1. Construction and Destruction of the Earth

2. Construction and Destruction of the Earth
Some forces of nature are constructive – they build up the Earth
Can you think of some constructive forces?
Other forces are destructive – they wear down the Earth
Can you think of destructive forces?

3. The earth is made up of many plates that make up the Earth’s crust

4. Earthquakes Are they constructive or destructive?
During an earthquake some crust may push other crust around depositing it somewhere else – building crust in another area
During an earthquake some crust may be destroyed – let’s model it

5. Earthquakes
During an earthquake some crust may be destroyed – let’s model it
Give each student an Oreo cookie
Tell students to separate the two halves of the cookie and scrape their teeth over the filling
This is like the plates of the earth’s crust scraping & moving past each other
Ask students what happened to the white filling “crust”
So earthquake can be: constructive or destructive?

6. Volcanoes Let’s model a volcanic eruption
Give each student a volcano model made from “Plaster of Paris” - you need to make these ahead of time
Give each student a Ziplock bag of powered “Plaster of Paris”
Add some water & mix with “Plaster of Paris”
Use scissors to cut the corner of the bag and have students “erupt” the mixture onto their volcano model

7. Volcanoes Your model eruption is similar to a real eruption because …
Your Plaster of Paris “lava” cools and hardens just like real lava
Did this construct or build new crust or destruct it? – circle one

8. Glaciers Glaciers are a large slow moving river of ice and debris
Let’s model how glacier’s effect the earth’s surface

9. Glaciers Did your glacier make any marks on your volcano?
Your model glacier is similar to a real one because the real glacier also has rocks that scrape the land when the glacier moves over the land
Did this construct or build new crust or destruct it?
It also pushes soil, boulders, and other things in its path out of the way and deposits them somewhere else
Does this construct or build new crust or destruct it?
This is a picture of a real U-shaped valley

10. Let’s try some sample TAKS questions.

11. This does NOT build new land
Lava cools & hardens to build new land
This does NOT build new land

12. The glacier does not directly affect this.
The glacier carves the shape of the valley