Zealandia: The Lost Continent That Sank Beneath New Zealand

Published December 18, 2018
Updated April 5, 2019
Published December 18, 2018
Updated April 5, 2019

A 2017 expedition claims to have definitive evidence of a new continent about as big as India. And the discovery of Zealandia could have international economic implications.

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N. Mortimer et al./GSA TodayMap of Earth’s continents including Zealandia.

Everyone knows the story of Atlantis. But while Atlantis is a myth, sunken landmasses are certainly real — and none are more fascinating than that landmass lurking beneath New Zealand: Zealandia.

The First Discovery Of Zealandia

Zealandia is a submerged continent buried deep beneath the waves of the Pacific. And it’s not uninhabited.

That’s because roughly six percent of the landmass’s nearly two million square miles are still above sea level as New Zealand and its outlying islands. These are the highest points of what was once a much larger expanse of land.

Zealandia Topography

Wikimedia CommonsA topographical map of Zealandia, with New Zealand showing as the major landform. The east coast of Australia is on the left.

As a result, Zealandia wasn’t so much discovered as recognized. In 1995, an American geophysicist and oceanographer named Bruce Luyendyk was studying Gondwana, which was a piece of the supercontinent Pangaea that geologists think split apart around 180 million years ago to give us present-day South America, Africa, India, Australia, and Antarctica.

Luyendyk had started this research back in the 80s when he attempted to match the Antarctic geologic features to the edges of New Zealand — a project akin to trying to fit pieces of a crumbling puzzle back together.

The work led him and his fellow researchers to take a closer look at the seabed around New Zealand, and what they found astonished them: the rock beneath the island nation might constitute a continent in its own right.

What Makes A Continent?

Lost Continent Of Zealandia

Wikimedia CommonsA map of Zealandia, outlining important points. New Caledonia is to the north. The Tasman Sea is to the west.

Most learn in school that there are seven continents, but geologists have posited that there are but six as Europe and Asia can be considered a single continent. Whether Zealandia is considered the seventh or the eighth continent, then, may be up for debate but geologists argue that it is regardless a continent in its own right.

That is in part because the rock beneath New Zealand, by Luyendyk’s calculations, meets the criteria which classify a landmass as a continent. Luyendyk called the area Zealandia when he recognized that New Zealand and its outlying islands weren’t actually disparate, and it wasn’t long before other researchers took up the cause and pointed to all the qualities that made Zealandia fundamentally the same as other continents — just under water.

For one, Zealandia is raised above the ocean floor — there’s a clear difference between the submerged landmass and the surrounding seabed, and not just in their respective heights. Zealandia, unlike the neighboring ocean floor, is made from the bulkier, less dense material that forms the continental crust.

Its composition, too, meets the requirements. Like other continents, it is made up of three separate types of rock: igneous, metamorphic, and sedimentary. This variety reveals that it was formed and shaped by volcanic activity, heat and pressure, and erosion — just like its fellow continents.

Ball's Pyramid

Wikimedia CommonsBall’s Pyramid, a dramatic reminder of Zealandia’s volcanic-formed landscape.

It’s also big — too big to be just a continental fragment. Though some have argued that Zealandia better deserves the less impressive designation “microcontinent,” many have pushed back, pointing out that the rock beneath New Zealand is significantly larger than even the largest recognized microcontinent.

Though Zealandia is nearly two-thirds of the size of Australia, the landmass is still considered by some researchers to be more comparable to a continent than anything else.

Whether Zealandia constitutes a continent or not can seem like a rather dry technical point for scientists to argue over. But the answer has real consequences for the region economically.

The United Nations determines a country’s right to drill off-shore based on continental boundaries — and if the entire landmass of Zealandia belongs to New Zealand, that significantly changes the island nation’s fortunes.

By some estimates, tens of billions of dollars worth of fossil fuels would suddenly become available to the country if Zealandia were recognized.

Atlas Pro explains what makes a continent and why the history of the underwater Zealandia makes it a candidate.

Piecing Together Zealandia’s History

Few teams have done more to asser that Zealandia is a continent than the expedition that set out to drill into Zealandia’s submerged rock in 2017.

The project was a tricky one, as the lost continent is hidden beneath two-thirds of a mile of water, and to get a range of samples, the researchers had to drill 4,000 feet into the sediment over a period of nine weeks.

But their efforts proved fruitful. Geologists believed that Zealandia separated from Antarctica somewhere between 85 and 130 million years ago, then broke off from Australia between 60 and 85 million years ago.

Watch Pangaea split apart to form the continents we recognize today — and Zealandia.

This research confirms that notion and further posited that as Zealandia separated from Australia, its crust stretched and thinned until it dropped to the bottom of the ocean.

No human ever saw the continent above the water — and some have doubted whether it stayed on the surface long enough for any animals to inhabit it either, but the researchers were able to find hundreds of fossils, crushed shells, and pollen samples which suggest that the continent spent more time than scientists previously thought at a relatively shallow depth — meaning that for a time, animals easily crossed between the continent’s highest points and plants covered its tropical peaks.

Shells

Wikimedia Commons Fossils of tiny shells.

The news is a critical piece in several ongoing puzzles.

First, the discovery that the region’s climate was once tropical offers scientists new climate data that doesn’t just help them understand the past but it also makes them better able to predict climate shifts in the future.

The discovery also answers longstanding questions about how the region’s animals evolved and spread from continent to continent, and it paints a fascinating new picture of Zealandia as a verdant jungle teeming with life — a jungle that’s now at the bottom of the ocean.


After this look at the lost continent of Zealandia, read up on the Bimini Road in the Bahamas. Or take a look at Lemuria, another lost continent south of India.

William DeLong
William DeLong is a freelance wordsmith. He thanks you for reading his content.