Concealed beneath the pristine waters of the South Pacific Ocean, a stunning geological wonder awaits – a submerged continent known as Zealandia or Te Riu-a-Maui in the Maori language.
This enigmatic landmass has remained a well-guarded secret, but in recent years, scientific expeditions have finally unveiled its mysteries. Join us on a thrilling journey as we explore the captivating world of Zealandia, a micro-continent that was lost in the depths of the ocean for 375 years.
All you need to know about Zealandia – Earth’s 8th Continent
Approximately 83 million years ago, Earth’s geological forces orchestrated the breakup of the supercontinent Gondwana, giving birth to Zealandia.
This submerged continent, now concealed beneath the ocean’s depths, accounts for 94 percent of its expanse. Only 6 percent emerge above the waves, comprising New Zealand, New Caledonia, and neighbouring isles.
“This is an example of how something very obvious can take a while to uncover,” said Andy Tulloch, a geologist at the New Zealand Crown Research Institute GNS Science, who was part of the team that discovered Zealandia, as quoted by a BBC report.
A historical odyssey
Zealandia, an intriguing microcontinent located to the east of Australia, boasts an extensive landmass spanning roughly 4.9 million square kilometres – approximately six times the size of Madagascar, according to BBC. Its unveiling began with Abel Tasman’s initial discovery of New Zealand in 1642. The first tangible clues regarding Zealandia’s existence came to light with the pioneering work of Scottish naturalist Sir James Hector during an expedition in 1895, which focused on studying a string of islands off the southern coast of New Zealand.
Nevertheless, even with this initial milestone, Zealandia’s understanding lay mostly in the shadows, with minimal progress until the 1960s. “Things happen pretty slowly in this field,” says Nick Mortimer, a geologist at GNS Science, who led the 2017 study.
A consensus on the specific criteria that define a continent emerged. In essence, a continent came to be recognised as a geological region distinguished by notable elevation, a wealth of diverse rock formations, a substantial crust, and notably, a significant expanse of land.
The birth of Zealandia
In 1995, American geophysicist Bruce Luyendyk officially designated this landmass as a continent, bestowing upon it the name “Zealandia”.
Around the same time, the “United Nations Convention on the Law of the Sea” extended nations’ territorial rights to stretch their legal boundaries beyond the familiar 200-nautical-mile (370 km) limit of their Exclusive Economic Zones, spurring exploration. Cutting-edge satellite data analysis, which tracked Earth’s gravitational field changes, unlocked the secrets of the ocean floor.
The ‘ancient’ roots of Zealandia
The tale of Zealandia goes back to the ancient days of the supercontinent Gondwana, which formed approximately 550 million years ago, uniting the vast southern hemisphere. Within Gondwana, Zealandia found its place along the eastern border, nestled beside a collection of neighbouring landmasses. These included a substantial portion of West Antarctica and the entire eastern stretch of Australia, creating a travel-worthy mosaic of history waiting for travellers to explore.
The gradual disintegration of Gondwana spanned an astounding 130 million years, scattering its pieces across the globe like a grand puzzle. These fractured fragments became the building blocks for the continents we know today, such as South America, Africa, Madagascar, Antarctica, Australia, the Arabian Peninsula, the Indian Subcontinent, and, notably, Zealandia.
This tells us that a part of Zealandia has enjoyed dry land throughout its geological past. Nevertheless, around 25 million years ago, evidence hints at a dramatic shift: the entire continent, possibly including all of New Zealand, found itself entirely submerged beneath the ocean’s depths. Normally, continental crust has a thickness of approximately 40 kilometres. However, Zealandia experienced extensive stretching, causing its crust to slim down to a mere 20 kilometres, and ultimately disappearing beneath the waves of the ocean.
Even though it’s mostly underwater, Zealandia has earned its title as a continent based on the distinctive rock composition found within its boundaries. Continents typically showcase a diverse array of rock types, including igneous, metamorphic, and sedimentary varieties like granite, schist, and limestone. This stands in stark contrast to the ocean floor, predominantly composed of igneous rocks like basalt.
Unearthing Zealandia’s mysteries
Unearthing the hidden wonders of Zealandia poses a remarkable challenge, as it lies submerged at depths of approximately 1.2 miles (2 kilometres), with crucial layers buried beneath 500 metres (1,640 feet) of seabed. Yet, above all, the emergence of the world’s eighth continent highlights the enduring allure of exploration and the thrill of discovery. It stands as a testament that, nearly four centuries after Tasman’s groundbreaking voyage in 1642, Zealandia’s history has remained an enigmatic tale, poised for a new era of exploration.
(Hero and feature image credit: ETOPO2v2, CC0 1.0, via Wikimedia Commons)
FAQs (Frequently Asked Questions)
– What is Zealandia?
Zealandia is a microcontinent submerged under the South Pacific Ocean with an estimated 94 percent of its expanse submerged beneath the ocean, leaving just 6 percent of land territories.
– How big is Zealandia?
The landmass covers approximately 4.9 million square kilometres, which is approximately six times the size of Madagascar.
– What countries are part of Zealandia?
The Islands of New Zealand and New Caledonia are a part of Zealandia.
– Can I visit Zealandia as a tourist?
Yes, you can visit Zealandia as a tourist. Guided day and night tours are provided for all visitors. Tourists can also opt for exclusive and private tours.
– What geological features can be found in Zealandia?
The Islands of New Zealand, New Caledonia and the Ball’s Pyramid, an ancient volcanic stack, provide us with a glimpse of Zealandia’s geological features.
– Is Zealandia important for environmental conservation?
The discovery of this microcontinent helps provide an in-depth insight into the geographical evolution of land masses which has taken place over millions of years.
– How can I learn more about Zealandia?
You can get more information from research papers, and articles written with verified information on the now-sunken continent.