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2 months ago
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Scientists have discovered a lost continent deep within the southern arm of the Artic Ocean, which formed 60 million years ago.
Researchers at the UK's University of Derby accidently uncovered the 250-mile-long landmass below the Davis Strait, between Canada and Greenland, while studying the area's plate tectonic movements.
The newly found Davis Strait proto-microcontinent, a tectonic block that became detached from a continent, was created through 'a prolonged period of rifting and seafloor spreading between Greenland and North America,' researchers explained.
The team suggested the proto-microcontinent separated from Greenland after the tectonics between the country and Canada split in two about 118 million years ago.
Scientists discovered a submerged microcontinent in between Canada and Greenland that formed 60 million years ago. Pictured: The Davis Strait where the microcontinent was discovered
Researchers at the University of Derby were reconstructing the area's plate tectonic movements when they found a thick crust that extended for nearly 250 miles under the Davis Strait. Pictured: The Davis Strait Proto-microcontinent sits beneath the water in the Davis Strait
'Rifting and microcontinent formation are absolutely ongoing phenomena—with every earthquake we might be working towards the next microcontinent separation,' Dr Jordan Phethean told Phys.org.
'The aim of our work is to understand their formation well enough to predict that very future evolution.'
Researchers identified the new microcontinent using a combination of crustal thickness data from from gravity maps, seismic reflection data, and plate tectonic modeling.
Gravity maps contains information about rock density, and depth and distribution of anomaly source rocks.
The team focused on how the crustal anomaly formed by generating a reconstruction of the tectonic movements that lasted for roughly 30 million years.
They described the proto-microcontinent as being bigger than other microcontinents, amounting to between 11 and 14 miles thick, and said that understanding how it formed is vital for ongoing science today.
The average microcontinent is typically between three and 15 miles thick.
The mapping techniques tracked how the seafloor's movements had changed over millions of years and identified 'an isolated terrane of relatively thick continental crust that was separated from Greenland during a newly recognized phase of [the east to west] extension along West Greenland,' according to the study.
Researchers said the Davis Strait is one of the largest concentration of known fault structures with well-defined changes in plate motion that could help understand how microcontinents form.
Proto-microcontinents are are part of the continental lithosphere, which is a section of the Earth's outer crust that is divided into several tectonic plates - slabs of rock.
There is a semi-fluid layer of rock located about 50 to 120 miles below the Earth's surface that is heated and subsequently melted, causing the rock to flow.
The motion pushes along the tectonic plates, causing them to rub against each other over millions of years and resulting in earthquakes and volcanic explosions.
When this happens, the land mass will separate from major continents, creating its own proto-microcontinent.
Proto-microcontinents are are part of the continental lithosphere which is a section of the Earth's outer crust that is divided into several tectonic plates - slabs of rock. Pictured: Tectonic plates shifting over millions of years
The research team used maps that were created from gravity and seismic reflection data that display images of the Earth's subsurface using sound waves determine the fault lines' age and location. Pictured: An overview of the tectonic plates located in the Davis Strait
Initial rifting between Canada and Greenland started about 118 million years ago, but the seafloor didn't start to spread until 61 million years ago to create what's today known as the Davis Strait.
After about three million years, scientists reported that the seafloor spreading shifted from northeast-southwest to north-south, which broke off the Davis Straight proto-microcontinent.
The shift lasted for roughly 33 million years and only stopped when Greenland collided with Ellesmere Island which is located to the north.
The researchers said they hope their findings can be used to understand how other proto-microcontinents form around the world including the Jan Mayen microcontinent to the northeast of Iceland and the Gulden Draak Knoll off the coast of Western Australia.
'Rifting and microcontinent formation are absolutely ongoing phenomena—with every earthquake we might be working towards the next microcontinent separation,' Phethean told Phys.org.
'The aim of our work is to understand their formation well enough to predict that very future evolution.'
