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 solid ground that we all live on forms a thin crust around the Earth. It’s no more than 50km thick - and it’s just the upper part of the lithosphere. Below it is the upper mantle. It’s mostly ...

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 ...