1. Today’s Agenda…1/20 
Bellringer: How do weathering and erosion change the surface of the Earth?
Turn in worksheets
Notes on Constructive and Destructive Forces
Before/After Landscape Assignment

2. Weathering What is weathering? What are the two types of weathering?
Give an example of mechanical weathering.
Give an examples of chemical weathering.

3. Erosion
What is erosion?
What are the agents of erosion?

4. Forces That Shape Our Earth
Study Pack #10

5. Today’s Goals… I can describe constructive and destructive forces
I can identify examples of constructive and destructive forces

6. Think about it! 
How is the surface of the Earth changing everyday?

7. Forces
The surface of the Earth is constantly changed by constructive and destructive forces

8. Constructive Forces Build up the Earth’s surface
Types of constructive forces:
Crustal deformation
Volcanic eruptions
Deposition of sediment

9. Crustal Deformation
The movement of plates builds landforms such as volcanoes and mountains

10. Volcanic Eruptions
As lava erupts onto the Earth’s surface it cools to form new layers of rock which build up the Earth’s surface

11. Deposition of Sediments
As sediments are carried away and laid down they build up landforms
This is called deposition
Example: Sand dunes, deltas, sandbars

12. Destructive Forces Wear down Earth’s surface
Types of destructive forces:
Weathering
Erosion

13. Erosion Changes Earth’s Surface
Rock and sediments are moved from one place to another
Where material is removed, canyons and valleys form

14. Homework…
You are going to draw a before and after picture of a landscape
At least one constructive OR destructive force will cause a change in your landscape over time
The before picture shows what the landscape first looked like
The after picture shows what it looked like after the constructive or destructive force changed it

15. Homework…
Write 1 paragraph to explain what happened to your landscape over time and what caused it to change
You will want to include terms such as: constructive force, destructive force, erosion, weathering, volcanic eruptions, deposition, crustal deformation, plate movement