The crust of the Earth is broken up into small pieces called Tectonic Plates. Each of these plates is being moved by the convection cell in the Asthenosphere underneath it. As these plates move they end up colliding (hitting) other plates, pulling apart, or sliding against one another. As the large pieces of crust move against each other they produce vibrations in the form of earthquakes. The movement of the plates also causes a lot of volcanic activity.
Because of the large number of earthquakes and volcanoes that happen at these plate boundaries scientists were able to map them out in order to determine the size and shape of most of the tectonic plates.
The picture below shows a map of all of the earthquakes and volcanoes that happened from 1963 to 1998. This can be compared to the map of the known location of plate boundaries (edges) right below the first picture.
The map below shows the major tectonic plates. Students will be required to memorize the location and name of each one. Spelling will count.