the shore?

A) Look for an area where waves are moving towards the shore.
B) Look for an area where longshore are moving quickly parallel to the shore.
C) Look for an area of calm surrounded by breaking waves.
D) Look for an area of intense breaking waves.
E) Rip currents are not visible from the shore.

Question 43

Longshore drift and beach drift are both processes associated with littoral transport.

Question 44

Which of the following hard stabilizations is built parallel to shore and is intended to protect homes,cliffs,or bluffs?

A) jetties
B) breakwaters
C) seawalls
D) beach nourishment
E) groins

Question 45

Rogue waves only appear in the open ocean during stormy conditions.

Question 46

A barrier island is a landform produced by littoral drift.

Question 47

Most steep,high-energy beaches are formed of sand.

Question 48

Swell refers to waves generated by storms far out at sea.

Question 49

What is the difference between eustatic and relative sea level?

A) Eustatic refers to the global sea level; relative refers to local sea level near land.
B) Eustatic refers to global sea level; relative refers to sea levels with respect to mid-ocean ridges.
C) Eustatic refers to sea levels that don't change; relative refers to local sea level.
D) Eustatic refers to sea levels that are advantageous for shipping; relative sea level refers to high and low tides.
E) There is no difference between them.

Question 50

Sea level has been rising globally over the past century due to expansion of upper ocean waters.

Question 51

Coasts with long sandy beaches are more abundant in tectonically active areas.

Question 52

What could cause a large change in eustatic sea level?

A) tides
B) heavy storms
C) drought
D) global warming
E) earthquakes

Question 53

Spilling breakers are commonly associated with steep beaches.

Question 54

Swell is generated by storms far out at sea.

Question 55

Longshore drift is the transport of sediment by currents that flow parallel to the shore.

Question 56

At a depth equal to their wavelength waves begin to feel the bottom.

Question 57

Divergence of wave normals usually occurs away from a headland.

Question 58

Which type of wave would you expect to see on a barrier island on the West Coast of Canada?

A) plunging breaker
B) spilling breaker
C) tidal wave
D) tsunami
E) divergent breaker

Question 59

Much of the sea-level rise in Atlantic Canada can be attributed to the melting of the Laurentide ice sheet.For what reason is this true?

A) The glacier is still melting and adding water to the oceans.
B) Water released from the glacier is thermally expanding.
C) Atlantic Canada is undergoing subsidence due to the positioning of the ice sheet.
D) The glacier changed global weather patterns.
E) The local continental shelf is uplifting due to the melting of the glacier.

Question 60

Which of the following hard stabilizations is built in an effort to protect boats in the harbor?

A) jetties
B) breakwaters
C) seawalls
D) beach nourishment
E) groins

Question 61

The long-term effect of wave refraction is to straighten the shoreline (unless other non-wave processes intervene).

Question 62

Storms are commonly the most important influence on the long-term sediment budget of beaches.

Question 63

Stabilization of beaches with engineered structures protects beaches.

Question 64

Waves get sorted into groups far out in the ocean and when they hit the shore they are of similar sizes.

Question 65

Longshore drift occurs only on ocean beaches,not on shorelines of lakes.

Question 66

Coastal erosion is a natural process.

Question 67

The swash zone is located seaward of the berm.

Question 68

Rip currents can be strong enough to pull people under the water.

Question 69

A tombolo is more likely to form near a wide sandy beach than a rocky coastline.

Question 70

Tidal bores have very steep fronts,up to several metres high.

Question 71

Most of the sand moves parallel to the shoreline due to longshore currents.

Question 72

Colder water in Canada results in fewer fatalities from rip currents than in the United States.

Question 73

Wave erosion is limited in the arctic due to a reduction in fetch caused by sea ice.

Question 74

Relative sea level fluctuates constantly throughout the day.

Question 75

Jetties trap sediment and therefore always decrease beach erosion.

Question 76

An increase in ocean volume caused by thermal expansion is an example of eustatic sea-level change.

Question 77

The most effective hard stabilization is beach replenishment.

Question 78

A rogue wave is a wave that pulls a person out into the ocean rather than towards the shore.

Question 79

Rising sea level will increase coastal erosion hazards.

Question 80

Isostasy refers to global changes in sea level that can be associated with a change in shape of the ocean.basins