The Real Australia

20 December 2001

Australia is a vast continent often recognised by its familiar outline. However, the 'real' Australia is very different and actually extends offshore well beyond the current coastline. Throughout Earth's history the processes of climate change, erosion and plate tectonics have altered the amount of Australia that visible above sea level.

The 'real Australia' has also changed during human history. The area under Australian jurisdiction has altered due to political decisions, international treaties and conventions that have been established over the last 250 years.

In recent times by far the greatest influence on area under Australian jurisdiction was the 1982 United Nations Convention on the Law of the Sea (UNCLOS). Under this convention Australia was able to declare a 200 nautical mile Exclusive Economic Zone (EEZ) that gave jurisdiction over some 11 million square kilometres of water, seabed and all that lies beneath.

But times are changing. Under UNCLOS, Australia also has the right to define the outer limits of its seabed jurisdiction (the legal continental shelf) where it extends beyond the EEZ. The actual definition of this extended continental shelf is a geological problem, and information to support it must be submitted to the UN Commission on the Limits of the Continental Shelf by 2004. Although this was recently extended to 2009, Australia still intends to make its submission by the original deadline.

The rocks of our continent don't end at the shoreline. They extend out beneath the ocean and form the continental margin. In some places, like off the southeast coast of Australia, the continental margin is quite narrow only extending for 60-80 km. On the northwestern side of our continent however, the margin extends for hundreds of kilometres beyond the coast. Under UNCLOS, Australia will be able to make a submission for an extension of its seabed jurisdiction to the outer limit of the submerged continent.

Geoscience Australia has nearly completed surveys and analysis to accurately define the extent of this legal continental shelf around our continent and its territories. In doing so, we will ensure that our entire potential seabed jurisdiction is included in the submission to the United Nations.

Topic contact: Last updated: October 4, 2013