An international team of geologists believes they have identified a sunken continent hidden under Iceland and the surrounding ocean, which they called Icelandia. The scientists said the continent could stretch from Greenland all the way to Europe. If proven, this new theory will challenge all previous theories around the extent of continental and oceanic crust in the North Atlantic region, as well as contradict the belief that Pangea broken up more than 50 million years ago.
Iceland could be the tip of a massive sunken continent, according to the international team, led by Gillian Foulger, Emeritus Professor of Geophysics in the Department of Earth Sciences at Durham University in the UK, who published their study in GeoScience World.
The landmass is believed to cover an area of around 600 000 km2 (231 600 miles2), but when adjoining areas of Britain are included in a "Greater Icelandia" - the total area could be 1 million km2 (386 000 miles2).
If confirmed, this will contradict the previous theory that the giant supercontinent of Pangea, which is thought to have broken up over 50 million years ago, has not fully broken up.
This new theory also challenges long-held scientific ideas around the extent of continental and oceanic crust in the North Atlantic region, as well as how volcanic islands, like Icelands, formed.
The presence of continental crust, rather than oceanic, could also trigger discussions about a new source of hydrocarbons and minerals, both contained in the continental crust.
"Until now Iceland has puzzled geologists, as existing theories that it is built of and surrounded by oceanic crust are not supported by multiple geological data," said Foulger.
"For example, the crust under Iceland is over 40 km (25 miles) thick-- seven times thicker than normal oceanic crust. This simply could not be explained."
He continued, "However, when we considered the possibility that this thick crust is continental, our data suddenly all made sense. This led us immediately to realize that the continental region was much bigger than Iceland itself—there is a hidden continent right there under the sea."
"There is fantastic work to be done to prove the existence of Icelandia but it also opens up a completely new view of our geological understanding of the world. Something similar could be happening at many more places."
"We could eventually see maps of our oceans and seas being redrawn as our understanding of what lies beneath changes."
The team is now working with collaborators across the world to test their theory, which will commence once the pandemic restrictions ease up.
"Countries around the world are spending enormous resources conducting subsea geologic research in order to identify their continental shelves and claim exclusive mineral rights there," said Professor Philip Steinberg, Director of IBRU, Durham University's Center for Borders Research, who is not involved in the study.
"Research like Professor Foulger's, which forces us to rethink the relationship between the seabed and continental geology, can have far-reaching impact for countries trying to determine what area of the seabed are their exclusive preserve and what areas are to be governed by the International Seabed Authority as the 'common heritage of humankind."
"Icelandia" - Foulger, G. R., et. al. GeoScience World - https://doi.org/10.1130/2021.2553(04)
We propose a new, sunken continent beneath the North Atlantic Ocean that we name Icelandia. It may comprise blocks of full-thickness continental lithosphere or extended, magma-inflated continental layers that form hybrid continental-oceanic lithosphere. It underlies the Greenland-Iceland-Faroe Ridge and the Jan Mayen microplate complex, covering an area of ~600,000 km2. It is contiguous with the Faroe Plateau and known parts of the submarine continental rifted margin offshore Britain. If these are included in a “Greater Icelandia,” the entire area is ~1,000,000 km2 in size. The existence of Icelandia needs to be tested. Candidate approaches include magnetotelluric surveying in Iceland; ultralong, full-crust-penetrating reflection profiling along the length of the Greenland-Iceland-Faroe Ridge; dating zircons collected in Iceland; deep drilling; and reappraisal of the geology of Iceland. Some of these methods could be applied to other candidate sunken continents that are common in the oceans.
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