1. Convection in the Mantle
Khan Academy Convection in the Mantle Video

2. Remember the three types of heat transfer?
Radiation
Conduction
Convection

3. Remember density?
Amount of mass in a given volume Decreases as a substance is heated because molecules move faster, bounce around more and take up more space.... Increases as a substance cools....

4. Changes in fluid density
CONVECTION
Flow that transfers heat within a fluid caused by
Heating & Cooling
of a fluid
Changes in fluid density
gravity

5. CONVECTION CURRENT When a fluid is heated its density decreases
...heat goes higher
...Hot air, hot water, hot rock rise
When a fluid cools, its density increases
....Cold creeps lower
....Cold air, cold water, cool rock sink

6. Mantle rocks near Earth’s hot core are heated and become less dense than cooler, upper mantle rocks. These hotter rocks rise & the cooler rocks sink, creating slow convection currents, or convection cells.

7. Convection cells in the mantle – in the asthenosphere - cause the lithosphere to move.

8. Ridge-push Hypothesis
Spooner, Alecia, Geology for Dummies, Wiley Publishing, 2011

9. Slab-Pull hypothesis
Spooner, Alecia, Geology for Dummies, Wiley Publishing, 2011

10. Magma Plumes hypothesis
Spooner, Alecia, Geoplogy for Dummies, Wiley Publishing, 2011