Deck 19: Shorelines

Question 1

With respect to constructing seashore buildings or foreshore engineering works, the best advice should be: ________.

A)Builder beware; if you treat this as an unchanging setting, you will put yourself and your resources in conflict with awesome forces of nature.
B)Don't build resorts or houses but seawalls and port facilities can be made strong enough.
C)Fight for publicly funded maintenance and insurance programs to protect your private investments.
D)Don't worry mon, be happy.

Answer 1

A

Question 2

The ________ is the line that marks the contact between land and sea.

A)Beach
B)Shoreline
C)Interface
D)Foreshore

Answer 2

B

Question 3

Under which conditions will a wave be considered a deep-water wave?

A)Wavelength > 1/2 water depth
B)Wave height > water depth
C)Wavelength > 1/2 wave height
D)Water depth > 1/2 wavelength

Answer 3

D

Question 4

________ is not a dynamic characteristic of a wave.

A)Fetch
B)Wavelength
C)Period
D)Velocity or speed

Question 5

When does a deep-water wave change to a shallow water wave?

A)only when the wave period is greater than one-half the water depth
B)only when the wavelength is about twice the water depth
C)only when the wave period is greater than twice the water depth
D)only when the wavelength is about one-half the water depth

Question 6

How, if at all, did sea level change at the end of the Pleistocene Epoch?

A)It has fallen about 10 centimetres per century due to human use of water for irrigation.
B)It has remained about the same.
C)It rose about 100 metres during the recession of the last ice sheets.
D)It rose and drowned the ancient city of Atlantis.

Question 7

Abrasion will be greatest in which part of the beach environment?

A)Offshore Zone
B)Surf Zone
C)Backshore
D)Berms

Question 8

How can crashing, collapsing, storm waves generate explosive forces and stresses on rocky outcrops and manmade structures?

A)Oscillating, refractive waves shake the hard materials into small fragments.
B)The weight, momentum, and pressure of storm waves compresses air into cracks, shattering rock.
C)Backwash breaks out blocks of rock or concrete and carries them to deeper water.
D)Storm waves hurl big rocks up into the suspended load, hammering the shore.

Question 9

________ refers to the movements of sand and water on a beach face due to a breaking wave.

A)Slash and slosh
B)Backwash and swash
C)Pish and tosh
D)Wash and backslosh

Question 10

If the distance from one wave crest to the next is 10 metres, what will the depth to the wave base be?

A)2 metres
B)5 metres
C)11 metres
D)20 metres

Question 11

________ directly generates the major surface currents in the world's oceans.

A)Gravity of the Sun and Moon
B)Seafloor spreading
C)Longshore drift
D)Wind

Question 12

All waves represent ________.

A)an interference pattern of crests caused by high tide and troughs caused by low tide
B)energy travel through water, usually caused by wind stress
C)rambunctious gods playing at the edge of the world
D)the inertial sloshing of ocean waters caused by Earth's rotation

Question 13

What is the minimum wind velocity needed to create a wave?

A)3 km/hr
B)5 km/hr
C)8 km/hr
D)10 km/hr

Question 14

How much pressure can be exerted by those "perfect waves" that characterize the North Atlantic winter storms?

A)1 kg/m²
B)100 kg/m²
C)10,000 kg/m²
D)1,000,000 kg/m²

Question 15

Fetch refers to ________.

A)the beachfront area where rapid erosion is taking place
B)the distance across open water, over which the wind can blow and generate waves
C)the rotational movements of water particles beneath a passing, surface wave
D)the magical creature who secretly moves sediment about when nobody is looking

Question 16

________ is the turbulent water created by breaking waves.

A)Translatory wave motion
B)Refracted wave
C)Tombolo
D)Surf

Question 17

What is the fetch?

A)Ocean currents that move in a direction parallel to the beach
B)The area of quiet water where deposition is taking place
C)A large area of open water over which wind blows to generate waves
D)Erosion of coastal cliffs creating wave-cut benches

Question 18

The shorelines are ________.

A)ancient geologic oddities, shaped long ago by continent and ocean geometries
B)constant features determined only by sea level and elevation
C)dynamic landscape features balanced between erosion and deposition, by wind and waves
D)principally molded by intermittent geologic cataclysms like earthquakes, landslides, tsunamis, and volcanic eruptions

Question 19

Swash and backwash describe ________.

A)the oscillatory movement of water beneath a passing wave
B)the swirling action and sand movements produced when a shallow water wave impinges on an shallow offshore bar
C)the onshore and offshore movement of water relative to the beach by turbulent surf
D)the forward and backward water movements as storm waves reflect from a seawall or groin

Question 20

What is the wave base?

A)Water depth equal to 1/2 the distance between successive waves
B)Wave height equal to 1/2 the distance between successive waves
C)The minimum elevation of a wave before it will start to curl
D)The distance up the shore where waves can erode

Question 21

Water movement and sand transport parallel to the beach are fundamentally caused by ________.

A)strong, offshore winds creating a pileup of water along the beach front
B)deep-water waves breaking offshore
C)waves impinging obliquely onto a beach
D)a long fetch parallel to the beach

Question 22

________ currents move sand and water parallel to the beach.

A)Reflected
B)Translational
C)Longshore
D)Ebb tide

Question 23

How much do moonrise and the time of highest tide change each day?

A)5 minutes later
B)29 minutes earlier
C)50 minutes later
D)5 hours later

Question 24

Where is Canada's greatest tidal range?

A)Richards Island, NWT along the western Arctic shore
B)The Gulf of St.Lawrence along the eastern townships of Quebec
C)Minas Basin, Bay of Fundy, Nova Scotia
D)Hudson Bay near Moose Factory Ontario

Question 25

Incoming waves slow down and rotate toward an orientation of being parallel to the shoreline.This process is known as ________.

A)refluxing
B)refraction
C)reflection
D)relaxing

Question 26

Longshore currents and sediment transport result from which situation?

A)Incoming wave crests are parallel to the shoreline.
B)Incoming wave crests are slightly oblique to the shoreline.
C)Incoming wave crests are perpendicular to the shoreline.
D)Incoming wave crests are non-existent.

Question 27

Which one of the following is not directly related to wave refraction?

A)Erosional energy is focused on headland areas protruding from the beach.
B)Wave speeds decrease as waves enter shallow water.
C)Deposition is concentrated in bays and protected estuaries.
D)Ebb tidal currents carry large quantities of sand from estuaries to the seaward side of a barrier island system.

Question 28

Where is wave attack the strongest?

A)against the sides and ends of headlands
B)in mid ocean before waves shoal and slow down
C)in the unprotected middle of bays and estuaries
D)on the crest of the beach berm

Question 29

How great can the speed of tidal currents be, such as during spring tides off the coast of Brittany in France?

A)2 km/hr
B)10 km/hr
C)20 km/hr
D)100 km/hr

Question 30

A(n)________ current forms during an incoming or rising tide.

A)flood
B)drift
C)rip
D)ebb

Question 31

What term describes the bending of waves?

A)Reflection
B)Oscillation
C)Refraction
D)Frequency

Question 32

What causes the pair of tidal bulges?

A)One is caused by the pull of the moon, the other by the sun.
B)The east and west shores of the Americas pushing the water out of the way like giant mixer blades.
C)The larger one closest to the Moon is gravitational; 180° away it is inertial.
D)The shape of the whole Earth gets deformed into a flattened ellipsoid by the Moon's gravity; the other bulge is due to centrifugal force bending the rocks back but delayed by a quarter revolution.

Question 33

Where is the world's greatest tidal range?

A)Belize in the tropics
B)Minas Basin, Bay of Fundy, Nova Scotia
C)The Coast of Brittany in France
D)Greenland's north coast

Question 34

________ form when waves that approach the beach at an angle and produce a net current direction that is parallel to the shore, resulting in beach drift.

A)Refraction
B)Rip Currents
C)Eddies
D)Longshore currents

Question 35

________ not the direct result of prevailing longshore current action.

A)Transport of sand along the beach is
B)Building and extension of spits are
C)Closing off of small estuaries by baymouth bars is
D)Fracturing, shattering, and abrasion of rock at the base of a wave-cut cliff are

Question 36

A(n)________ current is a tidal current advancing into a shallow coastal zone, as it flows through a strait or inlet into a bay or estuary.

A)spring
B)flood
C)ebb
D)forward

Question 37

What is the path followed by a sand grain from a succession of waves impinging obliquely onto a beach?

A)A path parallel to the beach, but well offshore as sand is only moved by longshore currents not by breaking waves.
B)A sawtooth path, driven obliquely up the beach face with the swash then straight down the beach face with the backwash.
C)A straight path, right at the shoreface, pushed along parallel to the beach by the breaking wave.
D)Perpendicular to the wave front, obliquely up the beach on the swash, then reflected out at an opposite but equal angle with the backwash.

Question 38

How does refraction affect the shape of incoming waves along a beach?

A)As the waves move into shallower water, the angle between the wave crests (troughs)and the shoreline decreases.
B)As the waves move into shallower water, the angle between the wave crests (troughs)and the shoreline increases.
C)As the waves move into shallower water, the wave slows down and the crests spread farther apart.
D)As the waves move into shallower water, the wave loses energy to the seabed, decreasing the wave height.

Question 39

Which of the following is true regarding the gravitational forces affecting Earth?

A)The lunar attraction is more than that of the Sun.
B)The solar attraction is about twice that of the Moon.
C)The solar and lunar gravitational attractive forces are about the same magnitude.
D)The gravitational forces of each vary depending upon seasons on Earth.

Question 40

The net longshore movement of water, and transport of sand parallel to the beach, are fundamentally caused by ________.

A)a long fetch parallel to the beach
B)deep-water waves breaking in the nearby offshore region creating rips
C)waves refracting and breaking obliquely onto a beach
D)offshore winds creating a pileup of water and a stronger backwash than swash

Question 41

Associated with gaps in a barrier island, a tidal delta is deposited ________.

A)on the estuarine side of a tidal inlet
B)on the seaward side of a tidal inlet
C)in the water gap following stream piracy
D)by major sand movements during neap tides

Question 42

What is the seaward limit of the offshore zone?

A)the barrier island
B)the beach berm
C)fair weather wave base
D)the sea arch

Question 43

Which one of the following coastlines would typically have bedrock features such as wave-cut cliffs, sea stacks, sea arches, and wave-cut platforms?

A)one where bedrock is vigorously eroded in the surf zone as sea level rises
B)one where unconsolidated sediments are being eroded as sea level falls
C)one where a bedrock wave-cut cliff is rapidly retreating inland as sea level falls
D)one where unconsolidated sediments are being rapidly deposited as sea level rises

Question 44

A ________ migrates inland as a wave-cut platform is extended.

A)wave-cut cliff
B)sea stack
C)sea arch
D)wave-cut barrier dune

Question 45

What is the landward limit of the shoreface zone?

A)the backshore
B)the beach berm
C)the low tide line
D)stabilized dunes

Question 46

Relative to shoreline, provided sea level ________, irregularities along a coast can be gradually smoothed out by the combined processes of erosion and deposition.

A)gradually falls
B)gradually rises
C)remains stable
D)rapidly falls

Question 47

A natural sand bar or sand/gravel ridge exposed at low tide that connects one island to another island, or an island to the mainland, is called a ________.

A)spit
B)tombolo
C)sand groin
D)jetty barrier

Question 48

Where does most active sediment transport occur?

A)on the beach face by winds
B)in the shoreface zone by breaking waves and longshore currents
C)in the longshoreman's zone by stevedores
D)the offshore zone by pelagic currents

Question 49

The foreshore zone is ________.

A)found in estuaries behind barrier islands
B)landward of stabilized dunes with permanent vegetation
C)the stable part of the beach above the high-tide zone
D)where the swash and backwash dominate between the low-tide and high-tide zones

Question 50

The backshore zone is ________.

A)found in estuaries behind barrier islands
B)landward of stabilized dunes with permanent vegetation
C)the stable part of the beach above the high-tide zone
D)where the swash and backwash dominate between the low-tide and high-tide zones

Question 51

What is a berm?

A)flat-topped platforms of sand adjacent to dunes or cliffs
B)area landward of the high-tide shoreline
C)wet, sloping surface of the beach
D)build-up of sand where a stream meets the sea

Question 52

Much of the sediment deposited in the underwater portion of the coastal profile is caused by ________.

A)longshore currents
B)rip currents
C)storms
D)tidal deltas

Question 53

How are spits and baymouth bars formed?

A)Sand is transported by longshore currents and deposited where energy decreases.
B)A headland is eroded and the sand is deposited in an offshore basin.
C)Sand eroded from a wave-cut cliff is deposited around sea stacks and arches.
D)Wave erosion cuts away both sides of a long sand bar, leaving a sand ridge aligned parallel to the shore.

Question 54

How big are most barrier islands?

A)1-5 kilometres wide by 15-30 kilometres long
B)10-25 kilometres wide by 75-100 kilometres long
C)>100 kilometres wide by > 350 kilometres long
D)1-5 metres wide by 15-30 metres long

Question 55

Erosional retreat of a(n)________ leads to enlargement and inland extension of a wave-cut platform.

A)wave-cut tombolo
B)wave-cut cliff
C)wave-cut barrier beach
D)offshore, wave-cut, breakwater bar

Question 56

A baymouth bar is ________.

A)a sand deposit extending from a headland partway across the entrance to a bay
B)a sand deposit on the estuary side of gap in a barrier island
C)a sand deposit on the seaward side of a tidal inlet to a large estuary
D)a sand bar extending across the mouth blocking a former inlet to a bay or estuary

Question 57

A ________ is an isolated remnant of bedrock standing above a wave-cut platform.

A)sea spit
B)sea rampart
C)hoodoo
D)sea stack

Question 58

A ________ extends partway across the mouth of a bay or estuary.

A)spit
B)jetty
C)barrier island
D)sand tongue

Question 59

Which active landform is most common along the Texas-Gulf of Mexico coast?

A)barrier islands
B)deltas
C)sea stacks
D)sombreros

Question 60

What does the following sequence signify? Mud overlain by hummocky, crossbedded sand overlain by swaley, crossbedded sand overlain by parallel, tabular bedded, laminated sand overlain by sand with large scale crossbedding.

A)erosional or retreating shoreline at constant sea level
B)falling sea level or buildup of a sandy shore into deeper water
C)rising sea level or migration of a delta away from the area
D)rising sea level with a nearby glacial advance

Question 61

What current geologic processes ultimately doom any attempts to stabilize and preserve shorelines within a century or so?

A)global plate motions and tectonic shifts
B)gradual sea level rise of 1-2 mm/year related to global warming
C)increasing storm severity
D)loss of river discharge from dams and water use on most major rivers

Question 62

________ is an economically viable long-range solution to beach preservation only where there is dense development, large supplies of sand, low wave energy, and reconcilable environmental issues.

A)Abandonment and relocation
B)Beach nourishment
C)Breakwater and seawall construction
D)Foreshore garbage dumping

Question 63

The shoreline represents an interface between the land, sea, and air.

Question 64

________ are constructed parallel to the shoreline and designed to reflect wave energy out to sea.

A)Groins and jetties
B)Seawalls and breakwaters
C)Barrier islands
D)Tidal deltas

Question 65

The dominant effect of the late Pleistocene sea level change was shoreline advance around the globe.

Question 66

Low initial costs and low maintenance costs, low potential for storm damages, and low negative environmental impact are consequences of policies to ________.

A)prohibit coastal development, build nothing but grass shacks, put a moratorium on insurance, declare victory over the sea, and retreat from the coastline
B)promote coastal development, build massive, hardened structures to stop all but the most powerful storm waves
C)allow coastal development, make a long-term commitment to beach nourishment
D)fly to Tahiti

Question 67

________ are constructed perpendicular to the shoreline and designed to interrupt beach drift and longshore currents that "change" shorelines irrespective of human plans and foreshore engineering works.

A)Groins and jetties
B)Seawalls and breakwaters
C)Barrier islands
D)Tidal deltas

Question 68

The main factor in causing mid ocean currents and circulation is wind-drag that moves water along allowing other water to flow in and replace it from the sides or to upwell from depth.

Question 69

High initial costs and eventually high maintenance costs, high potential for storm damage and negative environmental impact are consequences of policies to ________.

A)promote coastal development, build massive, hardened structures to stop all but the most powerful storm waves
B)prohibit coastal development, build nothing but grass shacks, put a moratorium on insurance, declare victory over the sea, and retreat from the coastline
C)allow coastal development, make a long-term commitment to beach nourishment
D)get wasted in Margaritaville!

Question 70

Low initial costs and modest maintenance costs, high potential for storm damage and low to moderate potential for negative environmental effects are consequences of policies to ________.

A)allow coastal development, make a long-term commitment to beach nourishment
B)prohibit coastal development, build nothing but grass shacks, put a moratorium on insurance, declare victory over the sea, and retreat from the coastline
C)promote coastal development, build massive, hardened structures to stop all but the most powerful storm waves
D)don't worry mon, be happy!

Question 71

________ are built more or less parallel to the beach.

A)Seawalls
B)Groins
C)Jetties
D)Caissons

Question 72

________ are structures built perpendicular to the coast along the entrance to navigable tidal inlets, river mouths, or harbours, to stop them from shifting location or filling with sand from beach drift or longshore currents.

A)Groins
B)Jetties
C)Breakwaters
D)Seawalls

Question 73

________ are rough rock or reinforced concrete structures built parallel to the coast to protect boats and harbours from the force of large breaking waves.

A)Breakwaters
B)Groins
C)Jetties
D)Seawalls

Question 74

A ________ is a shoreline stabilization feature that protects shorelines from the pounding of waves by creating an area of quiet water behind it.

A)Groin
B)Seawall
C)Breakwater
D)Jetty

Question 75

Which one of the following would not be a likely effect of a breakwater?

A)increased sand deposition between the beach and the breakwater
B)increased longshore current velocities between the breakwater and the beach
C)deflect and dissipate storm wave energy on the seaward side of the breakwater
D)increased erosion of the beach on one side of the breakwater

Question 76

Sea level has been slowly rising since the large Pleistocene ice sheets melted away.

Question 77

________ are generally built in pairs to preserve the location of a river mouth or harbour entrance.

A)Seawalls
B)Groins
C)Jetties
D)Caissons

Question 78

The leeward side of a groin is ________.

A)a quiet back-water location that fills up with finely laminated muds
B)prone to receive the greatest amount of sand deposition
C)sand starved and particularly prone to erosion
D)the site of massive infections by sand-fleas

Question 79

Over the past few millennia, sea level has been gradually falling.

Question 80

Which one of the following is an artificial (manmade)feature constructed parallel to the shore?

A)sea arch
B)sand spit
C)breakwater
D)barrier island