1. Earth’s Changing Surface
presented by Robbie Higdon
Winter/Spring 2003
Adventure of the American Mind project

2. Earth’s Changing Surface
The earth’s surface is built up by constructive forces
The earth’s surface is torn down by destructive forces

3. Constructive Forces Deposition of sediments Creation of soils
Used by permission from Library of Congress/American Memory Collection

4. Destructive Forces Weathering—the process that breaks down rock
Erosion—movement of weathered rock and soil from one place to another
Used by permission from the Library of Congress/American Memory Collection

5. Effect on Humans
Natural forces have had an effect on how humans interact with the Earth’s surface…
Which, in turn, have led to the conservation and destruction of the environment

6. What is Conservation?
Using resources from the environment as long as those resources are not being destroyed
Managing the Earth’s resources for the future, not just for today

7. Used by permission from Library of Congress/American Memory Collection

8. “Tradition of Waste”
Beginning in the mid to late 19th century, natural resources were being heavily exploited
Clear cutting of forests
Overgrazing
Improper mining practices
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9. Early Conservationists
Two early figures in the conservation movement—
John Muir founded the Sierra Club in 1892
President Theodore Roosevelt established the first National Wildlife Refuge in 1903
Used by permission of the Library of Congress/American Memory Collection

10. Today’s Environmental Issues
Overuse of resources
Human population growth
Pollution of the soil, air, and water
Loss of habitat and species
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