1. Weathering and Erosion
Investigation 1
November 3, 2015

2. Weathering
The process by which natural forces breakdown the materials of Earth’s crust into smaller pieces.

3. Physical Weathering
Process by which rocks are broken down into smaller pieces by external conditions.
Types of Physical weathering
Frost heaving and Frost wedging
Plant roots
Friction and impact
Burrowing of animals
Temperature changes

4. Frost Wedging
Water freezes, land expands
Can break up huge boulders

5. Frost Heaving

6. Plant Roots

7. Friction and Repeated Impact
Water can wear down rocks on riverbeds and along shorelines
Abrasion is the process of wearing down by friction, the rubbing of one object or surface against another.

8. Burrowing of Animals

9. Temperature Changes

10. Chemical Weathering
The process that breaks down rock through chemical changes.
The agents of chemical weathering
Water/dissolving
Oxygen
Carbon dioxide
Living organisms
Acid rain

11. Water
Water weathers rock by dissolving it (ex. Salt)

12. Oxygen
Iron combines with oxygen in the presence of water in a processes called oxidation
The product of oxidation is rust

13. Carbon Dioxide
CO2 dissolves in rain water and creates carbonic acid (weak acid)
The slightly acidic water breaks down minerals in rocks.

14. Living Organisms
Lichens that grow on rocks produce weak acids that chemically weather rock

15. Acid Rain
Compounds from burning coal, oil and gas react chemically with water forming acids.
Acid rain causes very rapid chemical weathering

16. Karst Topography
A type of landscape in rainy regions where there is limestone near the surface, characterized by caves, sinkholes, and disappearing streams.
Created by chemical weathering of limestone

17. Erosion
The process by which water, ice, wind or gravity moves fragments of rock and soil.

18. Water Erosion
Rivers, streams, and runoff

19. Ice Erosion
Glaciers

20. Wind Erosion

21. Mass Movements Landslides, mudslides, slump and creep
landslide clip.mpeg