1. Erosion Song
EROSION

2. EROSION: Erosion is the transport of sediments around the earth
Erosion is driven by the force of gravity.

4. THE AGENTS OF EROSION ARE:
RUNNING WATER
MOVING ICE (GLACIERS)
GRAVITY (Mass Movements)
WIND

5. What is the The primary agent of erosion?
RUNNING WATER

6. Colorado River

8. Grand Canyon

9. Niagara Falls

13. Agents Erosion
Each agent of erosion produces its own characteristic shape and texture in the sediment.

14. Erosion by water makes
The rock get ROUND and SMOOTH,

15. EROSION BY WATER:
PARTICLES ARE CARRIED IN SEVERAL WAYS DEPENDING ON THEIR
SIZE

16. How do streams transport sediment:

17. SEDIMENTS that can dissolve are transported IN SOLUTION:
Examples:
Salt
Calcite

18. Dissolved ions in solution
Merrill Snyder

19. Small SEDIMENTS are transported IN SUSPENSION
Examples:
SILT
CLAY

20. Merrill ES Snyder Feather Hesser

21. Large Sediments dragged along the bottom:
Large Sediments dragged along the bottom

22. What determines how large a sediment a stream can erode?
Merrill Snyder

23. What does the velocity (speed) of the stream depend upon?

24. VELOCITY OF A STREAM DEPENDS ON:
SLOPE (gradient) AND
DISCHARGE (volume of water)

25. Where does a stream flow the fastest on straight path
Where does a stream flow the fastest on straight path? (middle, sides, top or bottom)
Top View
Side of Stream
(Stream Bank)
Top of Stream
Bottom of Stream
Side View
The forces of friction, cohesion and drag all play a role in the streams velocity.
Stream velocity is highest in the middle and top.

26. velocity center surface B Maximum erosion occurs where there
is maximum
_____________
On a straight path
the maximum velocity
is in the ___________
below the ____________
velocity C D
center E F
surface

27. When rivers enter a large body of water their velocity decreases and deposition occurs (depositing of sediments) How are the sediments deposited?
Nissequogue enters the
Long Island Sound

28. SEDIMENTS LEFT BEHIND BY STREAMS ARE ________
SORTED
dropped off in size order

29. SORTING

30. What is the relationship between particle size and water velocity?
(SEE REF. TABLE PAGE 6)

31. Stream Velocity
The Relationship of Transported Sediments to Water Velocity:
When velocity of the stream increases the size of the particle eroded increases

32. CALCULATE THE MINIMUM VELOCITY OF A STREAM NEEDED TO CARRY A PEBBLE (1 cm in size):

33. (SEE REF. TABLE PAGE 6)

34. What effect does erosion and deposition have on the stream?
It causes the stream to go through stages
THE MOVEMENT
OF THE WATER
CAN EVENTUALLY
FORM AN
OXBOW LAKE

35. Young Stream

36. Mature Stream
Oxbow Lake

37. Old Age Stream

38. Comparing Young and Old Age Streams
Narrow V – shaped valley
Straight path
Steep slopes
Fast moving water
Waterfalls, rapids
Mature/Old Age
Wide valley
Many meanders
Low slope
Oxbow Lakes

39. Young Streams create V shape valleys

40. Old Stream

41. Why does a stream develop meanders?

42. outside of inside of (EROSION) (DEPOSITION) Water moves faster on the
a bend
(EROSION)
DEPOSITION
Water moves
slower
on the
inside of
a bend
(DEPOSITION)
EROSION

43. A B C D E

44. A B C D E

45. A B C D E

46. A B C D E

47. A B C D E

48. A B C D E

49. A B C D E

50. A B C D E

51. A B C D E

52. A B C D E

53. A B C D E

54. WHY DID RUBBER DUCKY “C” WIN THE RACE?

55. WHY WOULD THE WATER MOVE FASTER IN THE MIDDLE AND SLOWER NEAR THE SIDES?B C D E

57. WHICH RUBBER
DUCKY IS GOING
TO WIN? A B C D E
START
FINISH

58. A B C D E
START
FINISH

59. A B C D E
START
FINISH

60. A D E B C
START
FINISH

61. START E D A C B
FINISH

62. START E D A C B
FINISH

63. START E D C A B
FINISH

64. START E D C A
FINISH B

65. WHY DID RUBBER
DUCKY “B” WIN
THE RACE?
START E D C
FINISH A B

66. WHAT WOULD A CROSS SECTION (SIDE-VIEW) OF THE STREAM LOOK LIKE AT THE FINISH LINE?
AERIAL VIEW
(A) (B) (C) (D)
CROSS-SECTION (SIDE VIEW)

67. What factors affect deposition rate in a river
What factors affect deposition rate in a river? Characteristics of the sediment animation
Size
Shape
Density

68. RATES OF DEPOSITION DEPEND ON:
smaller
1. Particle size: ________
particles (clay,silt) settle more slowly than larger particles.

69. 2. Particle shape:
friction
____________ between water and the surface of particles _______ settling.
As the surface area ___________ the time it takes to settle __________
The rounder the particle the faster ______ it will deposit.
slows
increases
increases

70. ____________ particles settle faster.
3. Particle Density:
____________ particles settle faster.
denser

71. What is the relationship between settling rate and particle size?
Complete the graphs:
label each axis
Settling
rate
Particle size Increase

72. What is the relationship between settling rate and shape?
Particle gets flatter

73. What is the relationship between settling rate and density?
Density increases

74. What is the relationship between Settling Rate and Settling Time?
As the settling time increases
The settling rate
settling
rate
Inverse Relationship
Settling time

75. Describe the size, shape and density of a particle that deposits quickly (greatest rate)
A particle that is large, round and dense.

76. The slower the velocity of the water the ________
How does the velocity of the transporting medium ( water, wind, ice) affect deposition?
The slower the velocity of the
water the ________
particles will settle.
It takes longer for particles to settle
in ___________ water.
FASTER
moving

77. What is horizontal sorting and when does it occur?
animation

78. Horizontal Sorting:
a gradual change in the size,shape and density
(of deposited particles)
when a stream enters a large body of water and slows down.

79. Horizontal Sorting stream evaporation Ocean Ions in solution ……………
boulders
cobbles
Roundest
and
densest
pebbles
sand
evaporation
Ocean
Precipitation
silt
……………
…………….
Ions in
solution
(colloids)
clay
Smallest
flattest
least dense

80. Draw this diagram of horizontal sorting.

81. What is a delta and how does it form?
A delta is forming where the Nissequogue River meets the Longs Island Sound.

82. Mississippi River Delta

83. Nile River Delta

84. Delta is a triangle shape feature that forms at the mouth of the river where sediment is deposited

85. What is vertical sorting?
Animation

86. Vertical Sorting Sorting of particles from bottom to top in a layer.
Occurs during flood events or when a landslide
falls into a body of water
Small
Flat
Low density
Large
Round
Dense

87. What is graded bedding and when does it occur? animation
Series of vertical sorting happen over and over again.
Occurs when Landslides happen over and over again. Also when flooding occurs

88. Graded Bedding: Each layer represents a single event of deposition
(3 floods)