Earth’s LayersPresented by Kesler Science
1. What are the main characteristics of the Earth’s layers?
2. How can the Earth’s layers be illustrated?
Essential Questions:
Earth's Layers
Earth’s Crust• The outer layer of the Earth
• Similar to the skin on an apple (thinnest layer)
• Made up of both continental (land)and oceanic crust(under the ocean)
• 5-50 km thick
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Earth's Layers
Oceanic Crust•A thin layer of crust that overlies the ocean basins
•More dense than continental crust
•Mostly basalt rock
• Thinner that continental crust. (5-10km)
• Younger (newer) than continental crust
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Earth's Layers
Continental Crust• Layer of rock which forms the continents
• Less dense than oceanic crust
•Mostly granite
• Thicker that oceanic crust
•Older than oceanic crust
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Earth's Layers
Mantle• Largest layer of the Earth
• Under the crust about 2,890km
• Composed of silicate rocks rich in magnesium and iron
• Intense heat causes the rocks to rise and then cool and sink.
• The process is called convection, which causes the crust to move.
• Average temperature 3000o
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Earth's Layers
Lithosphere• Solid outer section of the Earth, which includes the crust(rocky layer)
•Also, includes the cool, dense, rigid upper part of the Mantle
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Earth's Layers
Asthenosphere
• Solid part of the upper mantle
• Weaker, less rigid (plasticity -like silly putty)
• Lithosphere moves over the plastic-like asthenosphere
• These plates crash into each other.
• Here the oceanic crust is subducting under the continental crust which creates volcanoes.
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Earth’s Layers
• Mesosphere
• The strong lower part of the mantle.
• Molten rock in the mesosphere flows more slowly than molten rock in the asthenosphere.
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Earth's Layers
Outer Core• Liquid layer (magma) 2,300 km
thick, second largest
• Composed of liquid iron and nickel
• Lies between inner core and mantle
• Because the magma moves around the inner core, Earth’s magnetic field is created.
• Average temperature 4000o -5000o
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Earth's Layers
Inner Core• A solid ball of metal
• 1,250 km thick
• Made of solid nickel and iron
• So hot it melts everything in the outer core
• Spins at a speed faster than the Earth rotates
• Densest layer of the Earth
• Average temperature 5000o -6000o
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Quick Action – Earth's Layers
Take a break. Get up and dance
Time for a break
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Earth's Layers
What are seismic waves?
•Waves of energy caused by earthquakes and other rock movement
•Travel through some layers of the Earth
•Recorded with seismographs
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Earth's Layers
• Seismic waves are used to determine which layers of the Earth are solid or liquid.
• Some seismic waves cannot pass through certain layers giving us a clue to the layers composition.
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Check for Understanding
Can you…
1. List the characteristics of each of the Earth’s layers?
2. Illustrate the Earth’s layers?
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Quick Action – INB Template
Earth's Layers INB Template
1. Cut out the Template.
2. Complete the Venn Diagram.
3. Paste it in your notebook.
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