Boundaries between the continents of Earth Boundaries between the continents of Earth The boundaries between the continents of Earth are generally a matter of geographical convention. Several slightly different conventions are in use. The number of continents is most commonly considered seven but may range as low as four when the Americas and Afro-Eurasia are each considered a single continent. According to the definition of a continent in the strict sense, an island cannot be part of any continent, but by convention and in practice most major islands are associated with a continent. There are three overland boundaries subject to definition: While the isthmus between Asia
Australia (continent) meanings: travel writer Paul Theroux included New Zealand in his definition and others have used it for Australia, New Zealand and Hawaii. Another biologist, Richard Dawkins, coined the name "Australinea" in 2004. "Australia-New Guinea" has also been used. With a total land area of , the Australian continent is the smallest, and second-lowest human inhabited (after Antarctica) continent on Earth. The continental shelf connecting the islands, half of which is less than deep, covers some , including the Sahul Shelf and Bass Strait. As the country of Australia is mostly on a single landmass, and comprises most of the continent,