Image courtesy of Wikipedia (2010).

Image courtesy of Volcanolive (2010).

Earth’s interior is composed of 4 layers:

3 solid and 1 liquid

1. Crust

2. Mantle

3. Outer core

4. Inner core

Outermost layer – made of the lightest materials - rock, soil & seabed.

Divided into continental crust and oceanic crust. Thickness ranges from 8km beneath oceans to 40km beneath continents.

Continents are relatively light ‘blocks’ floating high on the upper mantle.

Seafloor is made of ‘basalt,’ a denser rock that presses deeper into the mantle.

Upper mantle and lower mantle – 2900 km thick (approx 84% of earth’s volume).

Temperature ranges – 500ºC near crust to 4,000ºC near outer core.

Primarily solid, but the rock is so hot that parts of the mantle ‘flow’ under pressure.

Hot rock rises and cooler rock descends creating slow moving currents.

Composed of Magnesium, Iron, Aluminum, Silcon and Oxygen.

Liquid layer above the inner core – shell of molten iron, 2,300 km thick.

Cooler than outer core – but still scorching hot at approx 4,500ºC .

Mostly iron, plus sulphur & nickle. Electrically conducive liquid - Creates earth’s

magnetic field.

Center of the earth - Deepest layer, 6250 km under the surface

A solid ball of an iron alloy (sulphur & nickle traces).

Solidified state due to intense pressure. 2400 km in diameter, high pressure, WHITE HOT

like the sun - approx 6000ºC.

http://www.youtube.com/watch?v=Q9j1xGaxYzY

What would it be like to journey to the centre of the earth?

Be sure to describe your journey in detail and

include facts about the layers of the earth.

o How will you get through the each layer? o What are you taking with you? o Who is going with you? o What will you see? o How will it feel? o Will you reach the earth’s core and see a

solid iron ball? o What could go wrong? o How will you return to the surface…

through a volcano… a hollow tree… a cave?