We’ve always been taught that the Earth has seven continents: Antarctica, Asia, Australia, Africa, North America, South America and Europe. Official school books sometimes are quite different from geologist’s learning. For example, they merged Asia and Europe, calling it Eurasia. So, if you ask a geologist, he would tell you that there are six continents. However, they didn’t stop there. In the latest study of The Geological Society Of America, they revealed new continent – Zealandia. The name is quite indicative in terms of continent’s geographical position. Why haven’t we noticed it till now? Because its landmass is almost entirely submerged.
Zealandia – Old Concept Gets Its Confirmations
Zealandia isn’t a new idea. The first time it was used by Bruce Luyendyk in 1995, although he uses this name to describe a region of New Zeland, Caledonia, and collection of submerged pieces and slices of crust that broke off a region of Gondwana. So, geologists took this name, finding it’s most appropriate for their discoveries. According to one of the study’s authors Nick Mortimer, this is not a sudden discovery but a gradual realization. The difference is that today geologists have enough accumulated data to publish papers with confidence.
The 11 researchers behind the GSA study claims that New Zeland and New Caledonia lies above a slab of continental crust. It covers a 4.9-million-square kilometer. Zealandia is not connected with Australia, although remarkably close to each other and 94% of the landmass is under southwest Pacific sea. The rest of it is on a surface, containing minor islands and most known North/South Islands of New Zeland and New Caledonia.
As for the continental crust thickness, Zealandia ranging from 10-30km. The highest point of the continent is Aoraki-Mt Cook. Thanks to its coherency of 4.9 Mkm2, geologists think that is qualified to be declared as a continent. Besides its size, other geological attributes such as diversity of three types of rocks, well-defined limits around landmass and land that pushes up relatively high from the ocean floor, fully meet the requirements for the continent.
On the other side, there are no official regulatory bodies which formally recognizes continents, such as for planets. Will Zealandia stay only in the geological papers or will be with time eventually included in school books, remains to be seen.