It took scientists 375 years to discover the eighth continent of the world, which has been hiding in plain sight all along. But mysteries still remain.
It was 1642 and Abel Tasman was on a mission. The experienced Dutch sailor, who sported a flamboyant moustache, bushy goatee and penchant for rough justice – he later tried to hang some of his crew on a drunken whim – was confident of the existence of a vast continent in the southern hemisphere, and determined to find it.
At the time, this portion of the globe was still largely mysterious to Europeans, but they had an unshakeable belief that there must be a large land mass there – pre-emptively named Terra Australis – to balance out their own continent in the North. The fixation dated back to Ancient Roman times, but only now was it going to be tested.
And so, on 14 August, Tasman set sail from his company’s base in Jakarta, Indonesia, with two small ships and headed west, then south, then east, eventually ending up at the South Island of New Zealand. His first encounter with the local Māori people did not go well: on day two, several paddled out on a canoe, and rammed a small boat that was passing messages between the Dutch ships. Four Europeans died. Later, the Europeans fired a cannon at 11 more canoes – it’s not known what happened to their targets.
And that was the end of his mission – Tasman named the fateful location Moordenaers (Murderers) Bay, with little sense of irony, and sailed home several weeks later without even having set foot on this new land. While he believed that he had indeed discovered the great southern continent, evidently, it was hardly the commercial utopia he had envisaged. He did not return.
(By this time, Australia was already known about, but the Europeans thought it was not the legendary continent they were looking for. Later, it was named after Terra Australis when they changed their minds).
Little did Tasman know, he was right all along. There was a missing continent.
In 2017, a group of geologists hit the headlines when they announced their discovery of Zealandia –Te Riu-a-Māui in the Māori language. A vast continent of 1.89 million sq miles (4.9 million sq km) it is around six times the size of Madagascar.
Though the world’s encyclopaedias, maps and search engines had been adamant that there are just seven continents for some time, the team confidently informed the world that this was wrong. There are eight after all – and the latest addition breaks all the records, as the smallest, thinnest, and youngest in the world. The catch is that 94% of it is underwater, with just a handful of islands, such as New Zealand, thrusting out from its oceanic depths. It had been hiding in plain sight all along.
“This is an example of how something very obvious can take a while to uncover,” says Andy Tulloch, a geologist at the New Zealand Crown Research Institute GNS Science, who was part of the team that discovered Zealandia.
But this is just the beginning. Four years on and the continent is as enigmatic as ever, its secrets jealously guarded beneath 6,560 ft (2km) of water. How was it formed? What used to live there? And how long has it been underwater?
A laborious discovery
In fact, Zealandia has always been difficult to study.
More than a century after Tasman discovered New Zealand in 1642, the British map-maker James Cook was sent on a scientific voyage to the southern hemisphere. His official instructions were to observe the passing of Venus between the Earth and the Sun, in order to calculate how far away the Sun is.
But he also carried with him a sealed envelope, which he was instructed to open when he had completed the first task. This contained a top-secret mission to discover the southern continent – which he arguably sailed straight over, before reaching New Zealand.
The first real clues of Zealandia’s existence were gathered by the Scottish naturalist Sir James Hector, who attended a voyage to survey a series of islands off the southern coast of New Zealand in 1895. After studying their geology, he concluded that New Zealand is “the remnant of a mountain-chain that formed the crest of a great continental area that stretched far to the south and east, and which is now submerged…”.
Despite this early breakthrough, the knowledge of a possible Zealandia remained obscure, and very little happened until the 1960s. “Things happen pretty slowly in this field,” says Nick Mortimer, a geologist at GNS Science who led the 2017 study.
Then in the 1960s, geologists finally agreed on a definition of what a continent is – broadly, a geological area with a high elevation, wide variety of rocks, and a thick crust. It also has to be big. “You just can’t be a tiny piece,” says Mortimer. This gave geologists something to work with – if they could collect the evidence, they could prove that the eighth continent was real.