Australasia was a continent on Earth. It consisted of Australia, Tasmania, New Zealand, Malaysia, and the islands of Melanesia, Micronesia and Polynesia which were collectively known as Oceania. (AUDIO: The Transit of Venus)
In an address to address to the United Zone General Assembly meeting in 2017, Ramón Salamander announced highly satisfactory results from sun conservation tests in the Australasian Zone with sun-catching orbital satellites. (TV: The Enemy of the World)
At one point, Australasia was home to one of the five ioniser bases keeping back the glaciers of the second Ice Age. (TV: The Ice Warriors)
In 200,100, when the Daleks attacked Earth, Australasia was referred to as "just... gone" after a bombing run, which implied absolute destruction of the continent. (TV: The Parting of the Ways)