Australia Notes

Geographic Location and Nomenclature of Australia

• Australia is situated entirely within the Southern Hemisphere and is popularly distinguished as "The Land Down Under."

• The name "Australia" originated from the Latin term australis, which translates to "southern."

• The official designation of the country is the Commonwealth of Australia.

• Australia is the only country in the world that occupies an entire continent.

• While it is the smallest continent globally, it is the sixth-largest country by land area.

• Other popular descriptions for Australia include the "Island Continent," "Continent State," "One Country Continent," and "Land of Migrants."

Spatial Constraints and Boundaries

• Latitudinal Extent: $10^{\circ}\text{S}$ to $40^{\circ}\text{S}$.

• Longitudinal Extent: $114^{\circ}\text{E}$ to $154^{\circ}\text{E}$.

• The Tropic of Capricorn: This latitude, measured at $23.5^{\circ}\text{S}$, passes through the approximate middle of the continent.

• Oceanic Boundaries:

  • West: Indian Ocean.

  • East: South Pacific Ocean.

  • North: Arafura Sea.

  • South: Southern Ocean.

• Regional Proximity: Australia is located south-east of mainland Asia.

Vital Statistics and Data

• Total Land Area: $7,692,000\,\text{sq. km}$.

• Total Coastline Length: $59,681\,\text{km}$.

• Mainland Coastline Length: $35,821\,\text{km}$.

• Highest Elevation: Mt Kosciuszko, standing at $2,228\,\text{m}$ above sea level.

• Lowest Point: Lake Eyre, situated at $16\,\text{m}$ below sea level.

• Official Language: English and Aboriginal languages.

• Historical Context: Most Australians are of British descent due to the country's history as a British colony. The original inhabitants are the Aborigines.

• European Discovery: Willem Janszoon, a Dutch captain of the ship The Duyfken, was the first European to make contact with the continent in late February and early March of $1606$.

Political Divisions and Major Urban Centers

Australia is comprised of eight administrative divisions, including six states and two territories:

• Western Australia: Capital is Perth.

• Northern Territory: Capital is Darwin.

• Queensland: Capital is Brisbane. Brisbane has a population exceeding $2,000,000$ and is a hub for the petroleum, paper, and metal industries.

• New South Wales: Capital is Sydney. Sydney is the largest city in Australia with approximately $4,000,000$ residents. It possesses the world's largest natural harbour and is known for its coastline, climate, and cosmopolitan culture.

• Victoria: Capital is Melbourne. Melbourne is the second-largest city with roughly $4,100,000$ people. It is Australia's largest seaport and a major center for the automobile industry.

• South Australia: Capital is Adelaide.

• Australian Capital Territory: Capital is Canberra. Canberra is the national capital and the largest inland city, with a population over $300,000$. It is located $150\,\text{km}$ from the east coast and houses the Parliament House, the High Court of Australia, the National Library, and the National Museum.

• Tasmania: Capital is Hobart.

Primary Physical Regions of Australia

The Eastern Highlands (Great Dividing Range)

• These highlands extend from Cape York in the north to Tasmania in the south, running parallel to the east coast.

• The range is narrow and high in the south but broad and low in the north.

• The eastern slope is steep, while the western slope descends gently toward the Central Lowlands.

• The mountains function as the continent's main watershed.

• Regional Names:

  • Queensland: Gregory Range.

  • New South Wales: Blue Mountains and New England Range.

  • Victoria: Australian Alps (containing Mt Kosciuszko).

Central Lowlands

• This flat, rainless region lies between the Eastern Highlands and the Western Plateau, extending from the Gulf of Carpentaria to Encounter Bay.

• It contains the world's largest artesian basin.

• Sub-divisions:

  • Carpentaria Lowlands.

  • Lake Eyre Basin (a major area of inland drainage where rivers do not reach the sea).

  • Murray-Darling Basin.

• The Great Artesian Basin: Covers $22\%$ of Australia (over $1.7\,\text{million sq. km}$), underlying parts of Queensland, New South Wales, South Australia, and the Northern Territory.

• Artesian Wells: Formed when a layer of porous rock (aquifer) is trapped between two layers of impermeable rock. When bored, water gushes out spontaneously due to natural pressure.

The Western Plateau

• Covers the western two-thirds of the continent and is composed of ancient, mineral-rich rocks, notably gold.

• The average elevation is between $300\,\text{m}$ and $450\,\text{m}$.

• The region is largely desert or semi-desert and slopes toward the Nullarbor Plain in the south.

• Mountain Ranges: Hamersley Range, MacDonnell Range, and Musgrave Range.

• Major Deserts: Gibson Desert, Great Sandy Desert, and Great Victoria Desert.

• Monoliths: The Uluru-Kata Tjuta National Park contains the world's largest monolith, Uluru.

Complementary Physical Features

• Rift Valley: Located in South Australia, featuring steep walls and small plains. It includes Lake Torrens and the Gulf of Spencer.

• The Great Barrier Reef:

  • A $2,300\,\text{km}$-long underwater ridge off the north-east coast, at distances of $16\,\text{km}$ to $240\,\text{km}$ from the shore.

  • Built by millions of coral polyps (tiny marine creatures) whose calcium carbonate skeletons accumulate into reefs.

  • UNESCO World Heritage Site containing $400$ coral types, $1,500$ fish species, and $4,000$ mollusc types.

  • Threats include illegal fishing, coastal development, and climate change.

Hydrography: Rivers and Lakes

• Australia is the world's driest continent; most rivers are seasonal, filling only during rainy seasons.

• Seasonal Rainfall: Summer in northern Australia; winter in southern Australia.

• River Systems:

  • Murray River: The longest permanently flowing (perennial) river at $2,520\,\text{km}$.

  • Darling River: The country's longest river overall at $2,739\,\text{km}$, though it is not perennial.

  • The Murray-Darling System: The largest drainage system, fed by rains in the Australian Alps. Other tributaries include the Murrumbidgee and Lachlan.

• Lakes: Most are shallow salt lakes. Significant natural lakes include Lake Eyre, Lake Torrens, Lake Gairdner, and Lake Frome (all in South Australia). Artificial lakes include Lake Argyle (Western Australia) and Lake Gordon (Tasmania).

• Artesian Water: Large supplies exist but are often too salty for human consumption or irrigation; primarily used as drinking water for livestock.

Case Study: Sheep Rearing in Australia

• Scale and Economic Impact: Australia has the third-largest sheep population globally after China and India. It contributes $16\%$ of the world’s wool and is the largest exporter of wool ($98\%$ of produce is exported).

• Population Trends: Sheep numbers have decreased from $170\,\text{million}$ in $1990$ to roughly $68\,\text{million}$.

• Regional Distribution: New South Wales ($34\%$), Western Australia ($22\%$), Victoria ($21\%$), and South Australia ($16\%$). The land between the Murray and Darling rivers is optimal for rearing.

• Merino Sheep: Highly valued for producing the best fleece. They thrive in temperate regions with rainfall between $20\,\text{cm}$ and $40\,\text{cm}$.

• Sheep Stations: Massive farms covering thousands of hectares. Families own them, but they are operated by paid laborers called jackaroos (male) and jillaroos (female).

• Operational Terms:

  • Paddocks: Smaller fenced sections of a station used to prevent overgrazing.

  • Mustering: The process of gathering sheep for shearing.

  • Shearing: Clipping the fleece using electric machines, typically occurring at the end of winter/start of summer.

  • Dingo: A wild Australian dog that poses a threat to flocks.

  • Fencing: Necessary to exclude grass-eating pests like rabbits and kangaroos.

Key Technical Definitions

• Aquifer: A porous layer of rock capable of storing and transmitting water.

• Artesian Well: A well where water rises to the surface by natural pressure from an aquifer.

• Perennial: A river that flows continuously throughout the year.

• Coral: A hard substance formed by the skeletons of coral polyps.

• Shearing: The removal of wool (fleece) from a sheep's body.

• Mustering: Gathering sheep during shearing time.

• Dingo: A wild Australian dog.

• Paddocks: Fenced subdivisions on a sheep station.

• Jackaroos/Jillaroos: Paid laborers assisting on sheep farms.