1. Chapter 10 Preview Section 1 Shoreline Erosion and Deposition
Agents of Erosion and Deposition
Preview
Section 1 Shoreline Erosion and Deposition
Section 2 Wind Erosion and Deposition
Section 3 Erosion and Deposition by Ice
Section 4 Erosion and Deposition by Mass Movement
Concept Map

2. Section 1 Shoreline Erosion and Deposition
Chapter 10
Bellringer
Think about where sand comes from. Then, write a short story or poem that tells how sand is supplied by rivers and how it is moved along the coast by the action of the waves.
Write your story or poem in your science journal.

3. Chapter 10 What You Will Learn
Section 1 Shoreline Erosion and Deposition
Chapter 10
What You Will Learn
Energy from waves crashing against rocks affects shorelines.
Shoreline features are created by wave erosion.
Waves deposit sediment at the shore to form beaches.

4. Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Energy
Two ingredients are needed to make sand: rock and energy.
When waves crash into rock over long periods of time, the rock breaks down into smaller pieces that are called sand.

5. Chapter 10 Wave Energy, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Energy, continued
The formation and movement of sand by wave erosion and deposition shape the shoreline.
A shoreline is the place where land and a body of water meet.
Waves usually play a major part in shaping a shoreline.

6. Chapter 10 Wave Energy, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Energy, continued
As wind moves across the ocean surface, it makes disturbances called waves.
The size of a wave depends on the strength of the wind and the amount of time that it blows.
The stronger the wind, and the longer it blows, the larger the waves are.

7. Chapter 10 Wave Energy, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Energy, continued
Wind that results from summer hurricanes and severe weather storms makes large waves that cause dramatic shoreline erosion.
Waves may travel hundreds or thousands of kilometers from a storm before reaching shore.
Some of the largest waves hitting the California coast were produced by storms in Australia.

8. Chapter 10
Agents of Erosion and Deposition
Ocean Wave Energy

9. Chapter 10 Wave Energy, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Energy, continued
When you drop a pebble into a pond, it makes many ripples.
Waves, like ripples, move in groups called wave trains.
The waves in a wave train are separated by a period of time called a wave period.

10. Chapter 10 Wave Energy, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Energy, continued
As wave trains travel from their source, they move uninterrupted through deep ocean water.
When a wave reaches shallow water, the bottom of the wave drags against the sea floor.
The top of the wave moves faster than the bottom, and the wave gets taller.

11. Chapter 10 Wave Energy, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Energy, continued
Eventually, the wave gets so tall that it can’t support itself.
At that point, it begins to curl and break.
Breaking waves are known as surf.

12. Chapter 10 Wave Energy, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Energy, continued
A tremendous amount of energy is released when waves break.
Waves can break off large boulders and wash away sand.
The action of waves breaks rock into smaller and smaller pieces.

13. Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Erosion
Wave erosion produces a variety of features along a shoreline.
Sea cliffs form when waves erode and undercut rocks to make steep slopes.
The rate at which sea cliffs erode depends on the hardness of the rock and the energy of the waves.

14. Wave Erosion, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Erosion, continued
Large waves caused by storms transfer far more energy than average-sized waves do.
The energy is so powerful that it can remove chunks of rock.
Much of the erosion responsible for landforms along the shoreline takes place during storms.

15. Wave Erosion, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Erosion, continued

16. Wave Erosion, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Erosion, continued

17. Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Deposits
Waves carry a variety of materials, including sand, rock fragments, coral, and shells.
A beach is any area of shoreline that is made up of material deposited by waves.
Some beach material is also deposited by rivers and then moved down the shoreline by waves.

18. Wave Deposits, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Deposits, continued
Not all beaches are made of sand.
The type of beach material depends on its source.
The size and shape of beach material depends on how far the material traveled.

19. Wave Deposits, continued
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Wave Deposits, continued
The color of beach material depends on the material’s source.
Light-colored sand is the most common beach material.
Much of this sand is made of the mineral quartz.

20. Wave Deposits, continued
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Wave Deposits, continued
Most quartz comes from eroded sandstone.
Many tropical beaches are made of finely ground white coral.
Black sand beaches are made of eroded lava.

21. Wave Deposits, continued
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Wave Deposits, continued
California has both rocky and sandy shores.
Rocky beaches commonly form where mountains or cliffs meet the ocean.
Sandy beaches commonly form on the edges of more gently sloping land.

22. Wave Deposits, continued
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Wave Deposits, continued
The mineral composition of California beaches also varies.
The sand in Humboldt County is charcoal gray and comes from eroded shale cliffs nearby.
The white sand at Carmel is made of quartz and feldspar.

23. Wave Deposits, continued
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Wave Deposits, continued
The amount of sand present on a beach can change between seasons.
In California, beaches can become narrower in winter as large winter storm waves erode sand.
Much of the eroded sand is trapped by offshore sandbars and returned by waves during the summer.

24. Wave Deposits, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Deposits, continued
When waves crash on the beach head-on, the water flows back to the ocean underneath new incoming waves.
This movement, called an undertow, carries sand and rock away from shore.

25. Wave Deposits, continued
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Chapter 10
Wave Deposits, continued
When water travels parallel to the shoreline very near shore, the current is called a longshore current.
Longshore currents are caused by waves hitting the shore at an angle.
Waves that break at oblique angles carry sediment along the coast.

26. Wave Deposits, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Deposits, continued
Waves wash the sand parallel to the direction in which they break.
But the return water flow brings sand directly down the slope of the beach.
This process results in a zigzag motion of sand.

27. Wave Deposits, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Deposits, continued

28. Wave Deposits, continued
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Wave Deposits, continued
Longshore currents transport most of the sediment (sand) in beach environments.
This process both tears down and builds up the coastline.
Unfortunately, longshore currents also spread trash and other ocean pollution along shore.

29. Wave Deposits, continued
Section 1 Shoreline Erosion and Deposition
Chapter 10
Wave Deposits, continued
When waves erode material from the shoreline, longshore currents can transport and deposit this material offshore.
This process creates landforms in open water.
A sandbar is an underwater or exposed ridge of sand, gravel, or shell material.

30. Wave Deposits, continued
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Wave Deposits, continued
A barrier spit is an exposed sandbar that is connected to the shoreline.
Cape Cod, Massachusetts, is an example of a barrier spit.
A barrier island is a long, narrow island usually made of sand that forms parallel to the shoreline a short distance offshore.

31. Chapter 10 California Islands
Section 1 Shoreline Erosion and Deposition
Chapter 10
California Islands
The Channel Islands are located off the southern California coast. (Catalina Island)
These islands formed millions of years ago.
They are thought to have once been part of mainland mountain ranges.

32. California Islands, continued
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California Islands, continued
Now, the Channel Islands are separated from the mainland by the Santa Monica Channel and the San Pedro Channel.
Islands such as the Channel Islands protect coastlines from storm waves.
They can also be sanctuaries for birds and marine mammals.

33. Section 2 Wind Erosion and Deposition
Chapter 10
Bellringer
What forces do you think help shape the landscape?
Record your thoughts in your science journal.

34. Chapter 10 What You Will Learn
Wind erosion happens through saltation, deflation, and abrasion.
Wind can erode and deposit differing amounts and sizes of material, depending on the wind speed.

35. Section 2 Wind Erosion and Deposition
Chapter 10
Wind Erosion
When wind moves soil, sand, and rock particles, it acts as an agent of erosion.
Areas that have little plant cover are vulnerable to wind erosion.
These areas lack plant roots, which can anchor sand and soil in place.

36. Wind Erosion, continued
Section 2 Wind Erosion and Deposition
Chapter 10
Wind Erosion, continued
Saltation
Large grains of soil, sand, and rock are moved by saltation.
Saltation is the skipping and bouncing movement of sand-sized particles in the direction that the wind is blowing.

37. Wind Erosion, continued
Section 2 Wind Erosion and Deposition
Chapter 10
Wind Erosion, continued
When sand grains knock into each other, they roll and bounce forward.

38. Wind Erosion, continued
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Wind Erosion, continued
Deflation
The removal of fine sediment by wind is called deflation.
During deflation, wind removes the top layer of fine sediment and soil.

39. Wind Erosion, continued
Section 2 Wind Erosion and Deposition
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Wind Erosion, continued
Deflation leaves behind rock fragments that are too heavy to be lifted by the wind.
Deflation may cause the formation of desert pavement, which is a surface that is made of pebbles and small broken rocks.

40. Wind Erosion, continued
Section 2 Wind Erosion and Deposition
Chapter 10
Wind Erosion, continued
In areas that have little plant cover, the wind may scoop out depressions in the landscape.
These depressions are called deflation hollows.

41. Wind Erosion, continued
Section 2 Wind Erosion and Deposition
Chapter 10
Wind Erosion, continued
Abrasion
The grinding and wearing down of rock surfaces by other rock or by sand particles is called abrasion.
Abrasion happens in areas where there are strong winds, loose sand, and soft rocks. Abrasion helps to erode, polish, and smooth rocks.

42. Wind-Deposited Materials
Section 2 Wind Erosion and Deposition
Chapter 10
Wind-Deposited Materials
Wind carries and deposits sediment in much the same way that rivers do.
The amount and size of particles that wind can carry depends on wind speed.
As wind speed slows, particles are deposited according to weight, from heaviest to lightest.

43. Wind Deposited Materials, continued
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Chapter 10
Wind Deposited Materials, continued
Dunes
When wind hits an obstacle, it slows and deposits particles.
As material builds up, the obstacle gets larger.
This slows the wind even more, and causes more material to be deposited.

44. Wind Deposited Materials, continued
Section 2 Wind Erosion and Deposition
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Wind Deposited Materials, continued
Eventually, the original obstacle is buried.
The mounds of deposited sand on top of the obstacle are called dunes.
Dunes are common in sandy deserts and along the sandy shores of lakes and oceans.

45. Wind Deposited Materials, continued
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Wind Deposited Materials, continued
California Dunes
California is home to several major dune formations.
These dunes are in coastal and desert areas.
The Algodones Sand Dunes cover one thousand square miles.

46. Wind Deposited Materials, continued
Section 2 Wind Erosion and Deposition
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Wind Deposited Materials, continued
The Movement of Dunes
Generally, dunes move in the same direction the wind is blowing.
Wind conditions determine the dune’s shape and size.

47. Wind Deposited Materials, continued
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Wind Deposited Materials, continued
A dune usually has a gently sloped side and a steeply sloped side.

48. Wind Deposited Materials, continued
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Wind Deposited Materials, continued
Usually, the gently sloped side faces into the wind.
Wind constantly moves material up this side of the dune.
As sand moves over the crest of the dune, it slides down the slip face and makes a steep slope.

49. Section 3 Erosion and Deposition by Ice
Chapter 10
Bellringer
Imagine that you are standing on a glacier. Write a few sentences that describe the glacier. Then, explain why you think glaciers are often called “rivers of ice.”
Write about the experience in your science journal.

50. Chapter 10 What You Will Learn
Section 3 Erosion and Deposition by Ice
Chapter 10
What You Will Learn
As glaciers move, they form a variety of landforms by removing rock and soil.
Glaciers deposit rock material when they melt or retreat.

51. Glaciers—Rivers of Ice
Section 3 Erosion and Deposition by Ice
Chapter 10
Glaciers—Rivers of Ice
A glacier is an enormous mass of moving ice.
Continental glaciers spread across entire continents and produce flattened landscapes.
Alpine glaciers form in mountainous areas and produce rugged landscapes.

52. Glaciers—Rivers of Ice, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Glaciers—Rivers of Ice, continued
Glaciers form in areas that retain snow year-round.
In polar regions and high elevations, layers of snow build up year after year.
Over time, the weight of the snow compresses and packs the lower layers, which eventually become ice.

53. Glaciers—Rivers of Ice, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Glaciers—Rivers of Ice, continued
How Glaciers Move
Gravity causes glaciers to flow slowly, like “rivers of ice.”
When enough ice builds up on a slope, the ice begins to move downhill.

54. Glaciers—Rivers of Ice, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Glaciers—Rivers of Ice, continued
Thick glaciers move faster than thin glaciers do.
The steeper the slope is, the faster the glaciers move.
Glaciers move by sliding and flowing.

55. Landforms Created by Glaciers
Section 3 Erosion and Deposition by Ice
Chapter 10
Landforms Created by Glaciers
As a glacier moves, rocks below and beside the glacier are broken and moved.
Grooves may form in the rock over which the glacier slides as rocks are dragged beneath the glacier.

56. Landforms Created by Glaciers, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Landforms Created by Glaciers, continued

57. Types of Glacial Deposits
Section 3 Erosion and Deposition by Ice
Chapter 10
Types of Glacial Deposits
As a glacier melts, it drops all of the material it is carrying.
Glacial drift is the term used to describe all material carried and deposited by glaciers.
Glacial drift is divided into till and stratified drift.

58. Types of Glacial Deposits, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Types of Glacial Deposits, continued
Till Deposits
Unsorted rock material that is deposited directly by ice when it melts is called till.
Unsorted means that the till is made up of rock material of different sizes—from large boulders to fine sediment.

59. Types of Glacial Deposits, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Types of Glacial Deposits, continued
When the glacier melts, the unsorted material is deposited on the surface of the ground.
The most common till deposits are moraines.
Moraines generally form ridges along the edges of glaciers.

60. Types of Glacial Deposits, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Types of Glacial Deposits, continued
Moraines form when glaciers carry material to the front of and along the sides of the ice.
As the ice melts, the glacier drops the sediment and rock that it is carrying.
This dropped material forms different kinds of moraines.

61. Types of Glacial Deposits, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Types of Glacial Deposits, continued

62. Types of Glacial Deposits, continued
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Types of Glacial Deposits, continued
Stratified Drift
When a glacier melts, streams form that carry rock material away from the shrinking glacier.
A glacial deposit that is sorted into layers based on the size of the rock material is called stratified drift.

63. Types of Glacial Deposits, continued
Section 3 Erosion and Deposition by Ice
Chapter 10
Types of Glacial Deposits, continued
Streams deposit sorted material in front of the glacier in an outwash plain.
Sometimes, a block of ice is left in the outwash plain as the glacier retreats.

64. Types of Glacial Deposits, continued
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Chapter 10
Types of Glacial Deposits, continued
As the ice melts, sediment builds up around it, and a depression called a kettle forms.
Kettles commonly fill with water to form lakes or ponds.

65. Glacial Drift: Stratified Drift and Till
Chapter 10
Agents of Erosion and Deposition
Glacial Drift: Stratified Drift and Till

66. Section 4 Erosion and Deposition by Mass Movement
Chapter 10
Bellringer
Where would a warning sign like this be necessary or useful?
Write your answer in your science journal.

67. Chapter 10 What You Will Learn
Section 4 Erosion and Deposition by Mass Movement
Chapter 10
What You Will Learn
The angle of repose determines whether mass movement will happen.
Gravity causes rock falls, landslides, mudflows, and creep.

68. Chapter 10 Angle of Repose
Section 4 Erosion and Deposition by Mass Movement
Chapter 10
Angle of Repose
Mass movement is the movement of any material, such as rock, soil, or snow, downslope.
Mass movement plays a major role in shaping Earth’s surface.
Mass movement occurs when the slope of surface material is greater than the angle of repose.

69. Angle of Repose, continued
Section 4 Erosion and Deposition by Mass Movement
Chapter 10
Angle of Repose, continued
The angle of repose is the steepest angle, or slope, at which loose material no longer moves downslope.
Characteristics of surface material, such as weight, size, shape, and moisture level, determine the angle of repose.

70. Angle of Repose, continued
Section 4 Erosion and Deposition by Mass Movement
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Angle of Repose, continued

71. Chapter 10 Rapid Mass Movement
Section 4 Erosion and Deposition by Mass Movement
Chapter 10
Rapid Mass Movement
The most destructive mass movements happen suddenly and rapidly.
A rock fall happens when loose rocks fall down a steep slope.
Steep slopes sometimes form when a road is built through mountainous areas.

72. Rapid Mass Movement, continued
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Chapter 10
Rapid Mass Movement, continued
Loosened and exposed rocks tend to fall as a result of gravity.
A landslide is the sudden and rapid movement of a large amount of material downslope.
Landslides can carry away plants and animals or bury their habitats.

73. Rapid Mass Movement, continued
Section 4 Erosion and Deposition by Mass Movement
Chapter 10
Rapid Mass Movement, continued
A slump is the most common kind of landslide.
Slumping occurs when a block of material moves downslope over a curved surface.
Heavy rains, deforestation, construction on unstable slopes, and earthquakes increase the chances of landslides.

74. Rapid Mass Movement, continued
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Rapid Mass Movement, continued
A rapid mass movement of mud is a mudflow.
Mudflows happen when a large amount of water mixes with soil and rock.
The water causes the slippery mass of mud to flow rapidly downslope.

75. Rapid Mass Movement, continued
Section 4 Erosion and Deposition by Mass Movement
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Rapid Mass Movement, continued
Mudflows commonly happen in mountainous regions when a long dry season is followed by heavy rains.
Deforestation and the removal of vegetation often result in mudflows.
A mudflow can cover everything in its path.

76. Chapter 10
Agents of Erosion and Deposition
Rapid Mass Movement

77. Chapter 10 Slow Mass Movement
Section 4 Erosion and Deposition by Mass Movement
Chapter 10
Slow Mass Movement
The extremely slow movement of material downslope is called creep.
All rock and soil on slopes is experiencing some form of creep.
Many factors contribute to creep.

78. Slow Mass Movement, continued
Section 4 Erosion and Deposition by Mass Movement
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Slow Mass Movement, continued
Water loosens soil and allows the soil to move freely.
Plant roots act as wedges that force rocks and soil particles apart.
Burrowing animals loosen rock and soil particles.

79. Mass Movement and Land Use
Section 4 Erosion and Deposition by Mass Movement
Chapter 10
Mass Movement and Land Use
Mass movement is one factor that must be considered during land use planning.
Officials must determine whether an area is safe for certain uses.
If poor choices are made, lives may be lost and property damaged.

80. Mass Movement and Land Use, continued
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Mass Movement and Land Use, continued
The effects of major mass movement events are usually unfavorable in the short term.
Long-term effects, however, may be beneficial.
For example, landslides may bring fresh minerals to the surface, which can form rich new soil.

81. Chapter 10
Agents of Erosion and Deposition
Concept Map
Use the terms below to complete the concept map on the next slide.
landslide
mass movement
angle of repose
rock fall
gravity
mudflow
creep

82. Chapter 10
Agents of Erosion and Deposition
Concept Map

83. Chapter 10
Agents of Erosion and Deposition
Concept Map