Earth Science: The Earth's Layers

The Earth’s Layers

• The Earth is composed of four main layers: crust, mantle, outer core, and inner core.
• Crust: The thinnest and outermost layer of the Earth, composed of solid rocks.
  • Two types of crust:
    • Oceanic Crust: Thinner, denser, and mostly composed of basalt (a dark-colored rock).
    • Continental Crust: Thicker, less dense, and mostly composed of granite (a light-colored rock).
• Mantle: The thickest layer of the Earth, located between the crust and the outer core.
  • Composed primarily of iron, silicon, and magnesium.
  • Hot, dense, and semi-solid.
• Outer Core: Liquid layer composed of iron and nickel.
  • Extremely hot (4,500 to 5,500 degrees Celsius).
  • Responsible for generating the Earth's magnetic field.
• Inner Core: Solid ball of iron and nickel.
  • About 1,220 km thick.
• Lithosphere: The rigid, outermost layer of the Earth, encompassing the crust and upper mantle.
  • Two types of lithosphere:
    • Continental Lithosphere: Includes the continental crust and upper mantle.
    • Oceanic Lithosphere: Includes the oceanic crust and upper mantle.