earth structure

• Asthenosphere


  Ductile, moves under the lithosphere
• Lithosphere


  Fractures over the asthenosphere
• Discontinuities


  Place where the properties significantly change
• Moho


  Chemical boundary between the crust and the mantle, where chemical composition changes and so does density
• Gutenberg discontinuity


  Boundary between the mantle and outer core, stony to metallic composition
• Lehmann discontinuity


  Boundary between outer core and inner core, liquid to solid
• Data sources


  • Earthquakes
  • Magnetism
  • Meteorites
  • Thermal energy
  • Gravity anomalies
• Earthquakes


  Make waves that travel across the earth's surface and down through the earth, changing direction and speed as they travel. Seismic recorders placed around the earth give us data on these waves