Plate tectonics is the theory that Earth's outer layer is made up of plates, which have moved throughout Earth's history. The theory explains the how and why behind mountains, volcanoes, and ...

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 ...

On a time scale of tens to hundreds of millions of years, the geomagnetic field may be influenced by currents in the mantle. The frequent polarity reversals of Earth's magnetic field can also be ...

Plate tectonics is the widely accepted theory that the Earth's crust is divided into several sections that float around on the mantle — the mostly solid layer between the core and the crust. But how ...