Correction
I've seen the
7 Continenets reduced to
4 Continents at
http://wikipedia.org/wiki/Continents . I've now found this at
http://mapsofworld.com/continents
The Earth's land is separated into large landmasses called
continents. One definition of the term continent describes distinct and separate large landmasses, like Australia and Antarctica, which are disconnected from any other land.
Other common practices allows a looser definition of the term, which defines continents based on additional factors, separating Europe from Asia or North America from South America.
The World Continent map shows 7 continents, but there are other models that show 6 continents, 5 continents, or 4 continents, created by considering certain continents one entity rather than two entities.
The continental landmasses are concentrated more in the Northern Hemisphere than in the Southern Hemisphere in terms of area.
In terms of area, Asia leads the continents in size, followed by Africa, North America, South America, Antarctica, Europe, and Australia.
Division of Continents
The Isthmus of Suez connects the continents of Asia and Africa, the Isthmus of Panama joins North and South America. Comparing to the area of landmasses that these isthmuses join, both of those are quite narrow.
No isthmus or sea separates Asia from Europe, which explains reasoning behind the concept of
Eurasia, that is Europe and Asia as a single continent. This is one of the six-continent models of the world. This view, held by some geographers, is generally only popular in Russia, some Eastern European countries and Japan.
The continents of North America and South America are usually considered separate continents, though earlier in history, they were viewed as single continents and were known collectively as America. Even today, some countries in South America consider the two to be one continent.
Another theory relating to the division of continents came as the four-continent model. In this model, continents are defined as discrete landmasses. According to the theory Asia, Europe and Africa form a single continent called Afro-Eurasia, and the total number of continents becomes four: Afro-Eurasia, America, Antarctica, and Australia.
Continent Models
7 Continents: North America, South America, Antarctica, Africa, Europe, Asia, Australia
6 Continents: North America, South America, Antarctica, Africa, Eurasia, Australia
6 Continents: America, Antarctica, Africa, Europe, Asia, Australia
5 Continents: America, Antarctica, Africa, Eurasia, Australia
4 Continents: America, Antarctica, Afro-Euroasia, Australia
