The landmass – about two-thirds the size of Australia – of which 94% is under water, is a step closer to being recognised, scientists say

This article is more than 2 years old

This article is more than 2 years old

Zealandia – a new continent submerged in the southwest Pacific – is a step closer to being recognised, the authors of a new scientific paper claim.

A paper published in GSA Today, the journal of the Geological Society of America, contends that the vast, continuous expanse of continental crust, which centres on New Zealand, is distinct enough to constitute a separate continent.

The paper’s authors argue that the incremental way in which it came to light goes to show that even “the large and the obvious in natural science can be overlooked”.

Zealandia covers nearly 5m square km, of which 94% is under water, and encompasses not only New Zealand but also New Caledonia, Norfolk Island, the Lord Howe Island group and Elizabeth and Middleton reefs.

The area, about the same size as the Indian subcontinent, is believed to have broken away from Gondwana – the immense landmass that once encompassed Australia – and sank between 60m and 85m years ago.

“This is a big piece of ground we’re talking about, even if it is submerged,” said Nick Mortimer, a New Zealand geologist who co-authored the paper.

Geologists have argued in favour of Zealandia being recognised as its own continent intermittently over the past 20 years.

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The American geophysicist Bruce Luyendyk was the first to apply the name Zealandia to a south-west Pacific continent in 1995. Since then, the paper’s co-authors say, it has had “moderate uptake” but was still not broadly known to international scientists.

Mortimer and his fellow co-authors from the GNS Science research institute and Victoria University of Wellington in New Zealand; the Service Géologique of New Caledonia; and the University of Sydney’s School of Geosciences contend that Zealandia has the necessary geological elements to be considered a continent.

Mortimer told Guardian Australia that it was the first robust, peer-reviewed scientific paper to define and describe Zealandia, but its findings would offer “nothing new” for most New Zealand geoscientists. “They probably wonder what all the fuss is about.”

He said he and other researchers began to piece together the submerged continent with the release of a bathymetric map in 2002.

“That’s when the penny dropped, really ... From that point, that map was literally our road map for some crosses, just trying to get rocks out of all the four corners of Zealandia that we could, so we could prove up the geology.”

There had been no formal Zealandia project, he said; it had been “a gradual process ... [of] joining the dots”.

“It was a question of confidence, fundamentally, I think, with the accumulation of data and what to do with it.”

Facebook Twitter Pinterest Zealandia shown on a map of world continents. Photograph: GNS Science

Zealandia would be the world’s seventh and smallest continent, after Eurasia, Africa, North America, South America, Antarctica, and Australia. (Europe and Asia are sometimes recognised separately, despite being the same landmass.)

“It turns out New Zealand isn’t just a couple of small islands at the bottom of the world,” Fairfax Media New Zealand triumphantly reported.



Barry Kohn, a professor of earth sciences at the University of Melbourne, who had done work with Mortimer on Zealandia in the past, said there was a “fair consensus in the scientific community” in favour of its existence.

“It’s pretty clear that that whole area is not part of the ocean. It’s got all the hallmarks of a continent.”

He said rock dredged up from the area was clearly continental crust, “fairly continuous” and defined. More data had been gathered over the past decades to confirm its existence.

“Like anything in science, the penny doesn’t always drop straightaway. You build up a body of evidence.

“It was all once part of a big continent that’s all broken up into little pieces of the puzzle.”

But despite the evidence in support of it, whether or not Zealandia would come to be widely recognised as the seventh continent was dependant on history, said Mortimer.

“If you want to name a mountain, there are certain procedures you have to go through to get it formally ratified. With this, it will just come with time.

“If Zealandia makes its way into popular culture and onto maps, that’s all the validation that we’ll seek.”</s>Image copyright AFP Image caption Mount Cook, the highest peak of New Zealand - and Zealandia

You think you know your seven continents? Think again, as there's a new contender hoping to join that club.

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.

Image copyright GNS

Some 94% of that area is underwater with only a few islands and three major landmasses sticking out above the surface: New Zealand's North and South Islands and New Caledonia.

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

Image copyright ESA/NASA Image caption New Zealand as captured from space by astronaut Tim Peake

The main author of the article, New Zealand geologist Nick Mortimer, said scientists have been researching data to make the case for Zealandia for more than two decades.

"The scientific value of classifying Zealandia as a continent is much more than just an extra name on a list," the researchers explained.

"That a continent can be so submerged yet unfragmented" makes it useful for "exploring the cohesion and breakup of continental crust".

So how then to get Zealandia into the canon of continents? Should text books authors get nervous again? After all, just a few years ago, Pluto got kicked off the list of planets, changing what had been taught in schools for decades.

There is in fact no scientific body that formally recognises continents. So it could only change over time if future research accepts Zealandia on par with the rest so that eventually we might be learning about eight, not seven, continents.</s>Apparently there’s an eighth continent in the southwest Pacific.

A huge landmass, mostly submerged beneath the ocean, bears all the hallmarks of a continent, according to a new study published by the Geological Society of America. You may have heard of part of it: New Zealand.

They call the continent Zealandia. At nearly 1.9 million square miles, it seems massive, but it’s two thirds the size of the world’s (current) smallest continent, Australia. Ninety-four percent of Zealandia is underwater, with most of the other 6 percent being New Zealand. But it’s what’s beneath the surface that counts, right?

The “Zealandia” moniker was coined by geophysicist Bruce Luyendyk in 1995 (see that famous page turner “Hypothesis for Cretaceous Rifting of East Gondwana Caused By Subducted Slab Capture” for reference.)

Luyendyk argued at the time Zealandia checked three of the four boxes to be considered its own continent. But now geologists say it checks all four: distinctive geology; a finite, defined area; crust thicker than the standard ocean floor; and elevation above the surrounding area. Zealandia apparently has it all.

The experts who penned the study, aptly titled “Zealandia: Earth’s Hidden Continent,” say if Zealandia had been mapped the same way scientists map Venus or Mars with current technology, we would have recognized it as its own continent much earlier.

“The scientific value of classifying Zealandia as a continent is much more than just an extra name on a list,” the authors wrote. They said viewing the landmass as a continent is useful for scientists to explore “the cohesion and breakup of continental crust.”

Unlike with other realms of science (remember how scientists kicked Pluto off the planet list?), there’s no geological scientific body that determines new continents. So for Zealandia to become a continent, the wider scientific community would just have to all go with it.

It may not be a satisfying answer for now, but in geologists’ defense, it was pretty easy to assume we found all of the continents the first time around. As the authors wrote, though, “Zealandia illustrates that the large and the obvious in natural science can be overlooked.”

Beyond the science, it could be a PR win for a small country. The embassy of New Zealand in Washington didn’t immediately respond to Foreign Policy’s request for comment on how they may be sitting on their own continent now.

But others took the news well. “Honestly, it’s about time,” quipped one Kiwi official to FP, who spoke on condition of anonymity. “I had to endure years of taunting from friends that New Zealand wasn’t part of a continent. Look at us now!”</s>CANBERA (dpa-AFX) - Scientists say a huge landmass almost entirely submerged in the southwest Pacific qualifies as a continent, and have made a renewed push for it to be recognized as the eighth continent in the world.



A 4.9 Mkm2 region of the southwest Pacific Ocean, known as Zealandia, 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, researchers said in a paper published in the Geological Society of America's Journal. 



Zealandia was formerly part of Gondwana. Today it is 94 percent 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, says New Zealand geologist Nick Mortimer, the main author of the article.



Copyright RTT News/dpa-AFX</s>Geologists claim to have discovered a new continent to the east of Australia: Zealandia. At 4.9 million square kilometres of land mass, 94 per cent of which is under water, Zealandia would be the world's smallest continent.

The 11 scientists behind the claim presented their findings in the study "Zealandia: Earth's Hidden Continent" in Geological Society of America, making a case for Zealandia to be recognised as the world's eighth continent in its own right.

According to their study, the land mass comprises all the four attributes needed to be considered a continent, including the presence of different rock types and crucially "the high elevation relative to regions floored by oceanic crust."

"It was not a sudden discovery but a gradual realisation," the scientists wrote.</s>Scientists say they have identified a new continent, and called it Zealandia.

In a new paper, a team of 11 geologists have proposed that a region of the Pacific Ocean, located east of Australia and containing New Zealand and New Caledonia, be considered a continent in its own right.

Geographically speaking, there are currently six recognized continents: Africa Antarctica, Australia, Eurasia, North America, and South America. Eurasia is the geographical landmass that includes Europe and Asia.

At 4.9 million square kilometres, Zealandia would be Earth's smallest continent.

It is also the 'youngest, thinnest, and most submerged' of the continents, with 94 percent of the landmass submerged in water, the geologists wrote.

In the paper, titled 'Zealandia: Earth’s Hidden Continent,' the geologists argue that Zealandia has all four attributes necessary to be considered a continent.

Those attributes include 'high elevation relative to regions floored by oceanic crust,' as well as the presence of three types of rocks (igneous, or volcanic; metamorphic, or created by heat and pressure; and sedimentary, or created by erosion).

The other attributes are a thicker, less dense crust than the surrounding ocean floor, and an area large enough to distinguish it from the category of microcontinent.

'The scientific value of classifying Zealandia as a continent is much more than just an extra name on a list,' the scientists wrote.

'That a continent can be so submerged yet unfragmented makes it a useful and thought-provoking geodynamic end member in exploring the cohesion and breakup of continental crust.'

All but one of the 11 researchers behind the paper represent organisations based in New Zealand and New Caledonia. The eleventh scientist is based in Australia.</s>Scientists say they have identified an underwater continent two-thirds the size of Australia — and they are calling it Zealandia.

This newly proposed continent is about 1.74 million square miles in size and 94 percent submerged. But at its highest points, it protrudes above the ocean surface in the form of New Zealand and New Caledonia, according to a paper published in GSA Today, the journal of the Geological Society of America.

The proposed recognition of the continent of Zealandia does not represent the discovery of a new land mass. Rather, the paper argues that the geological evidence suggests the land mass should be classified not as a collection of islands and fragments but as a bona fide continent.

"If we could pull the plug on the oceans, it would be clear to everyone we have mountain chains and a big, high-standing continent above the ocean crust," Nick Mortimer, a geologist at GNS Science in Dunedin, New Zealand, told Reuters.

Mortimer was the lead author of the paper, "Zealandia: Earth's Hidden Continent."

New discoveries about the geology of the region prove what has long been suspected, he said.

"Since about the 1920s, from time to time in geology papers people used the word 'continental' to describe various parts of New Zealand and the Catham Islands and New Caledonia," Mortimer said.

"The difference now is that we feel we've gathered enough information to change 'continental' to the noun 'continent,'" he added.

The land mass meets the geological definition of a continent, according to the paper. It has high elevation compared to the ocean crust. It has certain geological components, including a crust thicker than ocean crust. And it has well-defined limits around an area large enough to be considered a continent rather than a fragment.

Zealandia is believed to have broken away from Australia about 80 million years ago and sunk beneath the sea as part of the break-up of the super-continent Gondwanaland.

By contrast, modern human beings are believed to have emerged only about 200,000 years ago.

Mortimer recognizes that the paper at this point represents the making of a geological case — the opening of an argument rather than its resolution.

"The litmus test will really be if Zealandia appears in maps and atlases in five or 10 years time," he said.</s>We tend to lump New Zealand and Australia together. They’re similar culturally and share the same geographical position, relative to North America and Europe, anyway. But according to a new paper published in the Geological Society of America Today, it looks like New Zealand and their neighbor New Caledonia are actually their own continent: ‘Zealandia.’

Continent means something different to geographers and geologists. To be considered a geological continent, like Zealandia, the area in question has to satisfy a few conditions:
• the land in question has to be higher than the ocean floor
• it has to include a broad range of siliceous igneous, metamorphic, and sedimentary rocks
• it has to have thicker crust than the ocean floor that surrounds it
• it has to have well-defined limits, and be large enough to be considered a continent

In Geology, the first three points are well-understood. But as the authors say in the introduction to their paper, “…the last point—how “major” a piece of continental crust has to be to be called a continent—is almost never discussed… .” Since the Earth has so many micro-continents and continental fragments, defining how large something has to be to be called a continent is challenging. But the researchers did their homework.

They noted that the term “Zealandia” has been used before to describe New Zealand and surrounding regions. But the boundaries were never fully explored. 94% of this new continent is submerged, which helps explain why it’s taken this long to be identified.

Zealandia seemed to be a collection of broken pieces, but new data collected over the years has challenged that interpretation. Recent satellite data has given us new gravity and elevation maps of the seafloor. This data has shown that Zealandia is a unified region large as large as India.

As the authors point out in their paper, it took a while to determine that Zealandia is a continent. There was no Eureka moment. “This is not a sudden discovery but a gradual realization; as recently as 10 years ago we would not have had the accumulated data or confidence in interpretation to write this paper.”

Besides satisfying our intellectual curiosity about our planet, the discovery is important for other reasons. A proper understanding of the plate structures and continental boundaries is important to other sciences, and may trigger further understandings that we can’t predict yet. It may also point to other areas of research.

Also, many treaties rely on the agreed upon delineation of maritime and continental boundaries, including rights to fish stocks and underground resources. While the recognition of Zealandia seems clear from a scientific standpoint, it remains to be seen if it will be accepted politically.</s>According to the Geological Society of America, the landmass is believed to have broken away from Gondwana 60-85 million years ago.

A group of geologists have argued in the March/April 2017 issue of the journal GSA Today that the world has not seven, but eight continents. Zealandia, a mostly submerged landmass located near Australia and partly under New Zealand should be given official recognition as a continent, according to the scientists.

It is “a large enough area to be considered a continent rather than a micro-continent or continental fragment,” the article says. According to the study, Zealandia could have an area of around five million square kilometers (3.1 million square miles). Roughly 94 percent of the area is supposed to be underwater, with only a few islands located at the surface — New Zealand’s North and South islands and New Caledonia.

For it to be classified as a continent it has to meet five criteria, all of which have been fulfilled in this case:

“The scientific value of classifying Zealandia as a continent is much more than just an extra name on a list, that a continent can be so submerged yet unfragmented makes it useful for exploring the cohesion and breakup of continental crust,” the article further says.

Zealandia, which is said to be two-thirds the size of Australia, is assumed to have broken away from the Gondwana landmass, which also comprised of Australia and defragmented 60-85 million years ago.

While it was previously called a micro continent, arguments for it being called a continent are becoming stronger. In 2007, Geologist Dr. Hamish Campbell had argued for the same.

Campbell claimed in his book, "In Search of Ancient New Zealand," published in September 2007, that the sudden awakening and collision of the continental plates about 23 million years ago twisted and deformed the flat Zealandian plains and forced them up and out of the Pacific Ocean.

But, as there is no global scientific authority which identifies and attributes continents, the only way Zealandia becomes a continent would be if future researchers accept the same.</s>New Zealand and Australia might be able to finally give each other more breathing room. It turns out they sit on separate continents. New Zealand calls a 1.8 million square mile land mass known as Zealandia home. This new continent also includes New Caledonia, along with several other territories and island groups.

The idea of a potential continent in this area has been around for some time. Geophysicist Bruce Luyendyk coined the term Zealandia in 1995.

The dedicated study of this area over the past 10 years has determined it is not just a group of continental islands and fragments but that it has a continental crust large and separate enough to be officially declared a separate continent.

Previously, New Zealand and New Caledonia were grouped with Australia under the moniker Australasia.

While most of us would call this the eighth continent, geologists often consider Europe and Asia as one continent called Eurasia. The publication by The Geological Society of America comes barely a week after scientists found a "lost continent" under the Indian Ocean.
Zealandia comes closer to being recognized as a continent.