A scientific study makes a claim that a chunk of continental shelf that is 94% submerged, with only New Zealand and New Caledonia being the only land masses currently above sea level, should be classified as a continent. The area is about two thirds of the size of Australia.
Say hello to Zealandia, a huge landmass almost entirely submerged in the southwest Pacific.
It’s not a complete stranger, you might have heard of its highest mountains, the only bits showing above water: New Zealand.
Scientists say it qualifies as a continent and have now made a renewed push for it to be recognised as such.
In a paper published in the Geological Society of America’s Journal,researchers explain that Zealandia measures five million sq km (1.9m sq miles) which is about two thirds of neighbouring Australia.
There is no official way of defining what a continent is.
You might think being above water is crucial to making the cut as a continent, but the researchers looked at a different set of criteria, all of which are met by the new kid in town.
- elevation above the surrounding area
- distinctive geology
- a well-defined area
- a crust thicker than the regular ocean floor
Abstract from Geological Society of America:
A 4.9 Mkm2 region of the southwest Pacific Ocean is made up of continental crust. The region has elevated bathymetry relative to surrounding oceanic crust, diverse and silica-rich rocks, and relatively thick and low-velocity crustal structure. Its isolation from Australia and large area support its definition as a continent—Zealandia.
Zealandia was formerly part of Gondwana. Today it is 94% submerged, mainly as a result of widespread Late Cretaceous crustal thinning preceding supercontinent breakup and consequent isostatic balance.
The identification of Zealandia as a geological continent, rather than a collection of continental islands, fragments, and slices, more correctly represents the geology of this part of Earth. Zealandia provides a fresh context in which to investigate processes of continental rifting, thinning, and breakup.
Full report (PDF): Zealandia: Earth’s Hidden Continent