Earth science

• Atmosphere


  Extends outward about 10 000 km from the surface of the Earth
• Composition of the atmosphere

  • 78.1% nitrogen
  • 20.9% oxygen
  • 0.9% argon
  • 350 ppm carbon dioxide
• Layers of the atmosphere

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere
• Troposphere


  • Extends to about 14.5 km above the Earth's surface
  • Where the weather forms
• Stratosphere


  • Found 14.5 to 50 km above the Earth's surface
  • Contains the ozone layer that protects the Earth from the Sun's harmful UV radiation
• Mesosphere


  • Extends from 50 to 85 km above the Earth's surface
  • Protects the Earth from the impact of space debris
• Thermosphere


  • Found 85 to 600 km above the Earth's surface
  • Contains charged particles affected by the Earth's magnetic field, creating the Auroras
• Exosphere


  • The farthest layer, extending to about 10 000 km above the Earth's surface
• Geosphere


  Includes all the soil, rocks, and minerals present in the crust to the core of the Earth
• Layers of the geosphere

  • Crust
  • Mantle
  • Core
• Crust


  • The outermost layer of the geosphere
  • Made mostly of silicate materials
  • Two types: oceanic crust and continental crust
• Oceanic crust


  • Lies beneath the oceanic floors
  • About 5 to 10 km thick
• Continental crust


  • Makes up the continents
  • About 15 to 70 km thick
  • Made mostly of silicate rocks rich in magnesium and iron
• Mantle


  • About 2900 km thick
  • Has increasing temperatures at increasing depths
• Core


  • Has a radius of 3400 km
  • The innermost layer of the Earth
  • Made out of iron and nickel