Geophysicist Bruce Luyendyk first proposed the term Zealandia in 1995 as a consolidated name for Campbell Plateau, Chatham Rise, Lord Howe Rise and New Zealand. More than 2 decades later, scientists have found enough evidence to declare Zealandia for what it really is and officially put it on the map as the world’s seventh geologic continent.
Based on the study entitled “Zealandia: Earth’s Hidden Continent” which was recently published in the journal “Geological Society of America”, Zealandia exhibits all the attributes needed for the land mass to be classified as a continent. The four attributes are as follows:
(1) The land mass must be at an elevation that’s high enough relative to the ocean floor.
(2) The three main types of rocks should be present: igneous rocks (spewed by volcanoes), metamorphic rocks (underwent transformation as a result of extreme heat and pressure) and sedimentary rocks (made by erosion).
(3) Compared with the ocean floor, the land should have a ‘thicker crust and lower seismic velocity structure’.
(4) The land should have ‘well-defined limits around a large enough area to be considered a continent rather than a microcontinent or continental fragment.’
When Luyendyk first coined Zealandia, it was believed to possess only the first three attributes, which meant it could not be considered as a continent, yet.
Through the use of satellite imagery and gravity maps of the sea floor, scientists were able to conclude that Zealandia is big and unified enough. In other words, it also possesses the fourth attribute which scientists previously didn’t think it did. With this discovery, the claim that Zealandia is a true continent — not a collection of microcontinents as previously thought — can now be convincingly argued.
Zealandia covers an area of 1.89 million square miles or 4.9 million square kilometers. The region is made up of land that’s mostly submerged in the Pacific Ocean and stretches from Australia’s northeastern coast past New Zealand’s islands.
If the report is to be believed, Zealandia supposedly started breaking off from supercontinent Gondwana around 100 million years ago. While making Zealandia autonomous, this pulling away also caused its crust to thin, and the region to sink, until eventually, only 6% of it remained above water, what we now know as New Zealand and the French territory New Caledonia.
According to the study done by the GNS Science Research Institute scientists, its coast may potentially contain fossil fuels worth billions of dollars. Which is why if it is confirmed as a continent, its declaration as such will have significant economic and political implications. For starters, the question of where boundary ownership ends for Australia and where it begins for New Zealand will have to be clearly addressed.
Although confirmation of Zealandia’s status is not considered an urgent matter, if it happens, Zealandia will join the list of the world’s continents which currently includes Africa, Antarctica, Australia, Eurasia, North America and South America.