Austral Physical Geography & Ecology
*Australia is the world’s smallest continent and the second least populous.  It is also the only continent in the world to be entirely under the government of one country—which makes it the sixth largest country in the world and the largest in the region.  It covers 2,967,909 square miles.

*Australia only has one major series of mountains, the Great Dividing Range, which does create a continental divide, separating the western watershed from the eastern watershed.  It is actually a series of small ranges, none of which are much higher than the Appalachian Mountains.  The highest point in the range (and in Australia), Mount Kosciuszko, is 7,310 feet high.

*Australia has one other major highland area, the Western Plateau in central and western Australia.  It covers almost 2/3 of the country and is fairly arid.

*The dry interior of Australia is known as the outback, and is not good for much except some grazing on vast ranches called stations.  Because only 10% of the land is arable, it is sparsely populated.

*Most of the outback is outright desert:  (clockwise from north) the Great Sandy Desert, the Gibson Desert, and the Great Victoria Desert, as well as the Nullarbor (no tree) Plain.

*There are some small rivers in Australia, notably the Darling River and the Murray River in the southeast.

*In theory, Australia also has a large lake, Lake Eyre.  However, most of the time this lake is just a nearly-dry basin in the outback with just a few small lakes or mudflats to show where the entire lake should be.  During the rainy season, the lake may fill up to 5 feet deep, and a few times a century (perhaps 4 times in 100 years) it will fill to about 13 feet deep.  The salt pans of the Lake Eyre Basin are the lowest point in Australia, being about 50 feet below sea level.

*Because the interior of Australia is so inhospitable (being mostly desert and steppe, with a little savannah, most people live along the coast, which enjoys Mediterranean climates along the southwest, marine west coast climates along the southeast, and humid sub-tropical climates along the northeast.

*Australia does not have much tectonic activity today, despite being very near one of the most tectonically active places in the world, the Ring of Fire.

*Many of the islands of Oceania were created by volcanic activity, and volcanoes still erupt fairly frequently in the region. 

*New Zealand is part of the Ring of Fire, and it has a number of active volcanoes and its national parks feature hot springs, geysers, and other wonders of geothermal energy.

*New Zealand’s climate is essentially all marine west coast, while most of the rest of Oceania, including Papua New Guinea, is primarily tropical rainforest in its climate and vegetation.

*Antartica, the 5th largest continent in the world, covers about 5.4 million square miles.  Almost all of it is covered by ice, and almost all of it can be considered desert, because it receives almost no precipitation during the year.  Technically, a desert may be defined as a place receiving less than 10 inches of rainfall a year (although Köppen allows temperature to supersede that, making Antarctica a Polar climate).

*Most of Antarctica is covered by ice sheets about 1½ miles thick, some of which extend out over the ocean, apparently enlarging Antarctica during the winter (and melting to form icebergs in the summer).  Some of these ice shelves are semi-permanent, most notably the largest of them, the Ross Ice Shelf, which covers over half the Ross Sea.

*Most of the scientific research stations in Antarctica are on the Antarctic Peninsula (where temperatures occasionally rise above freezing—into the upper 30s), sometimes known as Palmer Land (the American name) or Graham Land (the British name), although currently the northern part of Palmer Land and the southern part is Graham Land.

*The Geographic South Pole, the point through which the imaginary axis on which the earth rotates passes, was found on 14 December 1911 by Roald Amundsen of Norway—an American team led by Robert Falcon Scott found it a month later, but died on the way back to the coast.

*The relative isolation of this region from the rest of the world (which was once greater, as Australia and Melanesia are on their own tectonic plate) has allowed it to develop a unique ecology beyond the Wallace Line (located between Borneo and Celebes).

*Almost all of the world’s marsupials and all of the remaining monotremes live in Australia, New Guinea, or New Zealand (or right around them).  Mammals elsewhere are mostly placental mammals.

*Monotremes are mammals that lay eggs, notably the echidna and the platypus (one of very few poisonous mammals in the world).

*Marsupials are creatures that give birth to babies that are not sufficiently developed to live on their own.  They are then raised in pouches on their mother’s bodies where they nurse and continue growing.  This makes it less likely that the young will survive birth and youth, but greatly reduces the mother’s chances of complications with pregnancy.

*Most of Australia’s famous animals are marsupials:  the kangaroo, the wallaby, the koala (which is not a bear at all), and many other creatures.  Almost all of Australia’s animals are unique to the continent, and fill niches normally filled by other creatures elsewhere.

*Australia does have a few placental mammals, notably a type of wild dog called the dingo, but this is thought to have been introduced by the Aborigines perhaps as recently as 5,000 years ago.

*Australia also has the widest variety of venomous creatures in the world, and is the only place to have more poisonous than non-poisonous snakes.

*Australia has a major problem today with invasive species:  species brought from outside the region that have spread uncontrolled by any local predators.  Wild rabbits (which eat grass and crops are a serious problem), but so are wild cats, wild goats, wild pigs, certain types of toads (brought in to eat up an earlier invasive beetle), and wild camels. 

*It is thought that, by eating up native plants, rabbits alone have wiped out an untold number of native plant species and because so many animals ate those plants, they have also rendered 1/8 of all mammalian species in Australia extinct as well.

*Australia has made serious efforts to control the rabbit population, even attempting biological warfare in 1950, when a disease that kills rabbits was released.  This killed off 5/6 of the rabbit population, but since then they have developed a resistance to it.

*Today, Australia is very careful to prevent the importation of any unapproved animal or plant live into the country.

This page last updated 5 December, 2005.