A brand new ocean-mapping expedition is drawing the boundaries of Zealandia, a submerged “misplaced continent” that hosts New Zealand and the territory of New Caledonia within the South Pacific.
Zealandia broke off from the supercontinent Gondwana between 79 million and 83 million years in the past. Apart from New Zealand and New Caledonia, this fragment of continental crust now sits on the ocean flooring. It is not the one little bit of continental crust that is indifferent from a bigger continent, however it’s the largest at 1.9 million sq. miles (four.9 million sq. kilometers). That is six instances bigger than the next-largest continental fragment, the microcontinent of Madagascar.
Zealandia, often known as Te Riu-a-Māui in Māori, was assigned continental status in 2017. Since then, researchers have been working to map the misplaced continent — no simple feat, as 94% of it’s beneath water.
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Now, Derya Gürer, an earth scientist on the College of Queensland in Australia, and her colleagues have collected new information on the northwestern fringe of Zealandia, which is situated offshore in Queensland’s Coral Sea Marine Park. The researchers spent 28 days aboard the vessel Falkor exploring the area, mapping 14,285 sq. miles (37,000 sq. km).
“Our expedition collected seafloor topographic and magnetic information to realize a greater understanding of how the slender connection between the Tasman and Coral Seas within the Cato Trough area — the slender hall between Australia and Zealandia — was fashioned,” Gürer said in a university statement.
The realm between the Australia plate and the Zealandia plate is probably going very sophisticated, Gürer stated. There are in all probability a number of microcontinents submerged there, all of which splintered off the principle continental plenty when Australia broke freed from Gondwana. (The supercontinent encompassed what’s right this moment South America, Africa, Antarctica, Australia, Zealandia, Arabia and the Indian subcontinent.) These fragments of continental crust are completely different from the encompassing oceanic crust of the seafloor, which is denser and thinner than continental crust.
Performed in collaboration with the Schmidt Ocean Institute, the mapping was a part of the Seafloor to Seabirds expedition. The mapping information may also feed into a bigger venture, the Seabed 2030 collaboration, which goals to make a publicly out there, complete map of the ocean flooring by 2030. In accordance with the National Oceanic and Atmospheric Administration (NOAA), lower than 10% of the seafloor has been mapped by trendy sonar strategies, which use sound to disclose undersea topography. The Seafloor to Seabird expedition not solely collected details about topography, but in addition information on the depth of the magnetic discipline throughout the world. As a result of oceanic crust and continental crust are made of various mineral concentrations with completely different magnetic signatures, this information will allow researchers to reconstruct the damaged fragments of Gondwana.
“The seafloor is stuffed with clues for understanding the advanced geologic historical past of each the Australian and Zealandian continental plates,” Gürer stated.
Initially printed on Dwell Science.