1. Changing
Landforms
3.7B; 4.7B; 5.7B

2. True or False: The Earth’s surface has stayed the same for thousands of years.
Think about the statement in the box above. Do you think it is a true statement or a false statement?

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

4. Changing
Landforms
Let’s look at a large rock by the seaside over a period of years.
1890
1910
The rock changed over this 80 year period. In fact, it almost disappeared!
1920
1970

5. Changing
Landforms
What do you think caused these drastic changes in the rock?
What could possibly make rock break down into smaller pieces?
1890
1970

6. Weathering and Erosion
Wind
Water
Ice
Gravity

7. Weathering leads to the formation of new soil.
The breakdown of the materials in the Earth’s crust into smaller pieces.
Weathering leads to the formation of new soil.

8. Moving water can cause weathering.
What evidence of weathering do you see in this picture?

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

10. Ice can cause weathering.
Water can get into cracks in rocks. If the water freezes, it can push the sides of the crack farther apart, making the crack larger and larger.

11. Plants CAN CAUSE weathering

12. What evidence of erosion do you see in this picture?
The process by which water, ice, wind or gravity moves fragments of rock and soil.
What evidence of erosion do you see in this picture?

13. Erosion is the movement of sediments!
Erosion gradually wears down the surface of the earth.
Erosion carves the Earth's surface creating canyons, gorges, and even beaches.
Erosion is the process by which weathered rock and soil (sediments) are moved  from one place to another.
What do you think has caused this rock to look this way?

14. The intensity of wind erosion is determined by:
As the wind blows it picks up small particles of sand/sediment and blasts large rocks with the abrasive particles, cutting and shaping the rock.
The intensity of wind erosion is determined by:
The amount of wind
The speed of the wind
The slope of the land
The surface of the land

15. Evidence of Wind Erosion
Creates sand dunes
Greatest impact
in deserts
Removes
fertile topsoil

16. Moving water causes erosion!
Creates MOST of the changes
in the Earth's landscape!

17. Moving water causes erosion.
When rain falls to the Earth it can evaporate, sink into the ground, or flow over the land as Runoff.
When it flows over land, erosion occurs.
Runoff picks up pieces of rock and "runs" downhill cutting tiny grooves (called rills) into the land.
Rivers and streams are a
constant flow of runoff-
they constantly weather and erode!

18. Moving water causes erosion.
How much erosion takes place is determined by the:
Amount of water
Slope of the land
Speed of the water
Surface of the land

19. Moving ice causes erosion.
Glaciers wear down the landscape by picking up and carrying debris that moves across the land along with the ice.

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

21. Moving ice causes erosion.
How much erosion takes place is determined by the:
Size of the glacier
Slope of the land
Speed of the glacier
Surface of the land

22. Gravity causes erosion
Landslides and Avalanches.
Slower
Faster
These are examples of mass movement
(also called landslides)

23. Gravity causes Erosion
How much erosion takes place is determined by the:
Amount of falling debris
Slope of the land
Speed of the falling debris
Surface of the land

24. Plants CAN PREVENT erosion

25. Together, Erosion and Deposition build new landforms.
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
Sand dunes
Hills

26. Deposition and erosion together form deltas.
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

27. Weathering and erosion together form 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 by comparison.
Canyons are large valleys created by a river or stream.

28. Erosion and deposition together form sand dunes.
Wind can move erode and deposit sediments, especially when it blows across open areas with no vegetation.
Wind tears down landforms when it erodes sediments.
Wind builds up landforms when it deposits sediments.
Sand dunes are hills of sand deposited by the wind.

29. What are landforms?
The natural shapes or features on the Earth’s surface are called landforms.
Many different types of landforms can be found on the Earth.

30. canyon
A canyon is a deep valley with very steep sides. Rivers often flow through canyons.

31. coastline
A coastline is the area where the ocean touches the land.

32. delta
A delta is a large, flat area of land where a river flows into an ocean or sea.

33. hill
A hill is a rounded area of land higher than the area around it (not as high as a mountain).

34. island
An island is land that is completely surrounded by water.

35. mountain
A mountain is a place on Earth’s surface that is much higher than the land around it.

36. sand dune
A sand dune is a hill of sand that is deposited by the wind.

37. valley
A valley is a long, low area of land that is surrounded by higher land.

38. What’s the evidence???
What natural processes led to the formation of this landform? What evidence can you give for this conclusion?

39. What’s the evidence???
What natural processes led to the exposure of these tree roots? What evidence can you give for this conclusion?

40. What’s the evidence???
What natural processes led to the formation of this landform? What evidence can you give for this conclusion?

41. What’s the evidence???
What natural processes led to the formation of this landform? What evidence can you give for this conclusion?

42. What’s the evidence???
What natural processes led to the formation of this landform? What evidence can you give for this conclusion?

43. What’s the evidence???
What natural processes led to the formation of this landform? What evidence can you give for this conclusion?

44. What’s the evidence???
What natural processes led to the formation of this landform? What evidence can you give for this conclusion?

45. What’s the evidence???
What natural processes led to the formation of these cracks in the ground? What evidence can you give for this conclusion?

46. What’s the evidence???
What natural processes led to the formation of this landform? What evidence can you give for this conclusion?

47. What’s the evidence???
What natural processes led to the formation of these cracks in the ground? What evidence can you give for this conclusion?

48. What’s the evidence???
What natural processes led to the formation of this landform? What evidence can you give for this conclusion?

49. What’s the evidence???
What natural processes led to the formation of this island? What evidence can you give for this conclusion?
Notice the evidence of the delta where the river flows into the sea.

50. What’s the evidence???
What natural processes led to the destruction of this landform? What evidence can you give for this conclusion?