shorelines

Which one of the following statements regarding active and/or passive margins is NOT true? -Cape Cod represents an active margin, as evidenced by its large sand dunes. -Long, beautiful beaches characterize passive margins. -Subduction commonly occurs along active margins, pushing cliffs upward. -There are not many earthquakes or volcanoes along passive margins. -The shorelines of the east and west coasts of the U.S. look very different.

-Cape Cod represents an active margin, as evidenced by its large sand dunes. *Cape Cod represents a passive margin, not an active one.

An open water wave with a wavelength of 4 meters moves onshore into shallow water. At what depth does the wave begin to touch bottom? Hints 3 meters ½ meter 4 meters 2 meters 1 meter

2 meters *Correct! The depth of water affected by the wave as it comes onshore is one-half the wavelength. With a wavelength of 4 meters, the wave would touch bottom at 2 meters.

How many spring and neap tides will a tide-recording station experience in a given month? 1 to 3 spring tides and 3 to 4 neap tides 3 to 4 spring tides and 1 to 3 neap tides 2 spring tides and 2 neap tides 1 spring tide and 1 neap tide

2 spring tides and 2 neap tides

When will reflection and refraction occur simultaneously? When will reflection and refraction occur simultaneously? A wave will reflect and refract when it encounters a boundary between two layers of different velocity. Waves are always reflecting and refracting, regardless of boundary type or velocity structure. A wave will reflect and refract when it encounters a boundary between a high-velocity layer above a low-velocity layer. A wave will reflect and refract when it encounters a boundary between a low-velocity layer above a high-velocity layer.

A wave will reflect and refract when it encounters a boundary between two layers of different velocity.

Why does the Moon generate larger tidal forces than the Sun? Although the Moon is bigger, the Sun is much closer. Although the Sun is further away, the Moon is much smaller. Although the Moon is further away, the Sun is much smaller. Although the Sun is bigger, the Moon is much closer.

Although the Sun is bigger, the Moon is much closer.

Which way would sediment move if NO beach drift existed? away from shore perpendicular to shore at an angle to shore parallel to shore

At an angle to shore

Once hard stabilization of a coast is initiated by construction of structures such as groins and breakwaters, why is it often necessary to continue building more of these structures? Hints More structures are needed because longshore drift can cause the development of bars at the mouths of rivers on the downcurrent side of the groin. Once the coast is stabilized, more people move to the area and additional structures are necessary. Construction of additional groins prevents the need for beach nourishment. Groins prevent the erosion of bedrock by breaking waves, so more are needed in densely populated areas. Construction of groins and breakwaters disrupts the natural flow of sediments along the coast.

Construction of groins and breakwaters disrupts the natural flow of sediments along the coast. *Correct! Once groins are constructed, currents that move sediment can be starved on the downcurrent side of the groin, causing increased erosion and the need for more structures.

Which of the following describes the general pattern of movement of sand on a shoreline? Hints Net sand movement is at an angle to the shore. Net sand movement is perpendicular to the shore. Receding waves pull the sand out at an angle to the shore. Net sand movement is parallel to the shore. Incoming waves push sand at up the shore perpendicular to the shore.

Net sand movement is parallel to the shore. *The incoming waves push the sand onshore at an angle and the outgoing wave pulls the sand out perpendicular to the shore, resulting in a net movement that is parallel to the shore.

Which of the following statements about reflection and refraction is most accurate? -Reflection is the bouncing of waves, whereas refraction is the bending of waves. -Refraction and reflection are both the bending of waves. -Refraction and reflection are both the bouncing of waves. -Refraction is the bouncing of waves, whereas reflection is the bending of waves.

Reflection is the bouncing of waves, whereas refraction is the bending of waves.

A thin peninsula called a spit extends beyond the bluffs of the outer beach on Cape Cod. What has caused this spit to form? Hints -Barrier islands that migrate are known as spits. -Sand from the bluffs is carried and deposited by longshore currents. -Nor'easter storms cause larger landmasses to erode into long, thin ridges known as spits. -As sea level drops during the winter, shoals are exposed. These are known as spits. -When beach dunes become separated from the mainland by an intervening stream, a spit forms.

Sand from the bluffs is carried and deposited by longshore currents.

Which of the following statements describe what happens to sediment when a longshore current meets a jetty? Choose all that apply. Hints Choose all that apply. Sediment is eroded on the down-current side of the jetty because water is starved of sediment in this location. Sediment is deposited on the up-current side of the jetty because water moves slower in this location. Sediment is eroded on the up-current side of the jetty because the water is starved of sediment in this location. Sediment is deposited on the down-current side of the jetty because water moves slower in this location.

Sediment is eroded on the down-current side of the jetty because water is starved of sediment in this location. Sediment is deposited on the up-current side of the jetty because water moves slower in this location.

Which situation occurs in the downcurrent direction when a groin is constructed on a beach to prevent erosion of a beach by longshore currents? Hints Erosion is completely stopped on the downcurrent side of the groin. Sediment accumulates on the downcurrent side of the groin. Baymouth bars form in the area immediately downcurrent of the groin. Sediment is removed on the downcurrent side of the groin. Barrier islands form on the downcurrent side of the groin

Sediment is removed on the downcurrent side of the groin. *Correct! If sediment starvation occurs with the buildup of sand on the upcurrent side of the groin, sediment erosion occurs on the downcurrent side of the groin.

What is the relationship between wave base and wavelength? The depth of the wave base is three-quarters of the wavelength of the waves. The depth of the wave base is twice the wavelength of the waves. The depth of the wave base is one-and-a-half times the wavelength of the waves. The depth of the wave base is two-thirds the wavelength of the waves. The depth of the wave base is one-half the wavelength of the waves.

The depth of the wave base is one-half the wavelength of the waves.

Why does wave height increase as waves enter shallow water? The energy of the wave must be contained within a smaller water column in shallow water. The energy of the wave must be contained within a larger water column in shallow water. The wavelength of the wave must be contained within a larger water column in shallow water. The wavelength of the wave must be contained within a smaller water column in shallow water.

The energy of the wave must be contained within a smaller water column in shallow water.

Why are high tides found simultaneously on opposite sides of Earth? The ocean water experiencing high tide rotates around Earth on a 12-hour cycle. The ocean water experiencing low tide rotates around Earth on a 12-hour cycle. The tidal bulges occur on both sides of Earth that are perpendicular to the tide-generating body. The tidal bulges occur on both sides of Earth that are aligned with the tide-generating body.

The tidal bulges occur on both sides of Earth that are aligned with the tide-generating body.

Why do ocean waves bend around headlands? The waves have shorter wavelength just in front of the headland, causing the waves to bend. The waves are moving more slowly just in front of the headland, causing the waves to bend. The waves have longer wavelength just in front of the headland, causing the waves to bend. The waves are moving faster just in front of the headland, causing the waves to bend.

The waves are moving more slowly just in front of the headland, causing the waves to bend.

How does water move as waves pass? Water moves linearly in the opposite direction to wave movement. Water moves linearly in the same direction as wave movement. Water moves in a circle in the direction opposite to wave movement. Water moves in a circle in the same direction as wave movement.

Water moves in a circle in the same direction as wave movement.

When a headland of resistant bedrock extends out into the ocean, which statement best describes wave action in proximity to the headland? Hints Wave energy is reflected off the headland. Wave energy hits the headland directly. Wave energy is focused on the headland. Wave energy is deflected away from the headland. Wave energy acts to construct a headland.

Wave energy is focused on the headland. *Correct! As waves approach a headland, they are refracted or bent around the headland, causing energy to be focused on three sides of the headland.

Which of the following statements about wave period is most accurate? Wave period is the inverse of wave height. Wave period is the inverse of wave amplitude. Wave period is the inverse of wavelength. Wave period is the inverse of wave frequency.

Wave period is the inverse of wave frequency.

How does wave refraction at headlands affect deposition and erosion? Wave refraction at the headland decreases erosion at the headland and causes deposition in adjacent bays. Wave refraction at the headland decreases deposition at the headland and causes erosion in adjacent bays. Wave refraction at the headland increases deposition at the headland and causes erosion in adjacent bays. Wave refraction at the headland increases erosion at the headland and causes deposition in adjacent bays.

Wave refraction at the headland increases erosion at the headland and causes deposition in adjacent bays.

How are wave period and wavelength related? Waves with longer periods have shorter wavelengths. Waves with shorter periods have longer wavelengths. Waves with shorter periods have shorter wavelengths.

Waves with shorter periods have shorter wavelengths.

Which process is directly responsible for the development of notches, cliffs, and platforms? Hints abrasion relocation beach nourishment reflection rip currents

abrasion *Correct! As wave energy moves particles back and forth, abrasion erodes bedrock surfaces, creating notches, cliffs, and platforms.

Which pattern best describes the motion of water particles in a wave in the open ocean? Hints zigzag pattern up and down the beach circular orbit up and down compression-dilation back and forth

circular orbit

What is the name of the gigantic boulders left behind as the glaciers receded? Hints kettles moraines spits tills erratics

erratics

In the long term, what do beach drift and longshore current do? move sediment up to the shoreline Move sediment away from the shoreline Move sediment perpendicular to the shoreline Move sediment parallel to the shoreline

move sediment parallel to the shoreline

What do we call the tide that occurs when destructive interference between lunar and solar bulges produces a small tidal range? pean tide fall tide neap tide spring tide

neap tide

Which pattern of particle movement occurs when wave movement is oblique to the beach? Hints A jetty forms. Particles move on the beach in a zigzag pattern. Particles are removed from the beach. A groin could be deposited. Particles move perpendicularly to the beach.

particles move on the beach in a zigzag pattern

Which term is used by geologists to identify the time interval between the passage of successive wave crests or troughs? wavelength height drift fetch period

period

If the sediment that makes up the beaches of Cape Cod were to lithify, what kind of rock would it become? Hints Rock Gypsum limestone shale sandstone basalt

sandstone

Which feature results from the collapse of a sea arch? Hints baymouth bar spit barrier island seawall sea stack

sea stack *Correct! When a sea arch collapses, a portion of the resistant bedrock remains isolated from the shore, producing a sea stack.

What do we call the tide that occurs when constructive interference between lunar and solar bulges produces a large tidal range? neap tide fall tide spring tide pean tide

spring tide

What is refraction? the bending of waves due to a change in wave velocity the bending of waves due to a change in wave amplitude the bending of waves due to a change in wavelength the bending of waves due to a change in wave phase

the bending of waves due to a change in wave velocity

What is the wavelength? the highest part of the wave the distance between consecutive wave crests or troughs the time it takes for one wavelength of a wave to pass a particular point the distance between the highest and lowest part of the wave the lowest part of the wave

the distance between consecutive wave crests or troughs

What is the wave height? the lowest part of the wave the distance between the highest and lowest part of the wave the distance between consecutive wave crests or troughs the highest part of the wave the time it takes for one wavelength of a wave to pass a particular point

the distance between the highest and lowest part of the wave

What is the crest of a wave? the lowest part of the wave the time it takes for one wavelength of a wave to pass a particular point the highest part of the wave the distance between the highest and lowest part of the wave the distance between consecutive wave crests or troughs

the highest part of the wave

What is the wave base? the upper limit of wave-induced motion in the water the lower limit of wave-induced motion in the water the closest distance a wave can get to shore before breaking the furthest distance a wave can get to shore before dissipating

the lower limit of wave-induced motion in the water

What is the trough of a wave? the lowest part of the wave the distance between the highest and lowest part of the wave the highest part of the wave the distance between consecutive wave crests or troughs the time it takes for one wavelength of a wave to pass a particular point

the lowest part of the wave

What are tides? the regular daily rises and falls in sea level caused by the gravitational attraction of the Sun on Earth the regular daily rises and falls in sea level caused by the gravitational attraction of the Moon on Earth the regular weekly rises and falls in sea level caused by the gravitational attraction of the Moon and Sun on Earth the regular weekly rises and falls in sea level caused by the gravitational attraction of the Moon on Earth the regular daily rises and falls in sea level caused by the gravitational attraction of the Moon and Sun on Earth

the regular daily rises and falls in sea level caused by the gravitational attraction of the Moon and Sun on Earth

What is the wave period? the distance between the highest and lowest part of the wave the distance between consecutive wave crests or troughs the lowest part of the wave the highest part of the wave the time it takes for one wavelength of a wave to pass a particular point

the time it takes for one wavelength of a wave to pass a particular point

How will a wave change as it moves from a layer of higher velocity into a lower layer of lower velocity? The wave will bend toward the right. The wave will stop moving. The wave will bend toward the left. The wave will not bend.

the wave will bend toward the left

How will a wave change as it moves from a layer of lower velocity into a lower layer of higher velocity? The wave will bend toward the right. The wave will stop moving. The wave will bend toward the left. The wave will not bend.

the wave will bend toward the right

If the wave period changes so that it is half its original value, how does this change the wavelength? Hints The wavelength will be twice as long. The wavelength will be eight times as long. The wavelength will be four times as long. The wavelength will not be affected. The wavelength will also be half as long.

the wavelength will also be half as long. *correct! wavelength and period are directly proportional

What is the longshore current? water forced by waves to move away from the shore water forced by waves to move along the shore water forced by longshore drift to move along the shore water forced by longshore drift to move away from the shore

water forced by waves to move along the shore

How does wave amplitude change with depth in water? Wave amplitude decreases as depth increases. Wave amplitude increases as depth increases. Wave amplitude remains the same as depth increases.

wave amplitude decreases as depth increases

Occasionally, when a sea stack is formed, accumulations of sand are deposited behind it, producing a tombolo. Which process is responsible for the creation of the tombolo? Hints rip currents abrasion gyres wave refraction Coriolis effect

wave refraction *Right! After the formation of the sea stack, waves are bent (refracted) around the obstruction due to the shallower water. Sediment accumulates in the relatively quiet area behind the sea stack as a tombolo.

Which of the following is a characteristic example of an emergent coastline? Hints wave-cut platform drowned river mouth estuary highly irregular coastline a coast where the adjacent land is subsiding

wave-cut platform

Which term is used to define the distance between successive wave crests or troughs? Hints wave height fetch wavelength wave period wind speed

wavelength

When waves approach shore and touch bottom, what happens to the wave form? wavelength decreases and height increases wavelength decreases wavelength increases and height decreases fetch increases wave height increases

wavelength decreases and height increases