This animation shows a cross section of Earth; it illustrates a mathematical model of how convection might occur in the mantle. Diagrams of convection cells in the mantle are often highly simplified, but researchers are finding that the real world is much more complex.

In the model, red represents heated materials that are less dense than their surroundings. Dark blue represents cooler materials that are denser than their surroundings. Examine the motion of mantle material near the outer edge of the model. Consider how the motions you observe might affect Earth's tectonic plates.