Geology? Newly identified continent Zealandia faces a battle for recognition

Introversion · Jun 8, 2017

Defining the largely submerged landmass may be trickier than defining Pluto as a planet

Science News said:
Lurking beneath New Zealand is a long-hidden continent called Zealandia, geologists say. But since nobody is in charge of officially designating a new continent, individual scientists will ultimately have to judge for themselves.

A team of geologists pitches the scientific case for the new continent in the March/April issue of GSA Today, arguing that Zealandia is a continuous expanse of continental crust covering around 4.9 million square kilometers. That’s about the size of the Indian subcontinent. Unlike the other mostly dry continents, around 94 percent of Zealandia hides beneath the ocean. Only New Zealand, New Caledonia and a few small islands peek above the waves.

“If we could pull the plug on the world’s oceans, it would be quite clear that Zealandia stands out about 3,000 meters above the surrounding ocean crust,” says study coauthor Nick Mortimer, a geologist at GNS Science in Dunedin, New Zealand. “If it wasn’t for the ocean level, long ago we’d have recognized Zealandia for what it was — a continent.”

The landmass faces an uphill battle for continent status, though. Unlike planets and slices of geologic time (SN: 10/15/16, p. 14), no international panel exists to officially rubber-stamp a new continent. The current number of continents is already vague — usually given as six or seven, with geologists referring to Europe and Asia collectively as Eurasia. Proponents will just have to start using the term “Zealandia” and hope it catches on, Mortimer says.

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blacbird · Jun 13, 2017

The significance of this discovery is that the submerged land mass is made of continental crust material, which is much different than oceanic crust material, being less dense and much thicker. While new oceanic crust is being formed constantly by plate tectonic spreading centers, like that in the mid-Atlantic, continental crust builds more slowly and less regularly, via a combination of igneous, sedimentary and metamorphic processes. What researchers now need to do is figure out the history of that submerged continent, which, being submerged, won't be easy. But a hell of a lot of fun for geologists. Whatever they want to call it matters less than an understanding of what it is, same as with the Pluto controversy.

The issue also rests on who is doing the defining. Geographers define continents differently than geologists do. India, to a geographer, is simply a big peninsula of Asia. To a geologist, it is a separate individual tectonic plate.

caw

Alessandra Kelley · Jun 13, 2017

It's continental crust.

Furthermore, Zealandia was not always flooded. There are apparently remnants of fossil forests and creatures.

Drowned continent is still continent, in my opinion.

Geology? Newly identified continent Zealandia faces a battle for recognition

Introversion

Pie aren't squared, pie are round!

blacbird

Alessandra Kelley

Sophipygian