Weathering and Erosion

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Weathering and Erosion
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Weathering

• The breakdown of Earths crust into smaller
  pieces.

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Mechanical (Physical) Weathering

• Process by which rocks are broken down into
  smaller pieces by external conditions.
• Types of Mechanical weathering
• Frost heaving and Frost wedging
• Plant roots
• Impact of wind and water
• Abrasion
• Burrowing of animals
• Temperature changes

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Frost Wedging
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Frost Heaving
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Plant Roots
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Friction and Repeated Impact
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Burrowing of Animals
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Temperature Changes
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Chemical Weathering

• The process that breaks down rock through
  chemical changes.
• The agents of chemical weathering
• Water
• Oxygen
• Living organisms
• Acid Rain
• Carbon Dioxide

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Water

• Water weathers rock by dissolving it

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Oxygen

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

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Living Organisms

• Lichens that grow on rocks produce weak acids
  that chemically weather rock

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Acid Rain

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

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Carbon Dioxide

• CO2 dissolves in rain water and creates carbonic
  acid
• Carbonic acid easily weathers limestone and marble

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Karst Topography

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

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Features of Karst Sinkholes
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Features of Karst Caves
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Features of Karst Disappearing Streams
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Erosion

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

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Water Erosion

• Rivers, streams, and runoff

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Ice Erosion

• Glaciers

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Wind Erosion
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Mass Movements

• Landslides, mudslides, slump and creep

landslide clip.mpeg
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What have you learned?

• What is erosion?
• 2. How are weathering and erosion connected?
• Give 2 examples of weathering.
• 3.
• 4.
• Give 2 examples of erosion.
• 5.
• 6.