Scientists Have Created the Most Precise Map Yet of Zealandia — the Sunken 8th Continent That Never Was

Just when we thought we’d overcome this childhood grief, another surprise waits for us. What if we told you that, contrary to what you might've been taught, there are actually eight continents out there?

As usual, there's an asterisk attached to this, too. The term 'continent' does not have a particularly universal connotation. For example, while Indians believe in the seven-continent model, Russians swear by six, forcing Europe and Asia to band together. In fact, even the Olympics follow a separate model, with its five rings coloured after five continents, combining the Americas and excluding Antarctica.

However, things become simpler (and maybe a tinge more complicated) when you examine continents from a geological lens. While geological continents do correspond to the seven massive areas of continental crust on the tectonic plates, the Earth also hosts a myriad of much smaller chunks of crust, what geologists generally consider a 'microcontinent'.

Now, prepare for a Pluto-sized flashback. Approximately 23 million years ago, most of the landmass of one of these microcontinents called Zealandia, retreated into the Pacific Ocean, leaving only 6% above water — what we now know as New Zealand and a few neighbouring island countries. However, even while being six times the size of the next-largest microcontinent, it has to share the same title.

A total area of approximately 4.9 million square kilometres means that Zealandia is half the size of Australia, twice as big as Greenland, and more colossal than the Indian subcontinent. Even as many passionate geologists rally that it fulfils all the criteria to be considered a full-blown continent, it doesn't even get a meagre 'sub' in the name.

However, newly dredged rock samples recovered from the ocean floor in the area have helped with just that, producing the most precise map of the microcontinent yet!

Most of the boundary efforts include examining rock and sediment samples, mostly from drilling sites in the area. In addition, studying seismic and magnetic data helps discover anomalies in the region, distinguishing geological features such as subduction zones and slips, which help establish clearer tectonic boundaries.

All evidence considered, scientists reckon that the region's famous and baffling magnetic aberrations (termed the Campbell Magnetic Anomaly) were probably created when Gondwana — an ancient supercontinent comprising a bunch of continents including India and Zealandia — was being torn apart. This eventually created the ocean floor Zealandia stands on.

The findings of this study have been published in Tectonics and can be accessed here.

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