Layers of the earth

Layers of the Earth

• divided into the crust, mantle, outer core, and inner core

• discovered by seismic waves

Crust

• Made up of continental and oceanic crusts

• 40-70km thick

• Made up of basalt and granite

• 0-400 degrees

Mantle

• 2900 km thick

• 900 to 3700 degrees

• Made up of two layers, the lithosphere then the athenosphere

• Moves in a circular motion called convection currents

• Made up of ferro-magnesium silicate that acts like plastic

Outer core

• 2700km thick

• 3700 to 4300 dergrees

• Due to the molten iron and nickel moving it creates a magnetic field

• Does not mix with the mantle due to the density

Inner Core

• made up of solid iroon

• 1220 km in diameter

• 6000 degrees

• The iron is solid because it experiences a tremendous amount of pressure which keeps it compact

Surface wave (Seismic wave)

only travels on the surface of the earth

Body waves

• travels through the earth’s interior

• Made up of primary waves which travels through solid and liquid waves

• Made up of secondary waves which only travels through solid layers