Submerged continent in the context of "Continental fragment"

Zealandia (pronounced /ziːˈlændiə/), also known as Te Riu-a-Māui (Māori) or Tasmantis (from Tasman Sea), 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. The name and concept for Zealandia was proposed by Bruce Luyendyk in 1995, and satellite imagery shows it to be almost the size of Australia. A 2021 study suggests Zealandia is over a billion years old, about twice as old as geologists previously thought.

By approximately 23 million years ago, the landmass may have been completely submerged. Today, most of the landmass (94%) remains submerged beneath the Pacific Ocean. New Zealand is the largest part of Zealandia that is above sea level, followed by New Caledonia.

The New Zealand Subantarctic Islands comprise the five southernmost groups of the New Zealand outlying islands. They are collectively designated as a UNESCO World Heritage Site.

Most of the islands lie near the southeast edge of the largely submerged continent centred on New Zealand called Zealandia, which was riven from Australia 60–85 million years ago, and from Antarctica 85–130 million years ago. They share some features with Australia's Macquarie Island to the west.