Deck 8: Coasts

Question 1

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

Answer 1

C

Question 2

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

Answer 2

C

Question 3

The place where the ocean meets land is usually called the .

A) beach
B) shore
C) bay
D) coast

Answer 3

B

Question 4

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) part of the marine environment most resistant to change

Question 5

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 6

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 7

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 8

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 9

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

Question 10

Which statement describes eustatic changes to local environments?

A) Tectonic motions and isostatic adjustment can change the height and shape of a coast.
B) Global warming can cause seawater to expand and occupy move volume.
C) High rates of seafloor spreading are associated with expansion in volume of oceanic ridges.
D) Global glaciation causes ocean water to freeze in land-based glaciers.

Question 11

Periodic uplift or wave-cut platforms result in .

A) river valleys known as fjords
B) protruding shorelines termed headlands
C) stair-step formations called marine terraces
D) crescent-shaped shoreline called bays

Question 12

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 13

Which of the following factors would cause sea level to fall?

A) Periods of global glaciation trap water in land-based glaciers.
B) Global warming causes seawater to expand and occupy more volume.
C) Expansion of oceanic ridges displaces seawater
D) Sediment shed by the continents during periods of rapid erosion displaces seawater.

Question 14

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 15

The highest point on a summer beach profile is the .

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

Question 16

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 below the low-tide mark, where wave action, turbulent backwash,  and longshore currents excavate a trough.

Question 17

Which  statement describes how volcanoes can shape the coastline?

A) Lavas force waves cut through cliffs to form sea caves.
B) Lava flowing seaward from an eruption forms fresh coast exposed to erosion.
C) Volcanic eruptions fall on the ocean floor and form sea stacks.
D) Emptying of volcano chambers resulting in drowned river valleys.

Question 18

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 19

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 20

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 21

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 22

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 23

Coral reefs most commonly form .

A) in the tropics
B) along the equator
C) near the poles
D) near river runoffs

Question 24

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 25

The Atlantic coast is also referred to as a(n) .

A) margin that continually changes from being a passive margin to an active margin and then back to passive margin
B) active margin
C) margin that gradually transitions from a passive to an active margin
D) passive margin

Question 26

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 27

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 28

Deltas are most common .

A) on low-energy shores of enclosed seas
B) along convergent zones of the western margins of North America
C) near the west coast of South America
D) along the passive margin of the Atlantic coast of North America

Question 29

Which statement is true regarding the coast of southwestern Florida?

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 30

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

Question 31

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 32

A sand spit forms when .

A) a long-shore current speeds up when approaching a headland
B) a long-shore current slows as it clears a headland and approaches a quiet bay
C) a turbidity current flows near a coast
D) sediment deposition connects a barrier island to the mainland

Question 33

Subsidence in the Gulf coast is mainly due to .

A) tectonic activity
B) emptying of a volcanic chamber
C) coastal erosion
D) sediment compaction

Question 34

Which feature is typically found along Atlantic-type passive margins?

A) subsiding coast
B) jagged rocky headland
C) marine terrace
D) plate boundary

Question 35

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 36

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 37

What type of delta forms when freshwater discharge delivers sediments into long islands parallel to the river flow and perpendicular to the trend of the coast?

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

Question 38

The Pacific coast is commonly called a(n) .

A) active margin
B) passive margin
C) margin that gradually transitions from a passive to an active margin
D) margin that continually changes from being a passive margin to an active margin and then back to passive margin

Question 39

The greatest of all reefs is the .

A) Florida Keys
B) Red Sea Coral Reef
C) Australian Great Barrier Reef
D) Belize Barrier Reef

Question 40

Which feature is typically found along Pacific-type active margins?

A) thick sediment deposit
B) flooded valley
C) barrier island
D) plate boundary

Question 41

The beach scarp, a vertical wall of variable height, marks the end of the seaward profile of a beach.

Question 42

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

Question 43

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

Question 44

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

Question 45

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 46

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 47

Estuaries are typically classified into four types depending on their origins.

Question 48

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

Question 49

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 50

Sea caves formed by wave action may eventually become sea arches and in time collapse to become sea stacks.

Question 51

Three factors determine the characteristics of estuaries: the shape of the estuary, the volume of river flows at the head of the estuary, and the range of tides at the estuary's mouth.

Question 52

Australia's Great Barrier Reef is an example of how living organisms such as corals can influence coastlines.

Question 53

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

Question 54

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 55

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

Question 56

The rate of subsidence of the Gulf coast is less than that of nearly all of the Atlantic or Pacific coasts.

Question 57

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

Question 58

The Gulf coast experiences a tidal range and a average wave size than either the Pacific or Atlantic coasts.

A) smaller; smaller
B) smaller, larger
C) larger; smaller
D) larger; larger

Question 59

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

Question 60

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

Question 61

What processes give the Gulf coast its distinctive characteristic that is different from the Atlantic and Pacific coasts of the United States?

Question 62

List the different types of deltas and briefly describe how the different types are classified.

Question 63

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

Question 64

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

Question 65

How do coasts receive new sand? Describe the concept of a coastal cell.

Question 66

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

Question 67

Compare and contrast the characteristics of the Pacific coast to the characteristics of the Atlantic coast of the United States.

Question 68

How do volcanoes and earthquakes modify the shape of coastlines? Give an example of each.

Question 69

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

Question 70

What is an estuary and how are they unique ecosystems?