Zealandia the eighth continent of planet Earth seems set to upset a whole variety of scientific applecarts. Last week’s blog introduced the new continent, and discussed the ground work that resulted in its “discovery”. It is still amazing to me that it was missed for so long. It’s not as if it’s tiny, 1.9 million square miles is a significant chunk of real estate. However, miss it we did, and now we have a whole new world to investigate, albeit two kilometres underwater.
How was it formed? What used to live there? And how long has it been underwater? These are but a few of the initial questions that will take years, and a fortune in resources, to answer. However, it’s exciting. Almost as exciting as “Perseverance” landing on Mars this week. The old adage appears to be true. We know more about the Moon, and now Mars, than we do about what’s under our ocean depths. The New Zealand geologists, who confirmed Zealandia’s existence four years ago, must have felt a bit like Christopher Columbus, although they, at least, knew where what they found was, and they got the name right!
The final evidence that clinched Zealandia’s reality was obtained from satellite data. That data uses tiny variations in Earth’s gravity as a way of mapping the ocean floor. Zealandia emerged as a misshapen mass almost as large as Australia.
The fact that it’s misshapen, is yet another mystery. It appears to be long, and relatively narrow, but twisted and bent in the middle. No-one has the faintest idea how that could have happened, or why it didn’t break up into smaller pieces.
Zealandia was originally part of the ancient super-continent of Gondwana, which was formed 550 million years ago. When Gondwana started to break up, it formed South America, Africa, Madagascar, Antartica, Australia, the Arabian Peninsula, the Indian Sub-continent and Zealandia.
Gondwana had a mild climate, and a size bordering on 39 million square miles. It was home to a vast array of flora and fauna, including the first four-limbed land animals. It was also home to the largest animals that ever lived, the titanosaurs. It is logical to assume that Zealandia inherited many of these species.
Next week’s continuing blog explores what might have caused Zealandia to sink, and what species it might have inherited from Gondwana.
As you can gather, I find this amazing revelation of an eighth continent totally intriguing.