Plate boundaries are where the action is. A large fraction of all earthquakes, volcanic eruptions, and mountain building occurs at plate boundaries. It is also where most of the people on Earth live.

The diagram below shows the structure of the earth. In geography, taking a slice through a structure to see inside is called a cross section. Continental plates are usually quite thick (between 35 to ...

It’s right there in the name: “plate tectonics.” Geology’s organizing theory hinges on plates—thin, interlocking pieces of Earth’s rocky skin. Plates’ movements explain earthquakes, volcanoes, ...