Earth's Interior

Indirect Evidence

• deep wells & mines
• earthquake waves

Temperature & Pressure increase with depth in the geosphere.

Crust

• thinnest
• least dense
• brittle, rocky
• continental (denser) & oceanic (thinner)

Mantle

• middle; thickest; denser than crust
• mostly rock; more iron & magnesium than crust

Layers of Mantle

• Uppermost (part of lithosphere); rigid
• Asthenosphere (plastic; flowing rock b/c of greater heat)
• Upper & Lower Mantle (hotter but more pressure so no flowing)

Core

• metallic (mostly iron)
• densest
• 2 layers

Layers of Core

• Outer core
• liquid
• Inner core
• solid; spins faster than rest of Earth

Geomagnetism

• spinning core creates magnetic field around Earth
• outer part is magnetosphere