Deck 11: Coasts

Question 1

Which of the following best describes the foreshore of a beach?

A)It is the active zone of the beach that is washed by waves during the daily rise and fall of the tides.
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 area bellow the low-tide mark, where wave action, turbulent backwash, and longshore currents excavate a trough.

Answer 1

A

Question 2

A long, shallow body of seawater isolated from the ocean, that lies between the shoreline and a barrier island is called a ____.

A)bay
B)sand spit
C)lagoon
D)tombolo

Answer 2

C

Question 3

Most often, sediments found on the beaches of depositional coasts are supplied by ____.

A)erosion of local coastal cliffs
B)erosion of basement rock along the shoreline
C)glacial processes
D)rivers or ocean currents

Answer 3

D

Question 4

Steep sea cliffs on erosional coasts are usually caused by ____.

A)exposure of these features due to a drop in sea level
B)deposition of large amounts of sediment by waves
C)glacial erosion
D)the collapse of undercut notches of exposed bedrock

Question 5

A long-term effect of wave refraction is ____.

A)to smooth and straighten a shoreline
B)to add sediment to headlands that extend outward from the shore
C)to erode and deepen bays
D)to remove sand from the beach

Question 6

Deep, narrow bays that are often formed by tectonic forces and later modified by glaciers are called ____.

A)lagoons
B)drowned river mouths
C)fjords
D)bay mouth bars

Question 7

Which of the following is true for depositional coasts?

A)They have never been changed by wave action since sea level stabilized.
B)They never support beaches.
C)Exposed bedrock is more common than loose sediment on depositional coasts.
D)Beaches are a common feature on depositional coasts.

Question 8

Beaches with very fine-grained sediments tend to be ____.

A)relatively steep
B)relatively flat
C)most common along erosional coastlines
D)in areas where the coast is rapidly rising or sinking

Question 9

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 10

The highest point on a summer beach profile is the ____.

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

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

The movement of sediment (usually sand)along the coast, driven by wave action, is referred to as ____.

A)wave reflection
B)foreshore current
C)longshore drift
D)estuarine drift

Question 13

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 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)active environments that are subject to rearrangement by waves and tides, by gradual changes in sea level, by biological processes, and by tectonic activity
D)that part of the marine environment most resistant to change

Question 15

It is believed that over the past two 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

Question 16

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)sediment deposition connects a barrier island to the mainland

Question 17

A vertical wall of variable height that is often carved into a beach by wave action at high tide is called a ____.

A)berm
B)beach scarp
C)foreshore
D)backshore

Question 18

A(n)____ is a bridge of sediment that connects a sea island to the mainland.

A)inlet
B)tombolo
C)sand spit
D)bay mouth bar

Question 19

The Mississippi River delta is an example of a ____.

A)tide-dominated delta
B)river-dominated delta
C)wave-dominated delta
D)mixed delta

Question 20

On high energy shores ____ does most of the erosional work.

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

Question 21

Marine erosion is usually most rapid on low-energy coasts.

Question 22

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)salt wedge estuary
C)partially mixed estuary
D)reverse estuary

Question 23

Short extensions of rock or other material that are placed at right angles to longshore drift to stop the longshore transport of sediments are called ____.

A)berms
B)seawalls
C)groins
D)dolos

Question 24

Which statement is true concerning estuaries?

A)Organisms cannot survive in estuaries.
B)Estuaries are very vulnerable to pollution.
C)The salinity in estuaries is stable, with very little fluctuation.
D)An estuary is a type of delta.

Question 25

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

Question 26

Breakwaters alter beaches by ____.

A)diverting sand away from boat anchorages that the breakwater was built to provide
B)interrupting the progress of waves to the beach and weakening the longshore current
C)allowing freshwater to flow readily into the ocean
D)filling in bays or inlets

Question 27

Which statement is true regarding the Florida Keys?

A)They were formed during an ice age period.
B)They are an example of an erosional coast.
C)They are an example of a coast formed by biological activity.
D)They are completely below sea level.

Question 28

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

Question 29

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

Question 30

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 31

An example of a partially mixed estuary is ____.

A)Milford Sound
B)Chesapeake Bay
C)the mouth of the Columbia River
D)the mouth of the Mississippi River

Question 32

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

Question 33

Human activities that can significantly contribute to shoreline erosion include ____.

A)building sand dunes near the backshore to protect property
B)importing sand to beaches from offshore
C)placement of seawalls along the shoreline
D)excess fishing and boating activities

Question 34

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

Question 35

Which statement is true with regard to breakwaters?

A)Beach sand is eroded on the downstream side of the breakwater.
B)Breakwaters interrupt the progress of waves to the beach.
C)Breakwaters strengthen longshore currents.
D)Breakwaters are often built to provide nesting habitat for shore birds.

Question 36

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

Question 37

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

Question 38

The Ganges-Brahmaputra delta is an example of a wave-dominated delta.

Question 39

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

Question 40

The steep cliffs and rugged headlands common along much of the Pacific Coast of the United States are primarily the result of ____.

A)recent tectonic activity
B)marine deposition
C)river deposition
D)glacial erosion

Question 41

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

Question 42

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

Question 43

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

Question 44

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

Question 45

What is an estuary and how are they unique ecosystems?