continent

A continent is a large continuous mass of land conventionally regarded as a collective region. There are seven continents: Asia, Africa, North America, South America, Antarctica, Europe, and Australia (listed from largest to smallest in size). Sometimes Europe and Asia are considered one continent called Eurasia. Continents loosely correlate with the positions of tectonic plates.

Asia is the largest continent on Earth by size. It is approximately 44,614,000 square kilometres (17,226,200 square miles).

Geologists theorize that continents move. This theory is called plate tectonics, which holds that the lithosphere, the outermost layer of Earth (where continents are), lies on top of a semifluid layer of partially molten magma called the asthenosphere. Convection from the decay of radioactive elements in the mantle causes continental and oceanic plates to move.

Pangea is a landmass of the Early Permian to Early Jurassic Periods that incorporated almost all modern landmasses and is thus considered a supercontinent. Overwhelming evidence for Pangea includes similar fossil and geological records across different continents and the matching “jigsaw” shapes of today’s continents, most notably the eastern South American and western African coastlines.