PLATE TECTONICSChapter 1-2

Convection and the Mantle

Types of Heat Transfer

Heat always moves from warmer to cooler

Three types of heat transfer

Radiation – transfer of energy through space No direct contact between heat source and

object Ex. Sunlight, heat from an open fire

Conduction – transfer within a material or between materials touching Ex. Metal spoon in a pot of hot soup – you touch

the spoon and the heat conducts from the spoon to your skin.

Convection – transferred by the movement of fluids. Movement of currents within a fluid

Figure 8, p. 15

Convection Currents

Convection Current – the flow that transfers heat within a fluid

Continue as long as heat is added. Heat from the core and the mantle itself

causes convection currents in the mantle.

Figure 9, p. 16

Convection Currents in Earth

Heat from the core and the mantle cause convection currents in the mantle.

The mantle flows very slowly

Heats up at the bottom of the mantle, rises up, cools, sinks back down.

Figure 10, p. 17