Convection Currents !

On Friday we discussed convection currents in class. Convection currents can describe why plates move. Here are the notes I took from Friday:

Convection currents work like a lava lamp, the heat source is at the bottom of the lamp (like the core). The hot, less dense material floats to the top. When the material gets to the top it cools down. This forces it to sink back to the bottom. On the bottom it is heated again, and the cycle repeats.

Relating to the Earth's layers, the core is the heat source and the lithosphere is the layer that cools the material down. The core is hot because of its radioactivity. It's hard to describe with out a picture, but each individual "lava lamp" of the Earth is called a convection cell. This means that there are multiple areas where a cycle of heating and cooling material is going on.

This all relates back to plate tectonics... Converging plates exist where the material that is getting cooled sinks in two convection cells right next to each other. The cooling material travels towards each other on its way down to the core, as do the plates that sit on top of the convection cells.
Diverging plates are the opposite. They can be found where the hot material in two convection cells is traveling up to the lithosphere to get cooled. The hot material is moving away from the hot material of the convection cell next to it as it moves towards the surface. The plates that sit on top of the convection cells, therefore, move away from each other as well. A product of the diverging plates is magma as the hot material now has an opening through which to leak out of the asthenosphere.

Hope this helped!