Mapping the Confusion: Visual Proof That Australia Is Both a Continent and a Country

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The physical continent extends hundreds of miles past the breaking surf of Bondi or Cottesloe. Marine geology shows that sea level is a temporary cosmetic feature. Beneath shallow seas lies the Sahul continental shelf, a continuous platform of continental crust connecting Australia to its neighbors.

During the Last Glacial Maximum roughly 20,000 years ago, ocean levels dropped by roughly 120 meters. Humans and land animals traversed dry plains between the Australian mainland, Tasmania, and New Guinea. The Torres Strait and Bass Strait are shallow marine inundations over an unbroken geological cradle.

Geologically, the continent of Australia, formally termed Sahul, Meganesia, or Australinea, comprises:

• The Australian mainland
• The island state of Tasmania
• The island of New Guinea (divided politically between Papua New Guinea and Indonesia)
• The shallow continental shelf beneath the Arafura Sea and Gulf of Carpentaria

Tectonic plate boundaries reinforce this distinction. The Indo-Australian Plate moves northward at roughly 5.6 to 7 centimeters per year, colliding against the Pacific Plate. That ongoing collision produced the towering central mountain ranges of New Guinea. From a plate tectonics standpoint, Papua New Guinea shares the same continental platform as Canberra, regardless of modern international borders.