Transcript 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 – rigid rock
• Two types:
–Continental Crust (thicker)
–Oceanic Crust (thin and more
dense)
How can you tell Oceanic Crust
is more Dense?
2. Mantle
• Contains 67% of Earth’s Mass
• Made of solid rock that is able
to flow.
3. Core
• Made mostly of Iron and other
very dense materials.
5 Structural Layers of the Earth:
based on phase or what it’s like
1. Lithosphere
• “Rock Sphere”
• Outermost rigid layer
• Divided into pieces called
tectonic plates
• 15-300 Km thick
• The least dense of Earth’s layers.
Tectonic Plates make up the
Lithosphere
2. Asthenosphere
• “Weak Sphere”
• Soft layer of mantle. Low
density solid rock that flows
very slowly like putty (same
rate fingernails grow).
• 250 Km thick
3. Mesosphere
• “Middle Sphere”
• Strong lower mantle.
• High Density Solid rock that
flows in circles, heating and
cooling.
4. Outer Core
• Liquid layer
• Made of melted Iron
• Very Dense
• 2,200 Km thick
• How do we know this layer is
liquid???
5. Inner Core
• Solid Iron
• Most dense layer
• 1228 Km thick
• Iron causes magnetic fields
Structural layers