Transcript Inside the Earth

Inside the Earth
Composition (What it is made of)
• Crust (solid)
– Oxygen
– Silicon
– Aluminum
• Mantle (flows putty)
– Oxygen
– Silicon
– Iron
• Core (mostly iron)
The Crust
• Outer layer
• 5 - 100 km thick
• 2 types of crust
– Oceanic (very dense,
made of basalt)
– Continental (less dense)
• Porous
– Tiny spaces
– Less dense
Oceanic and Continental Crust
The Mantle
•
•
•
•
Middle layer
Very thick layer
Convection (flows)
Hot spot activity
The Core
•
•
•
•
Made mostly of iron
1/3 of the Earth’s mass
Very hot
Outer core of liquid iron
creates our magnetic fields
• Pressure makes inner core
solid
Earth’s Layers
• How are the earth’s
layers similar to an egg?
• Shell = crust
• Egg white = mantle
• Yolk = core
• Can you think of another
object that works?
Physical Structure of the Earth
• Lithosphere
– Rigid outer layer (crust)
– Includes part of mantle
• Asthenosphere
– Solid rock that flows slowly (like hot asphalt)
– The top part of the mantle
• Outer Core
– Liquid layer
– Causes magnetic poles
• Inner Core
– Solid due to pressure, very dense
Tectonic Plates
• Earth’s lithosphere is broken into around 20 pieces
• These plates move on top of the asthenosphere
• Convection causes speed and direction