Australian Antarctic Territory

Territorial regions of Antarctica. ¿¿ Australian Antarctic Division.

Territorial regions of Antarctica.
© Australian Antarctic Division.

The Australian Antarctic Territory, which is situated from 60°S latitude to the South Pole and between longitudes 160°E and 45°E, is administered by the Department of Sustainability, Environment, Water, Population and Communities through its Australian Antarctic Division.

Antarctica is the fifth largest continent in the world and rates as the driest, coldest and windiest of all continents. The rocky landmass of Antarctica is seven million square kilometres with a coastline stretching 7500 kilometres. However, an offshore ice shelf extending well beyond the lass mass results in the accessible coastline varying from season to season. In the summer months, the ice shelf and continent total 14 million square kilometres in area with a diameter of 4500 kilometres. In winter, the freezing of the surrounding seas effectively doubles the size to more than 30 million square kilometres or almost four times the size of the Australian mainland.

Because of the freezing conditions, most of the continent, including its mountains, is covered by a smothering overlay of ice. In places the ice cap can reach a thickness of 4700 metres and fills deep trenches which otherwise would lie below sea level. The highest mountain, Vinson Massif, peaks at 5140 metres.

The highest recognised mountains in the Australian Antarctic Territory are Mt McClintock in the eastern sector at 3490 metres and Mt Menzies in the western sector at 3355 metres, both considerably higher than the highest mountain on the Australian mainland, Mount Koscuiszko at 2228 metres. Elevations in excess of 4000 metres exist in the western sector in the vicinity of 82°E 56°S and, although these are generally not considered mountains, the definition is frequently debated.

The region's intense coldness is maintained through two major wind currents. These circular wind currents also influence the ocean currents and together they isolate the Antarctic region from the presence of warmer waters from the north. Wind speeds can reach up to 320 kilometres an hour, especially in the coastal regions. These winds are called katabatic winds and result from supercooled, dense air moving down unimpeded ice slopes.

The thick ice covering Antarctica assists marine life in providing insulation to the water and allowing certain forms of life such as micro algae to grow. The algae is released in summer and is consumed by krill and other small animals. The krill is at the bottom of the food chain in the Southern Ocean and are essential to life in this ecosystem.

Territorial regions of Antarctica. ¿¿ Australian Antarctic Division.

Supply ship Aurora Australis
at Mawson Base.
© Geoscience Australia
Mark Alcock 1997.

Australia has a long historic connection with Antarctica dating back to the Australasian Antarctic Expedition led by geologist Sir Douglas Mawson. The object was to explore the Antarctic continent in the vicinity of the magnetic south pole. This expedition lasted from 1911 until 1914. The hut occupied by the expedition is included as an historic site on Australia's Commonwealth Heritage List. A second expedition, the British Australian and New Zealand Antarctic Research Expedition, also led by Sir Douglas Mawson, was to claim formal possession of King George V land while at Cape Dension. This expedition included two visits between the years 1929 and 1931. There have been frequent expeditions since 1947 and all have been under the Australian National Antarctic Research Expedition banner. These expeditions have included visits to nearby Heard and McDonald Islands and Macquarie Island.

Since 1954 when the Australian National Antarctic Research Expedition established the Mawson base on the coast of MacRobertson Land, Australia has maintained a continuous scientific presence in Antarctica. Australia maintains two other bases, Casey and Davis.