Continents

A continent is a large landmass that forms part of the geographical division of the world. Continents consist of solid land and nearby islands, almost entirely surrounded by ocean. The boundary between continents is not always a water line; for example, Asia and Europe are one connected landmass, but are divided into two continents on the basis of culture and history.

There is no universal system for counting continents. The seven-continent model (Asia, Africa, Europe, North America, South America, Australia/Oceania, Antarctica) is the most widely used in English-language and Somali schools. Other systems treat the Americas as a single continent, or combine Europe and Asia under the name Eurasia, reducing the total to six or five.

How continents are divided

Division is based on a combination of geography, geology, and culture. Geologically, the solid earth is divided into large tectonic plates that move in an orderly fashion. The boundaries of these plates do not always match the continental boundaries as commonly understood. Additionally, part of each continent is covered by shallow water known as the continental shelf.

The largest continents and their populations

Asia is the largest by land area and population; more than half of the world's people live there. Africa is the second largest and includes Somalia; it is marked by climate variation and rapid population growth. Antarctica has no permanent population; it has research stations maintained by various countries. Australia is the smallest if Oceania is counted as a single continent.

The history of continental movement

Science in the twentieth century established that continents have not always remained in their present locations. The idea of continental drift was developed by earlier scientists and was later explained through the theory of tectonic plates. The solid earth was once joined in a single supercontinent called Pangaea, which broke apart millions of years ago. Movement continues today, but is measured at only a few centimetres per year.