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Australia, sometimes known in technical contexts by the names Sahul, Australinea or Meganesia, to distinguish it from the Australian mainland, is a continent comprising mainland Australia, Tasmania, New Guinea, Seram, possibly Timor, and neighbouring islands. It is the smallest of the seven traditional continents in the English conception. The continent lies on a continental shelf overlain by shallow seas which divide it into several landmasses—the Arafura Sea and Torres Strait between mainland Australia and New Guinea, and Bass Strait between mainland Australia and Tasmania. When sea levels were lower during the Pleistocene ice age, including the Last Glacial Maximum about 18,000 BC, they were connected by dry land. During the past ten thousand years, rising sea levels overflowed the lowlands and separated the continent into today's low-lying arid to semi-arid mainland and the two mountainous islands of New Guinea and Tasmania. Geologically, a continent extends to the edge of its continental shelf, so the now-separate islands are considered part of the continent. Due to the spread of animals, fungi and plants across the single Pleistocene landmass the separate lands have a related biota. New Zealand is not part of the continent of Australia, but of the separate, submerged continent of Zealandia. New Zealand and Australia are both part of the wider regions known as Australasia and Oceania. The term Oceania is often used to denote the region encompassing the Australian continent and various islands in the Pacific Ocean that are not included in the seven-continent model. ==Geography and name== (詳細は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, it is sometimes informally referred to as an island continent, surrounded by oceans. Archaeological terminology for this region has changed repeatedly. Prior to the 1970s, the single Pleistocene landmass was called ''Australasia'', derived from the Latin ''australis'', meaning "southern", although this word is most often used for a wider region that includes lands like New Zealand that are not on the same continental shelf. In the early 1970s, the term ''Greater Australia'' was introduced for the Pleistocene continent.〔 Then at a 1975 conference and consequent publication, the name ''Sahul'' was extended from its previous use for just the Sahul Shelf to cover the continent.〔 In 1984, W. Filewood suggested the name ''Meganesia'', meaning "great island" or "great island-group", for both the Pleistocene continent and the present-day lands, and this name has been widely accepted by biologists.〔e.g. 〕 Others have used ''Meganesia'' with different 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.〔e.g. 〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Australia (continent)」の詳細全文を読む スポンサード リンク
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