S6E5. Students will investigate the scientific view of how the earth’s surface is formed. Gathering facts over erosion, weathering & deposition

1. Weathering
Types
Weathering
And
And
Erosion
Erosion
&
Deposition

2. Breaking it Down the Real Earth surface!
How does Erosion and Deposition Change the
Surface of the Earth?
S6E5. Students will investigate the scientific view
of how the earth’s surface is formed.
i. Explain the effects of human activity on the
erosion of the earth’s surface.
S6CS10. Students will enhance reading in all curriculum areas by:
c. Building vocabulary knowledge
Demonstrate an understanding of contextual vocabulary in various subjects.
Use content vocabulary in writing and speaking.
Explore understanding of new words found in subject area texts.
Essential Question(s): How does water and wind
change the surface of the earth?

3. Weathering
• Weathering is simply the chemical and/or
physical breakdown of a rock material--
weathering involves specific processes acting
on rock materials at or near the surface of the
Earth

4. The Different Types of
There are many different types of Physical /
Weathering
mechanical weathering .
Here are a few AGENTS:
•Root Pry
• Wind Abrasion
• Exfoliation
• Frost action
• Frost Action

5. Root plant action
Pry
The tree is growing in the
rock and soon the rock
will break apart because
of the tree roots.

6. This is a picture of
the Half Dome.
The rock is
peeling away from
the mountain in
layers just like an
onion. This is
exfoliation.

7. Frost Action or ice wedging slowly breaks up this
sedimentary rock into unusual shapes.

8. These rocks have been blasted by wind and
sand causing them to become rounded.
WIND ABRASION

9. Chemical weathering
and AGENTS:
Living Organisms
• Acids in Groundwater
• Karst Topography

10. This rock is red because of the oxidation of
iron in the sediment when the rock was
being formed.

11. 1908 to 1969
Acid rain has eaten away this limestone statue.
Acid Rain

12. Karst Topography
• A type of landscape in rainy regions where
there is limestone near the surface,
characterized by caves, sinkholes, and
disappearing streams.
• Created by chemical weathering of
limestone

13. Features of Karst: Sinkholes

14. Features of Karst: Caves

15. Living Organisms
• Lichens that grow on rocks produce weak
acids that chemically weather rock

16. Chemical
Weathering

17. There are 4 factors that affect the rate of weathering:
1. Surface Area (exposure) - Exposing more surface area will
increase the rate of weathering.
2. Particle Size – Larger particles weather slower and smaller
particles weather at a faster rate.
3. Chemical Composition (what a rock is made of) – Certain rocks
and minerals are naturally weaker than others, while others are
more resistant (stronger).
4. Climate – Warmer, moister climates have the most weathering.
Heat & Water speed up all chemical reactions. This is the most
important factor in weathering. 17

18. Erosion is the process by which
soil and rock are moved from
one location to another on the
surface by natural processes
such as wind or water flow, and
then transported and deposited
in other locations.

19. Erosion
There are many kinds of Erosion.
Here are a few AGENTS:
• Wave Action • Avalanche •Creep
• Running Water •Glaciers • Rock Fall
• Landslides • Slump • Mud Flow

20. What is Erosion?
 Erosion is defined as removal of
rocks and soil by wind, water, ice and
gravity.
 Wind, water, ice and gravity are also
known as the agents of erosion and
through erosion, a river creates
valleys, waterfalls, flood plains,
meanders, and oxbow lakes

21. Water Erosion
 Water running downhill is the major agent
of erosion that has shaped Earth's land
surface. The force of a falling raindrop
can loosen and pick up soil particles. As
water moves over land, it carries these
particles with it. This moving water is
called runoff, which is water that moves
over Earth's surface.

22. Wave action is when waves hit the rocks
and pieces of rock break off.

23. In this picture the running water eroded the sides
of this canyon and created the V-shaped valleys.

24. Gravity Erosion-Rock Fall
Gravity Erosion is better known as Mass Movement
and is defined as the transfer of rock and soil down
slope by direct action of gravity without a flowing
medium (such as water or ice). Some of the best
examples of Mass Movement are:
Creep
Rock fall Slump

25. Mass Movements
• Landslides, mudslides, slump and creep
Slower Faster
landslide clip.mpeg

26. This is a picture of a landslide.
A type of mass wasting.

27. In this picture the land has slumped
into the road below.

28. This is a diagram of creep. The hillside
slowly slips over many years from
temperature or water.

29. This is a picture of an avalanche. It
is similar to a landslide with ice
and snow instead of rock.

30. LANDSLIDE MUDFLOW
1 2
What type of mass movement is each picture?
http://classes.colgate.edu/dkeller/geol101/massw/mass.htm
SLUMP CREEP
3 4

31. Ice Erosion
Glaciers wear down the landscape; by picking up
and carrying debris that moves across the land
along with the ice.
Glaciers can pick up and carry sediment that
ranges in size from sand grains to boulders bigger
than houses.
Moving like a conveyor belt or a bulldozer, a single
glacier can move millions of tons of material!
How much erosion takes place is determined by
the:
•**Sum (Glaciers are massive!)
•Slope
•Speed

32. Ice
Ice (glaciers) carry sediment.

33. This is a picture of a glacier which carves
out a U-shaped valley where it flows
dragging rocks and boulders along the way.

34. You can identify which agent of erosion transported each sediment by looking at
a few characteristics:
Running Water – sediments that have been transported through
running water appear rounded and smooth and are deposited in
sorted piles.
Glaciers – sediments that have been transported by glaciers appear
scratched, grooved, and are deposited in completely unsorted
piles, because they were dropped during melting. Also, boulders
can only be transported by glaciers.
Wind - sediments that have been transported by wind are appear
pitted (random holes) and frosted (glazed look) and are deposited
in sorted piles. Only very small particles can be transported by
wind.
Gravity – sediments that are transported by gravity are found in
piles at the bottom of cliffs or steep slopes. They appear angular
and unsorted. Mrs. Degl 34

35. Factors that influence erosional rates (speed) in running
water and glacial ice:
1. Slope (gradient) of the land – as slope increases, the
water velocity increases, the particle size that the water
can carry also increases, therefore the amount of erosion
increases.
2. Volume (size of the water or glacier) – as the volume of
the water or glacier increases, their velocities increase,
the particle size that they can carry also increases,
therefore the amount of erosion increases.
3. Position within the running water – Water is traveling
faster around the outside of turns therefore that is
where more erosion occurs. Water is traveling slower on
the inside of turns; therefore deposition occurs on the
inside. Mrs. Degl 35

36. Deposition
Rock particles that are picked up and transported
during erosion will ultimately be deposited
somewhere else
Deposition is the process by which sediments (small
particles of rock) are laid down in new locations.
• Together, Erosion and Deposition build new
landforms.
• Deltas
• Canyons
• Meanders
• Floodplains

37. Water Deposition
 Deltas – slow river current drops sediment in fan-shaped
pattern at end of river
 Sand Bars – offshore deposit of sand, gravel, or shell
material
 Alluvial Fans
 Beaches – deposited sand

38. Delta
• Where rivers meet the
ocean is called the
mouth of the river.
Soil and dirt carried
by these rivers is
deposited at the
mouth, and new land
is formed. The new,
soil-rich land is known
as a Delta

39. Delta – a fan shaped deposit that forms at the mouth of a
river/stream when it enters a larger body of water. This is seen
under the water. The particles are horizontally sorted.
Mrs. Degl 39

40. Alluvial Fan - a fan shaped deposit of sediments that forms
when a stream/river flows out of a mountain on to flat, dry plains.
These are not under water and are very visible. This only
happens on the land. You can call it a “land delta”.
Mrs. Degl 40

41. Canyons
Canyons are large valleys
created by a river or stream.

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

43. Meandering (Curving) River/Stream
Deposition
Erosion
happens
happens
on the
on the
inside of
outside of
turns.
turns.
Sediments
are Straight Flowing River/Stream Running
traveling
the fastest Water
in the
center
directly
below the
surface. Mrs. Degl 43

44. Mrs. Degl 44

45. Floodplains
• These are low-
lying areas along
the sides of a river
channel that have
regular times of
heavy wate rflow
to cause the river
to spill over and
flood the land.

46. http://www.school-portal.co.uk/GroupDownloadFile.asp?file=21604
5
1 2 3
2 SANDBAR
DELTA BEACH
1
4 4 6
4
ALLUVIAL FAN
What did water create in each of these pictures?

47. Humans are
How does this affect us? constantly
influencing the
nature of our
landscapes.
HOUSES, ROADS,
BUILDINGS,
DEVELOPMENTS,
CANALS, etc., all
change the shape
and appearance of
the land.

48. There are 5 ways that man can cause erosion:
1. Forestry – all vegetation of removed,
and without roots, the soil will erode
away.
2. Strip Mining –removing rock cover to
get to the resources below, this causes the
loose sediments to erode away.
3. Construction – the clearing of land to
build buildings/houses also causes all
loose soil to erode away.
4. Improper Farming – not plowing the
land at right angles to slopes causes soil
to erode away.
5. Salting Highways – the salt is washed
off the road to the sides, where it
prevents vegetative growth along the 48
sides.

49. Summary please pick ONE
• Use at least two facts from your notes
to explain the question below.
• How does Erosion and Deposition
Change the Surface of the Earth?
OR
• How does water and wind change the
surface of the earth?
49