Mapping Zealandia: Scientists are exploring the seafloor off the coast of Australia in hopes of unraveling the mystery of Earth’s eighth ‘hidden’ continent that sank into the sea 23 million years ago
- The ‘lost’ continent of Zealandia was first identified by geologists in 2014
- Australian and American experts charted the depths of northwestern Zealandia
- The team collected 4,286 square miles of bathymetric data in total
- It will be used by the Seabed 2030 project to build a map of the world’s oceans.
Scientists have been exploring the seafloor off Australia to unravel the mystery of Zealandia, the eighth “lost” continent that sank into the sea 23 million years ago.
The mostly submerged continent, of which New Zealand and New Caledonia remain above the waves, was first identified by geologists in 2014.
Australian and American experts have just spent 28 days at sea on the Falkor research ship that maps the depth of the seafloor off the northwestern edge of Zealandia.
They collected 14,286 square miles (37,000 square kilometers) of bathymetric data that they have provided to the Seabed 2030 project.
This effort aims to produce a publicly available bathymetric map of the world’s ocean floor by 2030.
Scientists have been exploring the seafloor off Australia to unravel the mystery of Zealandia (pictured), the eighth ‘lost’ continent that sank into the sea 23 million years ago.
Australian and American experts have just spent 28 days at sea on the research ship Falkor (pictured, with expedition leader Derya Gürer in the foreground) mapping the depth of the ocean floor in the extreme northwest of Zealandia, in the Coral Sea Marine Park.
“We are just beginning to uncover the secrets of Zealandia; it remained hidden in plain sight until recently and is very difficult to study,” said expedition leader and geologist Derya Gürer of the University of Queensland.
“Zealandia is an almost completely submerged mass of continental crust that sank after separating from Gondwanaland 83 to 79 million years ago.”
Gondwanaland is the name given to the supercontinent that included land masses that we would recognize as South America, Africa, and Antarctica.
It formed around 550 million years ago before becoming part of the larger Pangea supercontinent and dissolved starting around 180 million years ago.
Zealandia, Dr. Gürer continued, ‘spans 4.9 million square kilometers [1.9 million square miles] and it’s about three times the size of Queensland. “
“ Our expedition collected seafloor topographic and magnetic data to better understand how the close connection between the Tasman and Coral Seas was formed in the Cato Trough region, the corridor between Australia and Zealandia. ”
“The seabed is full of clues to understanding the complex geological history of the continental plates of Australia and Zealand.”
“These data will also improve our understanding of the complex structure of the crust between the Australian and Zealand plates.”
“It is believed to include several small continental fragments, or microcontinents, that separated from Australia and the supercontinent Gondwana in the past.”
The mostly submerged continent, of which New Zealand and New Caledonia remain above the waves, was first identified by geologists in 2014. In the image, a tectonic map of the 1,930,511-square-mile continent of Zealandia, only a small part of the which outcrops on the ground. On the map, the continental crust is shown in shades of red, orange, yellow, and brown, while the oceanic crust is shaded in blue. The arc crust of the volcanic island is pink, while the great igneous provinces are green
While conducting their bathymetric study at Coral Sea Marine Park, the researchers also took the opportunity to study seabirds and also monitor ocean-borne microplastic pollution. In the picture: the researchers took samples of microplastics in the wet laboratory
While conducting their bathymetric study at Coral Sea Marine Park, the researchers also took the opportunity to study seabirds and also monitor ocean-borne microplastic pollution.
“Through the ship’s ongoing seawater flow system, we analyzed more than 100 microplastic samples, in addition to 40 samples collected from a previous voyage,” said earth scientist Tara Jonell, also from the University of Queensland. .
“Only one sample did not contain any visible microplastics,” he added.
According to Dr. Gürer, who is also involved in a citizen science project to address marine plastic pollution, there was a clear message in the seawater, which was collected at depths of up to 2.2 miles (3.5 kilometers) .
“There appears to be a higher concentration of microplastic fibers in the deep ocean,” he explained.
ZEALAND: EARTH’S ‘LOST’ EIGHTH CONTINENT
In the photo, the continent of Zealandia
‘Zealandia’, also known as ‘Te Riu-a-Māui’ in te reo Māori, is a largely submerged mass of continental crust.
Zealandia sank when it broke away from the supercontinent of Gondwanaland about 83-79 million years ago.
The concept of Zealandia was first proposed in 1995, but it was only recognized as a continent in its own right in 2017.
It is twice the size of the largest microcontinent and also meets continental criteria for crust thickness and density.