ZELANDIAZELANDIA

6th September, 2023 Geography

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Context

Scientists have finally confirmed the existence of a "missing" continent known as Zealandia.

About Zealandia

Zealandia, which covers around 1.89 million square miles, was formerly a component of the ancient supercontinent Gondwana.
Over 500 million years ago, it also comprised Western Antarctica and Eastern Australia.
Zealandia, on the other hand, began to "pull away" from Gondwana around 105 million years ago.
Essentially, Zealandia's southern part (on the Pacific Plate) began to shift relative to the northern part (on the Indo-Australian Plate). Geological maps show the consequent displacement of approximately 500 kilometers along the Alpine Fault.
It steadily fell beneath the seas as it did so, with over 94% of the continent lying underwater for millennia.
It is roughly 1.89 million square miles (4.9 million square kilometers) in area, or roughly half the size of Australia.
The great part of this new continent is submerged beneath 6,560 feet (2 kilometers) of water.
The above-water portion of Zealandia serves as the basis for New Zealand's north and south islands, as well as the island of New Caledonia.
Zealandia is located on the boundary of many tectonic plates, including the Australian Plate, Pacific Plate, and Indo-Australian Plate.
Abel Tasman, a Dutch businessman and sailor on a journey to find the "great Southern Continent," or Terra Australis, discovered Zealandia in 1642.

Status in present day

Zealandia is now called as the world’s 8^th
Zealandia has only three continents. New Zealand has the most land above sea level in Zealandia, followed by New Caledonia.
94% of it is still submerged underneath the Pacific Ocean.
Zealandia has gas fields, the largest of which being the New Zealand Maui gas field near Taranaki.

More Information on Zealandia

Geology

The Zealandia continent is largely made up of two nearly parallel ridges, separated by a failed rift, where the rift breakup of the continent stops and becomes a filled graben.
The ridges rise above the sea floor to heights of 1,000–1,500 m (3,300–4,900 ft), with a few rocky islands rising above sea level.
The ridges are continental rock, but are lower in elevation than normal continents because their crust is thinner than usual, approximately 20 km thick, and consequently, they do not float so high above Earth's mantle as that of most landmasses.

Volcanism

Volcanoes erupted in diverse locations of Zealandia before, during, and after the continental fragment rifted away from the supercontinent Gondwana.

Geological subdivisions

Occasionally, Zealandia is divided into two regions by scientists, North Zealandia (or Western Province) and South Zealandia (or Eastern Province), the latter of which contains most of the Median Batholith crust.
These two features are separated by the Alpine Fault and Kermadec Trench and by the wedge-shaped Hikurangi Plateau, and they are moving separately to each other.

Tectonics

The breakup of Gondwana formed Northern Zealandia. Zealandia underwent extension resulting from east to northeast-directed rollback of west to southwest-dipping seductions of the Pacific Plate, Which terminated between 95 million to 85 million years ago.
After 85 million years ago Zealandia separated from Australia through seafloor spreading of the Coral and Tasman seas until this ceased 52 million years ago.

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