Australia (Continent) 2

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Area 8,600,000 km2(3,300,000 sq mi)

Population 36,000,000 (estimated population ofAustralia, Papua New Guinea, Papua,

West Papua, Maluku Islands, Timor,

Halmahera, etc. for 2009, 6th)

Pop.

density

4.2 /km2(11 /sq mi)

Demonym Australian

Countries 4 (Australia, Papua New Guinea, East

Timor* and portions of Indonesia)

Languages English, Indonesian, Tok Pisin, HiriMotu, 269 indigenous Papuan and

Austronesian languages, Mandarin

Chinese, Italian, Arabic, Greek,

Cantonese and about 70 Indigenous

Australian languages

Time zones GMT+10, GMT+9.30, GMT+8

Internet

TLD

.au, .pg, .tl, .tp and .id

Largest

citiesList of cities in Australia by population

List of cities and towns in Papua New

Guinea by population

* Often considered as part of Asia

(South East Asia).

Australia

From Wikipedia, the free encyclopedia

Australia, sometimes known in technical contexts by the

names Sahul, Australineaor 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

landmassesthe 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.[1]

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.[2]NewZealand and Australia are both part of the wider regions

known as Australasia and Oceania.

1 Geography and name

2 Geology

3 Biogeography

4 Human habitation

5 See also

6 References List

Coordinates: 26S 141E

alia (continent) - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Australia_(

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Mainland Australia showing the continental

Sahul Shelf (light blue) extending to the

islands of New Guinea in the north, the

island of Timor in the northwest, and

Tasmania in the south

The Sahul continent

With a total land area of 8,560,000 square kilometres

(3,310,000 sq mi), the Australian continent is the smallest and

lowest-lying human-inhabited continent on Earth. The continental

shelf connecting the islands, half of which is less than 50 metres

(160 ft) deep, covers some 2,500,000 square kilometres

(970,000 sq mi), including the Sahul Shelf[3][4]

and Bass Strait. As

the country of Australia is mostly on a single landmass, and

comprises most of the continent, it is sometimes informally referredto as an island continent, surrounded by oceans.[5]

Archaeological

terminology for

this region has

changed

repeatedly. Prior

to the 1970s,

the single

Pleistocene

landmass wascalled

Australasia,[6]

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

ustraliawas introduced for the Pleistocene continent.[6]

Then at a 1975 conference and consequent publication,[7]

the name Sahulwas extended from its previous use for just the Sahul Shelf to cover the continent.[6]

In 1984, W. Filewood suggested the nameMeganesia, meaning "great island" or "great island-group", for both

the Pleistocene continent and the present-day lands,[8]

and this name has been widely accepted by biologists.[9]

Others have usedMeganesiawith different meanings: travel writer Paul Theroux included New Zealand in his

definition[10]

and others have used it for Australia, New Zealand and Hawaii.[11]

Another biologist, Richard

Dawkins coined the nameAustralineain 2004.[12]Australia-New Guineahas also been used.[13]

The continent primarily sits on the Indo-Australian Plate. Because of its central location on its tectonic plate

Australia doesn't have any active volcanic regions, the only continent with this distinction.[14]

The lands were

oined with Antarctica as part of the southern supercontinent Gondwana until the plate began to drift north

about 96 million years ago. For most of the time since then, AustraliaNew Guinea remained a continuous

landmass. When the last glacial period ended in about 10,000 BC, rising sea levels formed Bass Strait,

separating Tasmania from the mainland. Then between about 8,000 and 6,500 BC, the lowlands in the north

were flooded by the sea, separating New Guinea, the Aru Islands, and the Australian mainland.

A northern arc consisting of the New Guinea Highlands, the Raja Ampat Islands, and Halmahera was uplifted by

the northward migration of Australia and subduction of the Pacific Plate. The Outer Banda Arc was accreted


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along the northwestern edge the continent; it includes the islands of Timor, Tanimbar, and Seram.[15]

As the continent drifted north from Antarctica, a unique fauna, flora and mycobiota developed. Marsupials and

monotremes also existed on other continents, but only in AustraliaNew Guinea did they out-compete the

placental mammals and come to dominate. Bird life also flourished, in particular the ancestors of the great

passerine order that would eventually spread to all parts of the globe and account for more than half of all livingavian species. Among the fungi, the remarkable association between Cyttariagunnii(one of the "golf-ball"

fungi) and its associated trees in the genusNothofagusis evidence of that drift: the only other places where this

association is known are New Zealand and southern Argentina and Chile.[16]

Animal groups such as macropods, monotremes, and cassowaries are endemic to Australia. There were three

main reasons for the enormous diversity that developed in animal, fungal and plant life.

While much of the rest of the world underwent significant cooling and thus loss of species diversity,

AustraliaNew Guinea was drifting north at such a pace that the overall global cooling effect was roughly

equalled by its gradual movement toward the equator. Temperatures in AustraliaNew Guinea, in other

words, remained reasonably constant for a very long time, and a vast number of different animal, fungal

and plant species were able to evolve to fit particular ecological niches.

Because the continent was more isolated than any other, very few outside species arrived to colonise, and

unique native forms developed unimpeded.

Finally, despite the fact that the continent was already very old and thus relatively infertile, there are

dispersed areas of high fertility. Where other continents had volcanic activity and/or massive glaciation

events to turn over fresh, unleached rocks rich in minerals, the rocks and soils of AustraliaNew Guinea

were left largely untouched except by gradual erosion and deep weathering. In general, fertile soils

produce a profusion of life, and a relatively large number of species/level of biodiversity. This is because

where nutrients are plentiful, competition is largely a matter of outcompeting rival species, leaving great

scope for innovative co-evolution as is witnessed in tropical, fertile ecosystems. In contrast, infertile soils

tend to induce competition on an abiotic basis meaning individuals all face constant environmental

pressures, leaving less scope for divergent evolution, a process instrumental in creating new species.

For about 40 million years AustraliaNew Guinea was almost completely isolated. During this time, the

continent experienced numerous changes in climate, but the overall trend was towards greater aridity. When

South America eventually separated from Antarctica, the development of the cold Antarctic Circumpolar

Current changed weather patterns across the world. For AustraliaNew Guinea, it brought a marked

intensification of the drying trend. The great inland seas and lakes dried out. Much of the long-established

broad-leaf deciduous forest began to give way to the distinctive hard-leaved sclerophyllous plants that

characterise the modern Australian landscape.

For many species, the primary refuge was the relatively cool and well-watered Great Dividing Range. Even

today, pockets of remnant vegetation remain in the cool uplands, some species not much changed from the

Gondwanan forms of 60 or 90 million years ago.


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Eventually, the AustraliaNew Guinea tectonic plate collided with the Eurasian plate to the north. The collision

caused the northern part of the continent to buckle upwards, forming the high and rugged mountains of New

Guinea and, by reverse (downwards) buckling, the Torres Strait that now separates the two main landmasses.

The collision also pushed up the islands of Wallacea, which served as island 'stepping-stones' that allowed plants

from Southeast Asia's rainforests to colonise New Guinea, and some plants from AustraliaNew Guinea to move

into Southeast Asia. The ocean straits between the islands were narrow enough to allow plant dispersal, but

served as an effective barrier to exchange of land mammals between AustraliaNew Guinea and Asia.

Although New Guinea is the most northerly part of the continent, and could be expected to be the most tropicalin climate, the altitude of the New Guinea highlands is such that a great many animals and plants that were once

common across AustraliaNew Guinea now survive only in the tropical highlands where they are severely

threatened by overpopulation pressures.

Humans first populated eastern Wallacea (including Timor, which at the time was separated from mainland

Sahul), the rest of Sahul, and the Bismarck Archipelago from Sunda about 45,000 years ago, by a founding

population estimated to have been at least several hundred, and having had relatively sophisticated water craft.

There was little subsequent population mixing between Wallacea and Sahul for about 30,000 years, and indeedrelatively little mixing between the north and south and the east and west of Sahul after the initial dispersal of

the population.[17]

Outline of Australia

Pacific Islands

Paleoclimatology

Plate tectonics

^Johnson, David Peter (2004). The Geology of

Australia. Port Melbourne, Victoria: Cambridge

University Press. p. 12.

1.

^Keith Lewis; Scott D. Nodder and Lionel Carter

(2007-01-11). "Zealandia: the New Zealand

continent" (http://www.teara.govt.nz/EarthSeaAndSky

/OceanStudyAndConservation/SeaFloorGeology

/1/en). Te Ara Encyclopedia of New Zealand.

Retrieved 2007-02-22.

2.

^"Big Bank Shoals of the Timor Sea: An

environmental resource atlas"

(http://www.aims.gov.au/pages/reflib/bigbank/pages

/bb-04.html). Australian Institute of Marine Science.

2001. Archived (http://web.archive.org

/web/20060908082408/http://www.aims.gov.au/pages

/reflib/bigbank/pages/bb-04.html) from the original

on 8 September 2006. Retrieved 2006-08-28.

3.

^Wirantaprawira, Dr Willy (2003). "Republik

Indonesia" (http://www.wirantaprawira.net/indon

/land.html). Dr Willy Wirantaprawira. Retrieved

2006-08-28.

4.


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^Lffler, Ernst; A.J. Rose, Anneliese Lffler &

Denis Warner (1983).Australia:Portrait of a

Continent. Richmond, Victoria: Hutchinson Group.

p. 17. ISBN 0-09-130460-1.

5.

^ abcBallard, Chris (1993). "Stimulating minds to

fantasy? A critical etymology for Sahul". Sahul in

review: Pleistocene archaeology in Australia, NewGuinea and island Melanesia. Canberra: Australian

National University. pp. 1920.

ISBN 0-7315-1540-4.

6.

Âllen, J.; J. Golson and R. Jones (eds) (1977).

Sunda and Sahul: Prehistorical studies in Southeast

Asia, Melanesia and Australia. London: Academic

Press. ISBN 0-12-051250-5.

7.

^Filewood, W. (1984). "The Torres connection:

Zoogeography of New Guinea". Vertebratezoogeography in Australasia. Carlisle, W.A.:

Hesperian Press. pp. 11241125.

ISBN 0-85905-036-X.

8.

ê.g. Flannery, Timothy Fridtjof (1994). The future

eaters: An ecological history of the Australasian

lands and people. Chatswood, NSW: Reed. pp. 42,

67. ISBN 0-7301-0422-2.

9.

^Theroux, Paul (1992). The happy isles of Oceania:

Paddling the Pacific. London: Penguin.

ISBN 0-14-015976-2.

10.

^Wareham, Evelyn (September 2002). "From

Explorers to Evangelists: Archivists, Recordkeeping,

and Remembering in the Pacific Islands".Archival

Science2(34): 187207. doi:10.1007/BF02435621

(http://dx.doi.org/10.1007%2FBF02435621).

11.

^Dawkins, Richard (2004). The ancestor's tale: A

pilgrimage to the dawn of evolution. Boston:

Houghton Mifflin. p. 224. ISBN 0-618-00583-8.

12.

ê.g. O'Connell, James F.; Allen, Jim (2007).

"Pre-LGM Sahul (Pleistocene Australia-New

Guinea) and the Archaeology of Early Modern

Humans" (http://www.anthro.utah.edu/PDFs/joc/32o_conn.pdf). In Mellars, P.; Boyle, K.; Bar-Yosef,

O. et al.Rethinking the Human Revolution.

Cambridge: McDonald Institute for Archaeological

Research. pp. 395410.

13.

^Barrett; Dent (1996).Australian Environments:

Place, Pattern and Process

(http://books.google.com.au

/books?id=9AUcU_35C9sC). Macmillan Education

AU. p. 4. ISBN 0732931207. Retrieved 13 June2014.

14.

^MG Audley-Charles, 1986, "TimorTanimbar

Trough: the foreland basin of the evolving Banda

orogen", Spec. Publs int. Ass. Sediment, 8:91102

15.

^Korf, R.P. Cyttaria(Cyttariales): coevolution with

Nothofagus, and evolutionary relationship to the

Boedijnpezizeae (Pezizales, Sarcoscyphaceae).

pp. 7787 in K.A. Pirozynski & J. Walker [eds]

Pacific Mycogeography: a Preliminary Approach.

Australian Journal of BotanySupplementary Series

No. 10, 172 pp. (1983).

16.

^ http://www.anthro.utah.edu/PDFs/OC_A_2012.pdf17.

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Australia (Continent) 2