Layers of Earth

Crust

• Outermost layer• Thinnest under ocean• Thickest under continent• Crust + top of mantle =

Lithosphere

Crust density

• Least dense overall layer• Oceanic crust (basalt) is more dense than• Continental Crust (granite)

Crust composition

• Solid rock—mostly silicon and oxygen• Oceanic crust—basalt• Continental crust--granite

Mantle Position

• Middle layer, thickest layer• Top portion called the

asthenosphere

Mantle Density

•Density increases with depth of increasing pressure

Mantle Composition

• Hot softened rock• Contains iron (Fe) and magnesium

(Mg)

Core position

• Inner layer• Consists of the outer and inner core

Core density

• Heaviest material; most dense layer

Core composition

• Mostly iron and nickel• Outer core—slow flowing liquid• Inner core--solid

Thickness of Layers

• Crust: (continental) 22-43 miles thick (1 % of Earth’s volume)

• Mantle: 1,800 miles thick (84% of Earth’s volume)

• Outer core: 1,400 miles thick• Inner core: 790 miles thick