1. Convection Currents and the Mantle
OBJECTIVES:
Explain how heat is transferred
Identify what causes convection currents

2. Radiation The transfer of energy through empty space Examples:
-Sunlight
-Open flame

3. Conduction
Heat is transferred by direct contact of particles of matter
Heat travels from hot to cold
Examples:
Hot frying pan, Fire poker stick

4. Convection
The movement of a fluid, caused by differences in temperature and density, that transfers heat from one part of the fluid to another
Examples:
-Heating water
-Mantle in the Asthenosphere
-Air --wind

5. Checkpoint-1
What are the three types of heat transfer?

6. ANSWER-1
RADIATION
CONDUCTION
CONVECTION

7. Checkpoint-2
Describe how convection currents form?

8. ANSWER-2
The heating and cooling of a fluid changes in a fluid’s density, and the forces of gravity combine to set convection currents in motion.

9. Checkpoint-3
In general, what happens to the density of a fluid when it becomes hotter?

10. Answer-3
In general, when a fluid is heated, its density decreases. --i.e.steam and ice

11. Checkpoint-4
What happens to convection currents when a fluid reaches a constant temperature?

12. ANSWER-4
When a fluid reaches a constant temperature, the convection currents stop.