Zealandia
A submerged continent in Oceania, mostly beneath the Pacific Ocean.
Zealandia, also known as Te Riu-a-Māui (Māori) or Tasmantis, is an almost entirely submerged mass of continental crust in Oceania that subsided after breaking away from Gondwana 83–79 million years ago. It has been described variously as a submerged continent, continental fragment, and microcontinent. By approximately 23 million years ago, the landmass may have been completely submerged; today, 94% remains beneath the Pacific Ocean. New Zealand is the largest part above sea level, followed by New Caledonia.
- Submerged percentage
- 94%
- Oldest estimated age
- Over 1 billion years
- Largest emergent landmass
- New Zealand
- Second largest emergent landmass
- New Caledonia
Lore & Background
Zealandia is a largely submerged continental crust that broke away from Gondwana 83–79 million years ago. By about 23 million years ago, it may have been completely submerged; today, 94% remains underwater. New Zealand and New Caledonia are the only significant landmasses above sea level. If classified as a microcontinent, it would be the world's largest, six times the area of Madagascar and more than half the exposed land area of Australia. Some geologists from New Zealand, New Caledonia, and Australia argue it fulfills all requirements to be considered a continent, noting that if not for ocean levels, it would have been recognized as such long ago.
Reader's Guide
Zealandia's significance lies in its redefinition of continental geology. Offshore mineral resources include ironsands, volcanic massive sulfides, and ferromanganese nodule deposits. Geologically, Zealandia is composed of two nearly parallel ridges separated by a failed rift, with continental crust about 20 km thick. Volcanism has occurred repeatedly, with large-volume magmatism in the Devonian and Early Cretaceous. The continent is divided into North Zealandia and South Zealandia, separated by the Alpine Fault and Kermadec Trench. Zealandia also hosts Antarctic flora, including araucarias and podocarps, and a fossilized Jurassic forest at Curio Bay. A 2006 discovery of a Miocene mammal jaw in Otago shows it once had native land mammals.
Did You Know?
- If classified as a microcontinent, Zealandia would be the world's largest, six times the area of Madagascar.
Frequently Asked Questions
What is Zealandia?
Zealandia is a massive sheet of continental crust lying beneath the Pacific Ocean in Oceania, with 94% of its surface sitting under water. It covers roughly 4.9 million square kilometres, making it nearly as large as Australia.
Why do people call Zealandia a 'lost continent'?
The nickname sticks because the landmass rifted away from Gondwana around 83–79 million years ago and has since dropped below sea level, leaving only tiny fragments exposed. Geologists use varying labels—microcontinent, continental fragment, submerged continent—depending on their preferred definition.
What parts of Zealandia are still above water?
New Zealand is the largest chunk of Zealandia that people can actually walk across, while New Caledonia holds the second-largest emergent area. The remaining 94% of the landmass lives entirely beneath the Pacific.
More in Physical & Ocean Floor Features 1-24
Elsewhere in the Physical & Ocean Floor Features universe
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record