Heat Transfer and Convection Currents

Science, Grade 6


Table Of Contents: Heat Transfer and Convection Currents

1. Types of Heat Transfer
There are three types of heat transfer. Radiation is heat transferred through space. Conduction is heat transferred within a material, and convection is heat transferred by the movement of liquids.
2. What Causes Convection?
Convection is caused when a fluid has differences in temperature and density. When a liquid becomes cooler, its particles move more slowly and the liquid becomes denser.
3. Hot Mantle Rises
In the Earth, the mantle is the hottest near the core and cooler near the crust. Because it has a lower density, the hot mantle material near the core starts to rise toward the crust.
4. Cool Mantle Sinks
As the mantle rises, it also cools. When it cools, it becomes denser and then descends back towards the center of the Earth.
5. Mantle Convection Currents
This circular motion creates convection currents. Convection currents in the mantle cause the crust to move over Earth’s surface.
6. Core Convection Currents
There are also convection currents in the outer core. These currents contribute to the Earth's magnetic field.