Deck 11: Coasts

Question 1

It is believed that over the past 2 million years, world sea level has:

A) changed, but not significantly.
B) varied from about 6 meters above to about 125 meters below present position.
C) varied from about 125 meters above to about 6 meters below present position.
D) not changed.

Answer 1

B

Question 2

Solution, abrasion, and hydraulic action are factors involved in:

A) wave deposition.
B) moving longshore currents.
C) causing wave refraction.
D) wave erosion.

Answer 2

D

Question 3

If a beach is wide, gently sloping with fine sands, we would expect to see:

A) very heavy wave action.
B) a beach facing into Arctic storms.
C) generally small waves winter and summer.
D) high-energy waves all year around.

Answer 3

C

Question 4

An estuary which forms where a rapidly flowing large river enters the ocean in an area where tidal range is low to moderate is called:

A) a well-mixed estuary.
B) a salt wedge estuary.
C) a partially mixed estuary.
D) a reverse estuary.

Question 5

The highest point on a summer beach profile is:

A) the berm.
B) the backshore.
C) the foreshore.
D) the low-tide terrace.

Question 6

A summer beach is characteristically:

A) a rocky platform.
B) steep and narrow.
C) covered with boulders and cobbles.
D) broad and covered with sand.

Question 7

Steep, narrow, rocky beaches are usually found in areas of:

A) summer beach conditions.
B) wave deposition.
C) high wave energy.
D) small inlets and bays.

Question 8

The steep cliffs and rugged coast of much of the West Coast of the United States are primarily the result of:

A) faulting and earth movement.
B) marine deposition.
C) river deposition.
D) glacial erosion.

Question 9

Which of the following is FALSE for depositional coasts?

A) They have been changed by wave action since sea level stabilized.
B) They never support beaches.
C) They tend to be older than primary coasts.
D) They tend be straighter than primary coasts.

Question 10

The single most influential agent changing the shore and coast is:

A) wave action.
B) the tidal range.
C) alternate freezing and thawing of coastal cliffs.
D) prevailing winds.

Question 11

The origin of sea cliffs, sea stacks, sea caves, blowholes, and arches is related to:

A) longshore currents.
B) high tides.
C) human activities.
D) erosion by waves.

Question 12

A problem facing many beaches along the U.S. east and west coasts is:

A) excess sand being deposited around seaside installations.
B) the rapid growth of deltas at the mouths of rivers.
C) the development of barrier beaches across harbors.
D) the loss of sand and the erosion of beaches.

Question 13

The energy that drives the longshore currents is derived from:

A) hurricanes and cyclones.
B) major surface currents, such as the Gulf Stream.
C) monthly high tides.
D) wind waves approaching the beach front at an angle.

Question 14

The present shorelines of the world are considered to be:

A) geologically stable zones separating land and sea.
B) features of great geological antiquity.
C) a dynamic environment affected by both long-term and short-term cycles.
D) that part of the marine environment most resistant to change.

Question 15

The downcoast transport mechanism for beach sand along much of the Pacific coast is called:

A) the longshore current, a current that moves sand north-to-south along the coast, parallel to shore, at a great distance away from land.
B) the longshore current, a current that moves sand south-to-north along the coast, parallel to shore, at a great distance away from land.
C) the longshore current, a current that moves sand north-to-south along the coast, parallel to shore, close to shore.
D) the longshore current, a current that moves sand south-to-north along the coast, parallel to shore, close to shore.

Question 16

Oceanographers usually classify coasts by:

A) the type of sand found on the beach.
B) the physical processes shaping the coasts.
C) the direction the coast faces.
D) the latitude in which the coast resides.

Question 17

Human activities that have contributed to shoreline erosion include:

A) seasonal traffic at beaches during the summer months
B) depositional processes
C) placement of seawalls along the shoreline
D) excess fishing and boating activities

Question 18

Most of the minerals found in the sand of continental beaches are supplied by:

A) erosion of local coastal cliffs.
B) currents from the deep ocean floor.
C) glacial processes.
D) rivers and streams.

Question 19

The large waves of late summer modify the shape of sandy beaches. Huge "bites" of beach are removed from the exposed beach and end up in offshore sand bars. These "bites" are most evident in the form of a very large and high:

A) berm.
B) shore face, or beach scarp.
C) foreshore.
D) backshore.

Question 20

A long-term effect of wave refraction is:

A) to smooth and straighten a coast.
B) to build out points of land.
C) to erode and deepen bays.
D) to remove sand from the beach.

Question 21

One mechanism by which sediments are transported in the surf zone is via longshore currents.

Question 22

Eustatic changes are variations in sea level that can be measured all over the world ocean.

Question 23

A longshore bar is a vertical wall of sand delineating the low-tide mark.

Question 24

Deltas form at the mouths of sediment-laden rivers and where continental shelves are broad.

Question 25

Barrier islands were once part of the mainland when sea levels were lower.

Question 26

A sand spit forms when:

A) a long-shore current speeds up.
B) a long-shore current slows.
C) a turbidity currents flows near a coast.
D) a gyre approaches coasts.

Question 27

Estuaries are categorized by:

A) location or latitude.
B) circulation patterns.
C) the ratio of fresh water to salt water.
D) sediment origins and age.

Question 28

Depositional coasts are growing because of sediment accumulation or the action of living organisms.

Question 29

Which of the following statements is FALSE regarding the Florida Keys?

A) They were formed during a time between glaciations.
B) They are an example of a coral reef coast.
C) They are an example of a coast formed by biological activity.
D) They are relatively low and extend below sea level.

Question 30

Over time, the amount of water in the world ocean has remained constant.

Question 31

Both land erosion and sea-level changes can shape a coastline.

Question 32

The Florida Keys is an example of how living organisms such as corals can influence coastlines.

Question 33

Which of the following statements is FALSE concerning breakwaters?

A) Sand accumulates directly in front of the breakwater.
B) Breakwaters interrupt the progress of waves to the beach.
C) Breakwaters weaken longshore currents.
D) Breakwaters are often built to protect small-boat anchorages.

Question 34

The variation in sea level that can be measured over the world ocean is called:

A) erosional change.
B) tectonic change.
C) dynamic change.
D) eustatic change.

Question 35

Which of the following statements is FALSE concerning estuaries?

A) Many organisms live in estuaries.
B) Estuaries are very vulnerable to pollution.
C) The salinity in estuaries varies because of mixing.
D) An estuary is a type of delta.

Question 36

An example of a partially mixed estuary is:

A) Milford Sound.
B) Chesapeake Bay.
C) Sydney Harbour.
D) San Francisco Bay.

Question 37

A(n) ____ is a bridge of sediment that connects sea islands.

A) inlet.
B) tombolo.
C) estuary.
D) delta.

Question 38

The function of a breakwater is to:

A) divert sand away from a swimming area.
B) interrupt the progress of waves to the beach.
C) allow freshwater to flow readily into the ocean.
D) fill in a bay or an inlet.

Question 39

Which of the following bests describes the berm of a beach?

A) It is the accumulation of sediment that runs parallel to shore.
B) It is highest part of a beach.
C) It is the part of the beach that has windblown dunes and grasses.
D) It is the accumulation of sediment due to turbidity currents.

Question 40

Marine erosion is most rapid on low-energy coasts.

Question 41

What is a beach? Define the term and describe features and processes that may bound the limits of a beach.

Question 42

Define the term coast and describe the factors that shape coastlines.

Question 43

What is an erosional coast and how are they different from other types of coasts?

Question 44

How have human activities influenced coastal processes? Give a specific example.

Question 45

What is an estuary and how are they unique ecosystems?