Earth’s Interior Ch 2, Lesson 3
May 10, 2015
Earth’s Interior
Ch 2, Lesson 3
Layers
• Earth’s interior is made up of layers.
• Each layer has a different composition, pressure, and temperature.
Seismic Waves
• Scientist learned about the Earth’s layers using seismic waves from earthquakes.
• Wave’s speed and direction change when going through different materials (solid rock, liquid rock, solid metal, liquid metal)
Crust
• Thin, rocky, outer layer of Earth. – Two types:
• Continental crust (continents or land)• Oceanic crust (under the ocean)
Lithosphere
• The crust and the solid uppermost layer of the mantle.
Asthenosphere
• Heated rock under the crust. – Rock is heated so much it acts like
playdough.
Mantle
• The thick middle layer of Earth– Composed of rock
The Outer Core
• A layer of melted metal (iron and nickel)
• Denser than the mantle
The Outer Core
• Solid ball of iron.
• Earth’s densest layer.
• Temperature comparable to the surface of the sun!