Layers of the Earth
What Are The Earth’s Layers ?
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Inner Core
Outer Core
Mantle
Crust
Characteristics of The Inner Core
•Solid ball due to high
pressure (most dense layer)
•1540 miles across
•3700°C = VERY HOT!
•Iron and nickel
•Intense pressure keeps it
from liquefying
Characteristic of The Outer Core
•Dense liquid molten rock
•1400 miles thick
•Mainly iron and nickel
•Some silicon
•Between mantle and inner core
•Gives Earth its magnetic field
Characteristics of The Mantle
• Parts are semimolten (silly putty)
• 1800 miles thick
• Mantle rock is more
dense than crustal
rock
• Flows in sluggish
currents
• Between crust and
outer core
The Crust
• Earth’s outer rocky surface
• 4 miles thick under oceans
• Up to 40 miles thick under
mountain ranges
• Consists of mostly “light” rocks
(granite – below continents)
(basalt – below oceans)
• Oceans cover 71% of the crust (oceanic
crust is very dense)
• Continental crust is less dense
Oceanic and Continental Crust
Note: the directions of movement
Tectonic Plates
• Earth’s crust is broken into about 19
pieces
• These plates move on top of the
asthenosphere
Earth’s Layers
• Are Earth’s layers similar
to a hard boiled egg?
How Are Earth’s Layers Similar
To a Hard Boiled Egg?
The Yolk
=core , inner & outer core
• Egg white
• =mantle
The Shell
=crust
Other Physical Structures of the
Earth’s Layers
• Lithosphere- includes the crust and the
upper most portion of the
asthenosphere.
This area glides over the rest of the
upper mantle. Zone of
earthquakes/volcanoes.
• Asthenosphere- top layer of the upper
mantle which consists of highly viscous
rock that flows slowly (like hot asphalt)