GEOG 1113: Landform Geography

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GEOG 1113 Landform Geography February 12,
2015 Weathering Mass Wasting Events

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Weathering

• Process by which rocks break down into smaller
  pieces
• Two Primary Types
• Mechanical (or physical) cold, dry environments
• Chemical warm, moist environments

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Mechanical Weathering

• Destruction of rock through physical stresses
• Rocks break into small pieces surface area of
  rock increases even greater weathering
• Types
• Frost Wedging
• Impact of Roots
• Temperature Fluctuations
• Salt Crystal Growth
• Exfoliation

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Frost Wedging
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Impact of Roots
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Temperature Fluctuations
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Salt Crystal Growth
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Exfoliation
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Chemical Weathering

• Changes rock by altering its chemical composition
  water particularly important
• Types
• Hydrolysis
• Oxidation
• Carbonation
• Acid Rain

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Hydrolysis
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Oxidation
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Carbonation
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Acid Rain

• Coal-burning power plants in Midwest emit sulfur
  dioxide (SO2) nitrogen oxides (NOx)
• SO2 NOx mix with water in clouds to form
  sulfuric or nitric acid
• Clouds move east where acid rain falls
• Acid rain accelerates chemical weathering
• Acid rain can also harm lakes forests
• Regulation has cut acid emissions dramatically

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Effects of Acid Rain

• The ecological effects of acid rain are most
  clearly seen in the aquatic, or water,
  environments, such as streams, lakes, and
  marshes.
• Most lakes and streams have a pH between 6 and 8,
  although some lakes are naturally acidic even
  without the effects of acid rain.
• Buffering capacity
• Nitrogen is an important factor in causing
  eutrophication (oxygen depletion) of water
  bodies.

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Mass Wasting

• Large volumes of sediment moving down hill slopes
  under force of gravity
• Types

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Solifluction
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Earth Flow
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Mudflow
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Debris Flow
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Slump
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Debris Slide
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Soil Creep
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Rockfall
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Avalanche