Download The Structure of the Earth

The Structure of
the Earth
3 Composition Layers:
Based on what the
layer is made of
Compositional Layers of Earth
1. Crust
• Outer layer, very thin
• Two types of crust:
–Continental Crust (land)
– thicker & less dense
–Oceanic Crust (land under the ocean)
-thinner and more dense
How can you tell Oceanic Crust
is more Dense?
2. Mantle
• Contains 67% of Earth’s Mass
• We have not actually seen the
mantle.
• Made of solid rock that is able
to flow.
3. Core
• Made mostly of Iron and other
very dense materials.
5 Physical Layers of the Earth:
Based on the
physical state of
matter: solid, liquid,
or gas.
1. Lithosphere
• “Rock Sphere”
• Outermost rigid layer
• Divided into pieces called
tectonic plates
• Solid
• The least dense of Earth’s layers.
Tectonic Plates make up the
Lithosphere
2. Asthenosphere
• “Weak Sphere”
• Soft layer of mantle. Made of
solid rock that flows very
slowly like putty (same rate
fingernails grow).
• Solid (but can flow like a liquid)
3. Mesosphere
• “Middle Sphere”
• Strong lower mantle.
• Solid rock that flows in
circles, heating and cooling.
• Has convection currents
4. Outer Core
• Liquid layer
• Made of melted Iron
• Very Dense
• Seismic waves help us to
know this layer is liquid
5. Inner Core
• Solid
• Iron
• Most dense layer
• Iron causes magnetic fields
Structural layers