Zealandia, also known as the New Zealand continent or Tasmantis, is mostly submerged landmass in the Southwest Pacific Ocean that subsided after breaking away from Gondwanaland 79-83 million years ago. The name and the concept for Zealandia was proposed by Bruce Luyendyk in 1995.
The total land area of Zealandia is 2,86,665 square kilometres. Of this, New Zealand comprises the majority including Chatham Island. Zealandia's watery fate was sealed by the motions of the two tectonic plates that lay beneath it, the southernmost Pacific Plate and its Northern neighbour, the Indo-Australian plate. The slow separation caused Zealandia to sink.
At first, Zealandia was thought to be a microcontinent as it had broken off from Antarctica about 100 million years ago, and then from Australia about 80 million years ago. But a team of geologists from New Zealand, New Caledonia and Australia concluded that Zealandia fulfills all the requirements to be considered a drowned continent because it has the following characteristics like the other seven continents -
• High elevation related to the surrounding area: Zealandia is largely made up of two parallel ridges, separated by a failed rift. The ridges rise above the sea floor to the heights of 1000-1500 meters, with few rock islands rising above the sea level. The ridges are continental rock mainly.
• A crust thicker than ocean floor: The crust of Zealandia is thinner than usual continental floor, but thicker than ocean floor, approximately 20 km thick, and consequently they do not flow as high above the earth's mantle.
So, you won't be able to visit Zealandia unless you pack scuba gear since 94% of the 1.9 million square mile landmass lies underwater.
• A broad range of the three main type of geology
• Well defined limits
If we talk about the other natures of Zealandia, volcanic eruption is a very common thing here. The Volcanism is widespread across Zealandia but generally of low volume apart from huge mid to late Miocene Shield Volcanoes that developed the Banks and Otago Peninsulas.
Zealandia supports substantial inshore fisheries and contains gas fields. Permits of Oil exploitation in the great south basin were issued in 2007. Apart from these, offshore mineral resources include iron sands, volcanic massive sulfides and ferromanganese nodule deposits.
Geologists have been assembling their research studies for more than two decades. Nick Mortimer, a geologist at New Zealand's GNS Science Research Institutions says if we could pull the plug on the ocean, it would be clear to everybody that we have mountain chains and a big high standing continent, our 8th continent. We all hope that Zealandia will appear on the world maps in school and everywhere as the 8th continent very soon.