Scientists discovered long lost sunken island loaded with rare Earth minerals sparking debate over who owns it

An island that used to be roughly the size of Spain has been discovered underneath the sea.

While technically it isn't an island anymore since it has been completely submerged, the seamount holds great geological insight into how our planet used to look a long, long time ago.

For those unfamiliar with the term, a seamount is just an underwater mountain with steep sides rising from the seabed. This particular one has been dubbed Rio Grande Rise, and can be found some 750 miles off the coast of Brazil.

The only difference between this and most other seamounts is they usually were never on the surface - scientists believe it would have once been a luscious tropical island.

Its discovery came over a decade ago, but in 2018 researchers spotted that there were deposits of red clay some 650 meters below the surface (to put that into comparison, the tallest building in the world is the Burj Khalifa at 828 meters) which is not the kind of mineral that you would typically expect to find there.

The once tropical island of Rio Grande Rise sits around 750 miles off the coast of Brazil in the Atlantic Ocean (Google Maps)

Marine geologist Bramley Murton told Eos: "You just don't find red clay on the seabed."

Later research found that the island's origins go back some 80 million years to the Cretaceous Period, when dinosaurs still roamed the Earth.

It was created by a burst of volcanic activity, before drifting westwards and sinking back beneath the ocean, 40 million years later a further eruption led to the deposits which have been found.

These include rich deposits of rare earth minerals such as cobalt, lithium, nickel, and tellurium.

Between them, these elements have a huge variety of industrial applications.

There is an investigation to determine whether Brazil can claim the resources (Researchers’ archive via Agencia FAPESP)

Most notably these include in rechargeable batteries like the ones in computers, electric vehicles, and smart phones.

In other words, it might not be a literal goldmine but it certainly is a figurative one.

This has immediately questions over who has control and ownership over the natural resources at the site.

Brazil has staked a claim, but the problem is that it lies outside of the jurisdiction for it to claim in international waters.

However, there was a way for Brazil to claim the resources, this was to make the case that the area shares geological similarities with the country so is part of Brazil's 'coastal shelf'.

The sunken island is hundreds of miles off the coast of Brazil (Researchers’ archive via Agencia FAPESP)

Luigi Jovane, a professor at the oceanographic institute at the University of São Paulo, said: "Our research and analysis enabled us to determine that it was indeed an island, and what's now under discussion is whether the area can be included in Brazil's legally recognized continental shelf."

Of course, there are also questions about the impact that extracting the minerals would have.

Jovane continued: "To know whether resources can be viably extracted from the sea floor, we need to analyze the sustainability and impacts of this extraction. The ecosystem services provided by the ocean there haven't been studied in detail, for example.

"When you interfere with an area, you have to know how this will affect animals, fungi and corals, and understand the impact you'll have on the cumulative processes involved."