1. Why does Earth’s surface change?
Today in Science
Milestones Practice Question Changes to Earth’s Surface Notes Almost done with notes for the YEAR!!!
Standard
Essential Questions
I can identify surface features on Earth caused by constructive and destructive processes.
Why does Earth’s surface change?

3. Review… What are the layers of the Earth? Which layer do we live on?
Why can we not live on the other layers?
What are tectonic plates?
What causes earthquakes to happen?

4. Review What is a fault? How are volcanoes formed?
The islands of Hawaii are landforms created by __________________.
What are tsunamis? What causes them to occur?
What is a seismograph?

5. Continental Drift Theory
The process of the continents slowly moving around on the surface of Earth.
The surface of the Earth, including under the ocean, is made up of tectonic plates.
The plates are sections of the surface of Earth, and some plates move towards or away from each other. Plates can also slide past each other.

6. Evidence to support the theory

7. Trenches
Trenches can be found where faults are located under the ocean.
Much smaller trenches are also caused by erosion.
GLACIERS: very old sheets of ice the size of states that move along Earth’s surface, also create trenches as they slowly grind the surface.

8. Where are trenches found?

9. Ridges
Ridges are formed when tectonic plates collide and both push up. This creates hills and mountains.
Ridges and individual mountains are formed in areas where magma, or molten rock, from Earth’s core pushes up between or through tectonic plates.
Stone mountain may be one of these magma-created mountains.

10. How were these ridges formed?

11. Weathering
A slow destructive process where Earth’s materials such as rocks and soil are broken down into smaller parts.
Weathering can also break down roads, buildings, and other materials humans make.
Forces that cause weathering: wind, water, and ice (these forces also cause erosion).

12. Quiz! What are the three causes (agents) of weathering?
Water
Wind
Ice

13. Mechanical Weathering
The breaking of larger rocks into smaller pieces.
Small pieces of rock = sediment
Ice causes mechanical weathering when water gets into the cracks of rocks and freezes. When water turns to ice, it expands, or takes up more room. When this happens, rocks break apart.
Moving air and water can also cause mechanical weathering.
Blown sand or rushing water hits rocks, and the rocks get weaker over time and eventually crack or crumble.

14. Mechanical Weathering by Wind

15. Mechanical Weathering by Water

16. Mechanical Weathering by Ice

17. Mechanical Weathering
Plants can cause mechanical weathering by sprouting and growing in soil that has collected in the cracks of a rock. As the plant grows, the roots extend and spread the crack until the rock eventually breaks

18. Quiz! What is mechanical weathering?
What are some examples of mechanical weathering?

19. Chemical Weathering Water that contains acid can dissolve rocks.
This water can trickle through the ground and can dissolve some rocks far under the surface.
Caves are hollow spaces underground that are formed by chemical weathering.

20. Review
What is erosion?
What is deposition?

21. People, Critters, and Erosion
Believe it or not people and animals are constantly eroding the earth around them.
Often times it is just a little bit of dirt sliding off a walking path but other times it can lead to massive problems.
During the Great Depression in the 1930's poor farming techniques helped cause what was known as the Dustbowl.

22. Quiz!
How can people cause erosion?
How can animals cause erosion?

23. Quiz! What is chemical weathering?
What is an example of a landform that is created by chemical weathering?

24. Constructive vs. Destructive Processes
These forces build up Earth’s surface.
Caused by water, gravity, wind.
What are some examples?
These forces break down Earth’s surface.
What are some examples?
Can be slow or fast:
Slow and destructive: erosion
Fast and destructive: earthquakes

26. Quiz!
What is a constructive force?
What is a destructive force?

27. Constructive or Destructive?
Delta

28. Constructive or Destructive?
People breaking soil to plant crops.

29. Constructive or Destructive?

30. Constructive or Destructive?
Sand Dunes

31. Constructive or Destructive?

32. Constructive or Destructive?
Animals digging up soil and causing erosion

33. Constructive or Destructive?
Formation of the Grand Canyon

34. Constructive or Destructive?
Earthquakes

35. Constructive or Destructive?
Weathering by wind
Arches

36. Constructive or Destructive?
Volcanoes

37. WED – create a diagram