Evidence of Zealandia

Aliki Weststrate provides some background information about the formation of Zealandia, a continent created by tectonic movement 80 million years ago.

Point of interest: Aliki refers to Zealandia as the seventh continent. Depending on the definition used, there are five to eight continents on Earth.

Note: The video is part of a ship to shore Skype interview with Otumoetai Intermediate School. The video footage was bounced off a satellite, which affects the sound and picture quality.

Transcript

ALIKI WESTSTRATE

Zealandia kind of broke away from Australia and Antarctica. There was a whole lot of volcanic activity 80 million years ago in the Pacific Ring of Fire. We are not really sure what triggered it, but Zealandia did start drifting away and is actually considered a seventh continent now, so it’s quite cool for New Zealand because New Zealand is the bit that is sticking up – 94% of Zealandia is underwater. 

They took the JOIDES to drill in different parts of Zealandia. And what they found was the rock and the sediment is actually the same type of rock and sediment that they are finding on the Alpine Fault. So they have pieced this puzzle together, and they have realised that Zealandia, although it’s quite a big area and it’s a strange shape, it actually formed about the same time. It used to be a lot shallower, a lot of it used to be above land. And they have found plants and sealife, which has been turned into fossilised remains as it’s been buried in the sediments. They have found that and they have been able to date it and work out that it all comes from around the same time.
 
They have mapped the seafloor to some degree but they need to map it a whole lot more and they need to drill a whole lot more to find out more about Zealandia.

Acknowledgements
Aliki Weststrate
International Ocean Discovery Program (IODP)
Australia and New Zealand International Ocean Discovery Program Consortium (ANZIC)
GNS Science
Otumoetai Intermediate School
 
JOIDES Resolution sail-by by ZCENE Moving Media for IODP courtesy of Ocean Leadership, IODP and ZCENE
 
On-deck coring footage and animated globe with Zealandia appearing by Thanos Fatouros for IODP courtesy of Thanos Fatouros, US Science Support Program and IODP
 
Footage of core lab and close-ups of cores from expedition #371 by Adam Kurtz for IODP courtesy of Adam Kurtz, US Science Support Program and IODP
 
Alpine Fault rock micrographs, Dr Virginia Toy, University of Otago
 
Metamorphic rock zones map and B&W schematic showing alpine rock types all courtesy of Professor David Prior, University of Otago
 
All other footage from ship to shore video conference from JOIDES Resolution expedition #375 courtesy of Otumoetai Intermediate School