Convection Currents and the Mantle

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Convection Currents and the Mantle

• Heat Transfer

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Heat Transfer

• Earths molten outer core is nearly as hot as the
  surface of the sun.
• Heat is transferred from the core to the surface
  of the Earth through liquids and solids.

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Heat Transfer

• Heat Transfer is the movement of energy from a
  warmer object to a cooler object.

What heat transfer?
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Heat Transfer

• There are three types of heat transfer
• Radiation
• Conduction
• Convection

What are the types of heat transfer?
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Radiation

• Radiation is the transfer of energy through
  empty space.

What is radiation?
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Radiation

• Example
• Sunlight is radiation that warms the Earths
  surface
• Heat you feel from around an open flame or fire

Radiation
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Conduction

• Conduction is heat transfer by direct contact of
  particles of matter.

What is conduction?
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Conduction

• Example
• Heat is transferred from the hot soup and the pot
  to the particles that make up the spoon.

Heat transferred to the particles of the spoon
from the pot and hot water
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Convection
What is convection?

• Convection is heat transfer by the movement of a
  heated fluid
• During convection heated particles of fluid begin
  to flow. Transferring heat energy from one part
  of the fluid to another.

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Convection

• Heat transfer by convection is caused by
  differences of temperature and density within a
  fluid.
• Density - Is a measure of how much mass there is
  in a volume of a substance.

What causes convection?
What is density?
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Convection Current

• A constant flow begins as the cooler fluid
  continually sinks to the bottom of the pot and
  the warmer fluid rises.
• Convection Current is the flow that transfers
  heat within a fluid

What is a convection current?
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Convection
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Convection Current

• The heating and cooling of the fluid, changes in
  the fluids density and the force of gravity
  combine to set convection currents in motion.

What sets convection currents in motion?
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Convection and the Earths Mantle

• Earths mantle responds to heat.
• Convection currents flow in the Asthenosphere.
• The heat source for these currents come from the
  Earths core and from the mantle itself.

Where does the heat source for the Earths
currents come from?
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Convection and the Earths Mantle
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Convection and the Earths Mantle
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Convergent and Divergent plates
How Earth's Inner Structure Affects Its Surface
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Stuff to do

• Complete the Heat Transfer concept map on the
  back of your note page.
• If you didnt begin or finish the Earths
  interior worksheet from yesterday pick it up from
  the red box and complete it.
• Once you have finished Earths interior, pick up
  a Whats happening during convection? Worksheet.
  
• DO NOT WRITE ON THESE WORKSHEETS!!!! ALL YOUR
  WORK MUST BE DONE IN YOUR SCIENCE NOTEBOOK!

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8th Grade Exit Slip 09/14/10

• Answer the following question
• What are the three types of heat transfer?