UNIT 4 — Earth Systems & Resources

Earth Structure

• Core → Mantle → Crust
  
  

• Plate tectonics cause
  
  

  • earthquakes
    
    

  • volcanoes
    
    

  • mountain building
    
    

Soil

• Made from weathered rock + organic matter
  
  

• Best soil = loam
  
  

• Contains sand + silt + clay
  
  

• Soil Horizons
  
  

  • O: organic
    
    

  • A: topsoil
    
    

  • B: subsoil
    
    

  • C: parent material
    
    

Atmosphere

• Troposphere: weather, life
  
  

• Stratosphere: ozone layer
  
  

Weather & Climate

• Climate = long term
  
  

• Weather = short term
  
  

• Hadley cells: move heat from equator to poles
  
  

El Niño

• Warms Pacific Ocean
  
  

• Decreases fish populations
  
  

• Changes global weather patterns
  
  

La Niña = opposite

Water Resources

• 97% saltwater
  
  

• Only ~1% usable freshwater
  
  

Groundwater depletion is major issue