Landform Geography Weathering Mass Wasting Events

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

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

Frost Wedging

Impact of Roots

Temperature Fluctuations

Salt Crystal Growth

Exfoliation

Chemical Weathering Changes rock by altering its chemical composition – water particularly important Types: –Hydrolysis –Oxidation –Carbonation –Acid Rain

Hydrolysis

Oxidation

Carbonation

Acid Rain Coal-burning power plants in Midwest emit sulfur dioxide (SO 2 ) & nitrogen oxides (NO x ) SO 2 & NO x 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

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.

Mass Wasting Large volumes of sediment moving down hill slopes under force of gravity Types:

Solifluction

Earth Flow

Mudflow

Debris Flow

Slump

Debris Slide

Soil Creep

Rockfall

Avalanche