Weathering, Erosion & Deposition power point for my students.

1. By Jeanie Lacob 2014

2. Landslides
Gravity causes
Erosion
How much erosion takes
place is determined by
the:
• **Slope
• Speed
• **Surface

3. Erosion
Erosion is the
of rock material
(sediment) from
one
to another.
What do you think has caused
this rock to look this way?
__________
______
Erosion carves the Earth's surface
creating canyons, gorges, and
even beaches.

4. Erosion
Erosion is the
of rock material
(sediment) from
one
to another.
What do you think has caused
this rock to look this way?
movement
place
Erosion carves the Earth's surface
creating canyons, gorges, and
even beaches.

5. The process by which water, ice, wind or
gravity moves fragments of rock
and soil is called?
_____________

6. The process by which water, ice, wind or
gravity moves fragments of rock
and soil is called?.
Erosion

7. Gravity causes erosion
Creep, Slump, Landslides, Mudslides, and Avalanches.
Slower Faster
These are examples of mass movement
landslide clip.mpeg
(or called mass wasting)

8. Landslide
landslide clip.mpeg
Landslide – the sudden
movement of loose rock
and soil down a steep
slope

9. Mudslide
mudslide – caused by:
Heavy rain or sudden melting of snow (for example as a
result of a volcanic eruption)
Wet or dry
conditions?
wet

10. Rockslide
rockslide –
caused by:
Loosened rocks
suddenly falling
from cliffs
Wet or dry
conditions?
DRY

11. Landslide
• Landslide time lapse
slower
faster

12. Weathering and Erosion

13. True or False: The Earth’s surface
has stayed the same for thousands of
years

14. True or False: The Earth’s surface
has stayed the same for thousands of
years
The Earth’s surface is always
changing!

21. Weathering
Is the process in which rocks are
worn away into smaller pieces

22. Erosion
Erosion is the
of rock material
(sediment) from
one
to another.
What do you think has caused
this rock to look this way?
movement
place
Erosion carves the Earth's surface
creating canyons, gorges, and
even beaches.

23. Wind Erosion
• As the wind
blows it picks
up small
particles of
sand/sedime
nt and blasts
large rocks
with the
abrasive
particles,
cutting and
shaping the
rock.

24. Wind Erosion

25. Water Causes Erosion
• runoff, rivers and, streams

26. The power of water
. Water is the
primary (#1)
agent of
weathering
and erosion
on Earth.

27. Water causes Erosion
How much erosion
takes place is
determined by the:
• Sum (amount of)
• Slope
• Speed
• Surface

28. Freezing water causes
weathering
•
Describe how ice
causes weathering?
Water can
break rocks
apart when it
freezes and
e_x_p__a_n_d_s__.
Animation of ice wedging

29. Ice causes weathering
The expanding ice makes
the cracks bigger.
Over time, periods of
freezing and melting cause
the rocks to break.

30. Wind causes weathering
Why wasn’t this mass
of land weathered
away?
What evidence of
weathering do you see
in this picture?

31. Plants CAN CAUSE weathering
Main idea page 83 Section C “I. B”
Growing roots widen cracks and
the rock breaks.

32. Plants CAN PREVENT erosion

33. Other ways to PREVENT erosion
A windbreak (the row of trees)
planted next to a field, acts as a
shield against strong winds,
reducing wind erosion.
Terracing of a hillside slows the
rate of water erosion on cultivated
slopes.

34. Heating and cooling can cause
weathering
Main idea page 83 Section C “I. D” and “E”
Outer layers of rock can
peel off when a forest
fire or the Sun heats up
the outside of a rock.
When cool rainwater falls on
heated rocks , it can cause them
to break.

35. Chemicals can weather rocks
Gases in the air react
with iron in some rocks
to form rust, which
crumbles.
Acid rain weakens
rock, causing it to break
apart.
Main idea page 83 Section C “I. F”

36. Glacier
Glaciers
• A glacier is a large
• mass of _________-
slow
• moving ________.
ice

37. Ice Causes Erosion
Glaciers wear down the
landscape; by picking up and
carrying debris that moves
across the land along with
the ice.

38. Ice Causes Erosion
Glaciers can pick up and carry sediment that ranges in size
from sand grains to boulders bigger than houses.
Glacier Bay,
Alaska
Moving like a conveyor belt and a bulldozer, a single
glacier can move millions of tons of material!

39. http://www.geocaching.com
A single large boulder
moved by a glacier
from one place and
deposited somewhere
else when the glacier
melts is called?

40. Daggett Rock –
Maine's Largest
Glacial Erratic
http://www.maine.gov
deposited by the Mendenhall
Glacier, seen in the background.
Juneau Icefield, Alaska

41. A long ridge formed by boulders,
rocks, and soil carried and
deposited by a glacier
http://www.isgs.uiuc.edu

42. What is the long ridge formed by
boulders, rocks, and soil carried
and deposited by a glacier called?

43. Ice Causes Erosion

44. Grand Canyon
Rivers produce what shaped valleys?

46. Canyons
This simple animation provides
you with a visualization of how the
Colorado River has "downcut"
into the rock layers of the Grand
Canyon.
How long it took to carve the
Grand Canyon is debated by
geologists.
Some estimates are between
6 and 8 million years, which is
very recent Canyons are large by geologic time.
valleys created by a
river or stream.

47. Damage from Dust Storm in Oklahoma, 1936: In the 1930s, agricultural
damage, coupled with drought and windstorms, resulted in the severe
damage and destruction across the Plains states that became known as the
Dust Bowl. (Photo Credit: CORBIS)

48. Dust storms crackled with powerful
static electricity.So much static electricity
built up between the ground and airborne
dust that blue flames leapt from barbed
wire fences and well-wishers shaking
hands could generate a spark so powerful
it could knock them to the ground. Since
static electricity could short out engines
and car radios, motorists driving through
dust storms dragged chains from the back
of their automobiles to ground their cars.

49. Chapter 7 Lesson 2: Deposition
• Erosion and Deposition can build new landforms
such as : headlands and deltas

50. Deposition
Deposition is the process by which
sediments (small particles of rock)
are _p_u_t__ down in new locations.

51. Headland
point
Headland – a _______of land, usually
high, that extends into the _______
water

52. Delta
Deltas have a
shallow slope,
contain _____
grained sediment
(sand and mud)
Flow into a body of
__________
(generally).
Nile River Delta
fine
water

53. Deltas vs. alluvial fans:
• Deltas have a
• shallow slope,
• contain fine-grained
sediment (sand and mud)
• flow into a body of water
(generally).
• Alluvial fans have large
• coarse-grained sediments
(including boulders),
• dominated by debris flows and
large floods; these floods are
often flash floods.
• Can flow onto a land surface, or
into a body of water
Delta or alluvial fan?

54. Meanders
Meandering streams wander side to side as they
constantly seek out the lowest elevation.
This constant motion creates a series of S-shaped
“loops”.

55. Meanders
Stream Velocity varies from one side to the other side
of the “S”, resulting in erosion in some places and
deposition of sediments in others.

56. Meander
formation
Meander
formation
Fast-moving water erodes the
outer edge of the curve, cutting
the river bank.
Slow-moving water deposits the
sediment on the inner edge of
the curve, forming a sandbar.

57. Because _____________ water
deposits the sediment on the
_________ edge of the curve,
forming a sandbar.
Why is the sand being
deposited here?
slow-moving
inner
Fast-moving
Slow- moving
Inner
Outer

58. • Animation of evolution of a
meandering stream
• Lab Activity

59. Flood plains
• low-lying areas along the sides of a river that during
regular times of heavy water flow can be flooded by spill
over from the river.

60. How does water shape the land?
Moving water changes Earth’s surface through:
• ___________ Weathering
- the process in which rocks are worn
away into smaller pieces
Erosion
• _________ - the movement of rock material (sediment)
from one place to another.
Deposition
• ____________ – the process by which sediments
(small particles of rock) are put down in new
locations

61. River System
The Missouri/ Mississippi River System is the largest
river system in the United States.
streams
small rivers
medium rivers
Larger rivers

62. River System
Major US Rivers (in order by length):
River, Length in miles (flows into)
1. Missouri, 2,540 miles (flows into Mississippi River)
2. Mississippi, 2,340 miles (flows into Gulf of Mexico)
3. Yukon, 1,980 miles (flows into Bering Sea)
4. Rio Grande, 1,900 miles (flows into Gulf of Mexico)
4. St. Lawrence, 1,900 miles (flows into Gulf of St. Lawrence)
6. Arkansas, 1,460 miles (flows into Mississippi River)
7. Colorado, 1,450 miles (flows into Gulf of California)
What are the 2 longest rivers in the United States?
Missouri Mississippi

63. How can people change a
River System?
Effects of the dam:
1.Flood control
2. Water can be used
to make electricity
By pushing turbines
as it flows through
the dam
3. Provides recreation
Hoover Dam near Las Vegas, Nevada
Building dams across the river

64. Where do you think the sediment carried by
this river is being deposited?
Behind the dam

65. What does the Mississippi River System
form when it flows into the ocean?
An alluvial fan or a delta?
DELTA

66. bay
A body of water that is partly enclosed by land and has
a wide opening.

67. How does wind action effect our beaches?
The wind can pile up sand
into a sand dune

68. How does wave action effect our beaches?
Seasonal change is illustrated in
two postcards that depict the
same Santa Barbara beach
during summer and winter
conditions in 1909 and 1910.
summer
winter

69. During summer, the waves are milder and deposit sand
on the beach

70. During winter, waves are stronger and erode sand off the
beach, storing it in offshore sandbars

71. Wave action causes the sand to be moved along the beach
Click here for Animation of sand drift along beaches

73. This picture shows a hillside covered with gullies
due to ________ caused by rainfall
A. Deposition B. erosion C. glacier action