Picture New Zealand - rising from the Pacific Ocean in two main islands, a haven of both volcanic and glacial activity. The natural diversity of the islands has made them perfect for the portrayal of other worlds, including Peter Jackson's Lord of the Rings trilogy. Now, the Geological Society of America has published evidence to suggest that not only is New Zealand not a set of islands, it is the highest mountain range of an eighth geological continent - the fantastically-named 'Zealandia'.
A paper published in the March/April edition of GSA Today argues that New Zealand, more than a fragmented collection of islands, is in fact part of a continent that is 94 per cent submerged underwater. Its isolation from Australia and large area of continental crust support the theory that it is an independent continent, elevated above the ocean crust. Claimed to be the thinnest and youngest continent on earth, the origin of Zealandia has been attributed to "widespread Late Cretaceous crustal thinning". Geologists involved in the study claim that the recognition of New Zealand as a continent and not a "collection of continental islands... more correctly represents the geology of this part of Earth".
Earth's continents are divided into two types of crusts - continental and oceanic. These are then divided into 14 tectonic plates, supplying a framework with which to understand the dynamic of Earth's history, as well as natural hazards such as earthquakes and tsunamis. Classifying Zealandia as a continent would encourage new research into the relationship between continental and oceanic plate boundaries, as well as making the area "...a useful and thought-provoking geodynamic end member in exploring the cohesion and breakup of continental crust”.
Initial estimations of Zealandia's size speculate that the continent stretches 1,500 meters north from New Zealand and the island of New Caledonia, and is approximately two-thirds the size of Australia. Geologists involved in the study say that the fact such a large body of continental crust can go overlooked for so long "illustrates that the large and the obvious in natural science can be overlooked".
Nick Mortimer, the lead geologist involved in the study, said that scientists studying the area in the past century had found granite from sub-Antarctic islands near New Zealand and metaphormic rocks on New Caledonia that were indicative of continental geology. The culmination of research published by the GSA could now transform our understanding of plate boundaries in the Pacific ocean - depending on whether the evidence is accepted or not.
While there is no international body to regulate the acceptance or dismissal of new continents, efforts to classify independent continental bodies have been denounced in the past. Efforts to classify Central America, Arabia, and greater India as continents have all been rejected. The classification of Zealandia, if accepted, could change our understanding of tectonic processes in the Pacific Ocean, and renew interest in the ocean as a wealth of hidden geological activity.
This article was originally published by WIRED UK
