Question 1

When is hurricane season in the southeastern United States? Why is it then?

Accepted Answer

August and September,because it takes time for ocean water to warm up during the summer and warm water drives the storms.

Question 2

What is beach hardening? What are three examples of techniques used in beach hardening? Why are these not a good solution to preventing erosion of sand on beaches?

Accepted Answer

To prevent erosion,individuals build structures to protect communities,a process called beach hardening.Examples of beach hardening include the following: Seawalls stop the erosion threat with riprap or walls built of either timber or concrete at the back of the beach in front of the property.Although a structure may slow the direct wave erosion of a beach cliff for a while,the waves reflect back off the barrier,stir sand to deeper levels,and carry the adjacent beach sand farther offshore.Groins are the barriers built out into the surf to trap sand from migrating.Riprap walls,or jetties,are sometimes used to maintain navigation channels for boat access into bays,lagoons,and marinas.Jetties that border such channels extend out through the beach,but typically require intermittent dredging to keep a channel open.They also block sand migration along the beach.Breakwaters,built offshore and parallel to the shore,have a similar effect down a beach.They collect sand on their upstream sides,causing deposition in the protected area behind the barrier.Although all of these measures can trap sand,they have the unintended effect of reducing the sand that continues along a beach,which causes beach erosion on the down-current side of a barrier.Effectively,they displace erosion sites to adjacent areas.

Question 3

What do people who live at the top of coastal terraces in the west do to accelerate cliff erosion?

Accepted Answer

They clear driftwood from a beach; that leaves the waves with more energy to erode sand and to erode the sea cliff.They add water to the ground by irrigation,draining water,and sewage drain fields.

Question 4

Why does sea level rise during a near-shore storm?

Accepted Answer

A)  Low atmospheric pressure of the storm permits sea level to rise. 
B)  The winds stir the water in circles, so it rises in the center. 
C)  High pressure in the storm forces the water up. 
D)  Waves cluster together, so the average sea level is higher. 
E)  The gravitational pull of the moon is stronger at such times. 
A)  Low atmospheric pressure of the storm permits sea level to rise. 
B)  The winds stir the water in circles, so it rises in the center. 
C)  High pressure in the storm forces the water up. 
D)  Waves cluster together, so the average sea level is higher. 
E)  The gravitational pull of the moon is stronger at such times.

Question 5

Why do barrier islands gradually migrate landward with time?

Accepted Answer

With sea level rise,the beach

Question 6

What is a rip current? Describe the shoreline's shape as a result of rip currents,and the cause of the distinct shape.

Accepted Answer

As waves pile up water onshore,it stream

Question 7

Explain the processes of wave refraction and longshore drift.What happens to sand as a result of these processes?

Accepted Answer

The part of each wave in shallower water

Question 8

What factors do NOT influence the size of most waves?

Accepted Answer

A)  atmospheric pressure 
B)  wind velocity 
C)  fetch 
D)  time of wind across water 
E)  constant direction of wind across water 
A)  atmospheric pressure 
B)  wind velocity 
C)  fetch 
D)  time of wind across water 
E)  constant direction of wind across water

Question 9

Where does beach sand NOT originate?

Accepted Answer

A)  streams and rivers 
B)  erosion of sea cliffs 
C)  continental shelf as much as 50 km offshore 
D)  longshore drift 
E)  blown by the wind 
A)  streams and rivers 
B)  erosion of sea cliffs 
C)  continental shelf as much as 50 km offshore 
D)  longshore drift 
E)  blown by the wind

Question 10

What is a better solution to erosion than the variety of prevention efforts used on most coasts?

Accepted Answer

Learn to live with actively ev

Question 11

Why are inlets through barrier bars or barrier islands not closed by longshore drift of sand?

Accepted Answer

A)  Such inlets are always the outlets for onshore rivers to reach the sea, so they flush the sand out. 
B)  Rapid flow of water back and forth through the inlet as tides rise and fall keeps it clear. 
C)  Longshore sand drifted into such inlets drops into deeper water, so it drifts out to sea. 
D)  Sand drifted into such inlets encounters brackish water from the inlet and dissolves. 
E)  Sand drifted into such inlets is carried into the lagoon by incoming waves. 
A)  Such inlets are always the outlets for onshore rivers to reach the sea, so they flush the sand out. 
B)  Rapid flow of water back and forth through the inlet as tides rise and fall keeps it clear. 
C)  Longshore sand drifted into such inlets drops into deeper water, so it drifts out to sea. 
D)  Sand drifted into such inlets encounters brackish water from the inlet and dissolves. 
E)  Sand drifted into such inlets is carried into the lagoon by incoming waves.

Question 12

How do sand dunes help maintain sand on a beach?

Accepted Answer

A)  Sand dunes stop the landward advance of the waves. 
B)  People build their houses on top of them, thereby keeping the highest part of the barrier island intact. 
C)  Eroding dune sand spreads over the beach and takes up wave energy. 
D)  Sand dunes don't have much effect; they merely look picturesque. 
E)  They don't help maintain sand on a beach. 
A)  Sand dunes stop the landward advance of the waves. 
B)  People build their houses on top of them, thereby keeping the highest part of the barrier island intact. 
C)  Eroding dune sand spreads over the beach and takes up wave energy. 
D)  Sand dunes don't have much effect; they merely look picturesque. 
E)  They don't help maintain sand on a beach.

Question 13

What factors promote a steeper slope on the active underwater part of the beach?

Accepted Answer

Shallow wa

Question 14

About how far offshore does the active beach extend? Why is that the common limit?

Accepted Answer

To a water depth of about 10 m

Question 15

Why can dune sand,which can easily spread on a beach,be easily eroded during a storm?

Accepted Answer

A)  Dune sand is finer grained and thus more easily moved by waves. 
B)  Dunes are at the upper limit of the waves where the waves can easily drag them back downslope. 
C)  Dune sand stands at a steeper slope than the beach, so it can easily move down to the beach. 
D)  Dune sand is rounder grain than beach sand, so it easily rolls down the beach. 
E)  Dune sand is more angular than beach sand, so the grains do not fit together well. 
A)  Dune sand is finer grained and thus more easily moved by waves. 
B)  Dunes are at the upper limit of the waves where the waves can easily drag them back downslope. 
C)  Dune sand stands at a steeper slope than the beach, so it can easily move down to the beach. 
D)  Dune sand is rounder grain than beach sand, so it easily rolls down the beach. 
E)  Dune sand is more angular than beach sand, so the grains do not fit together well.

Question 16

What is a shore profile? How is it created? Explain the concept of an equilibrium profile in regard to a shore profile.

Accepted Answer

Grain size strongly controls the slope o

Question 17

Where does beach sand originate? (Two quite different places)

Accepted Answer

Streams and rivers,e

Question 18

Why are ocean waves generally larger than those on lakes?

Accepted Answer

A)  Wind directions are much less constant over lakes. 
B)  Winds are always stronger over the ocean. 
C)  Fetch length is much longer in the ocean. 
D)  Ships generating the waves are bigger in the ocean than on lakes. 
E)  Tsunamis are generated in oceans but not in lakes. 
A)  Wind directions are much less constant over lakes. 
B)  Winds are always stronger over the ocean. 
C)  Fetch length is much longer in the ocean. 
D)  Ships generating the waves are bigger in the ocean than on lakes. 
E)  Tsunamis are generated in oceans but not in lakes.

Question 19

Why does the beach slope under water become steeper near shore?

Accepted Answer

A)  The sand grains are finer near shore. 
B)  The bottom has to rise rapidly to merge with the sand of the barrier island. 
C)  Sand from the onshore part of the beach has to drop abruptly because offshore the sand is under water. 
D)  Waves in shallow water drag on the bottom, so they lose energy and need a steeper slope to move the sand. 
E)  The waves are bigger near shore. 
A)  The sand grains are finer near shore. 
B)  The bottom has to rise rapidly to merge with the sand of the barrier island. 
C)  Sand from the onshore part of the beach has to drop abruptly because offshore the sand is under water. 
D)  Waves in shallow water drag on the bottom, so they lose energy and need a steeper slope to move the sand. 
E)  The waves are bigger near shore.

Question 20

Why are once sandy beaches on the West Coast now disappearing?

Accepted Answer

Dams on rivers no longer suppl

When is hurricane season in the southeastern United States? Why is it then?

What is beach hardening? What are three examples of techniques used in beach hardening? Why are these not a good solution to preventing erosion of sand on beaches?

What do people who live at the top of coastal terraces in the west do to accelerate cliff erosion?

Why does sea level rise during a near-shore storm?

Why do barrier islands gradually migrate landward with time?

What is a rip current? Describe the shoreline's shape as a result of rip currents,and the cause of the distinct shape.

Explain the processes of wave refraction and longshore drift.What happens to sand as a result of these processes?

What factors do NOT influence the size of most waves?

Where does beach sand NOT originate?

What is a better solution to erosion than the variety of prevention efforts used on most coasts?

Why are inlets through barrier bars or barrier islands not closed by longshore drift of sand?

How do sand dunes help maintain sand on a beach?

What factors promote a steeper slope on the active underwater part of the beach?

About how far offshore does the active beach extend? Why is that the common limit?

Why can dune sand,which can easily spread on a beach,be easily eroded during a storm?

What is a shore profile? How is it created? Explain the concept of an equilibrium profile in regard to a shore profile.

Where does beach sand originate? (Two quite different places)

Why are ocean waves generally larger than those on lakes?

Why does the beach slope under water become steeper near shore?

Why are once sandy beaches on the West Coast now disappearing?

Natural Hazards and Disasters

Plate Tectonics and Physical Hazards

Earthquakes and Their Causes

Earthquake Prediction and Mitigation

Tsunami

Volcanoes: Tectonic Environments and Eruptions

Volcanoes: Hazards and Mitigation

Landslides and Other Downslope Movements

Sinkholes, Land Subsidence, and Swelling Soils

Weather, Thunderstorms, And Tornadoes

Climate Change

Streams And Flood Processes

Floods And Human Interactions

Hurricanes and Nor’easters

Wildfires

Impact of Asteroids and Comets

The Future: Where Do We Go From Here?

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Exam 14: Waves,Beaches,And Coastal Erosion

When is hurricane season in the southeastern United States? Why is it then?

What is beach hardening? What are three examples of techniques used in beach hardening? Why are these not a good solution to preventing erosion of sand on beaches?

What do people who live at the top of coastal terraces in the west do to accelerate cliff erosion?

Why does sea level rise during a near-shore storm?

Why do barrier islands gradually migrate landward with time?

What is a rip current? Describe the shoreline's shape as a result of rip currents,and the cause of the distinct shape.

Explain the processes of wave refraction and longshore drift.What happens to sand as a result of these processes?

What factors do NOT influence the size of most waves?

Where does beach sand NOT originate?

What is a better solution to erosion than the variety of prevention efforts used on most coasts?

Why are inlets through barrier bars or barrier islands not closed by longshore drift of sand?

How do sand dunes help maintain sand on a beach?

What factors promote a steeper slope on the active underwater part of the beach?

About how far offshore does the active beach extend? Why is that the common limit?

Why can dune sand,which can easily spread on a beach,be easily eroded during a storm?

What is a shore profile? How is it created? Explain the concept of an equilibrium profile in regard to a shore profile.

Where does beach sand originate? (Two quite different places)

Why are ocean waves generally larger than those on lakes?

Why does the beach slope under water become steeper near shore?

Why are once sandy beaches on the West Coast now disappearing?

Natural Hazards and Disasters

Plate Tectonics and Physical Hazards

Earthquakes and Their Causes

Earthquake Prediction and Mitigation

Tsunami

Volcanoes: Tectonic Environments and Eruptions

Volcanoes: Hazards and Mitigation

Landslides and Other Downslope Movements

Sinkholes, Land Subsidence, and Swelling Soils

Weather, Thunderstorms, And Tornadoes

Climate Change

Streams And Flood Processes

Floods And Human Interactions

Hurricanes and Nor’easters

Wildfires

Impact of Asteroids and Comets

The Future: Where Do We Go From Here?

Filters