An island resurfaces from the Atlantic after being submerged for 40 million years, sparking a nation's ambition to lay claim to it.
In the depths of the South Atlantic ocean, a significant discovery has been made: the remains of a massive tropical island that stood above sea level over 40 million years ago, now known as the Rio Grande Rise. This underwater feature, under the jurisdiction of the International Seabed Authority (ISA), is believed to be rich in tellurium, nickel, cobalt, and especially lithium - minerals critical for building batteries and other green energy technologies [1].
Brazil has formally submitted a claim to extend its continental shelf to include the Rio Grande Rise, aiming to claim sovereign rights over the seabed and its vast mineral reserves. The country's claim depends on proving it is a natural extension of Brazil's continental shelf, as permitted under the United Nations Convention on the Law of the Sea (UNCLOS). The ISA oversees mining in these international waters and requires that environmental impact studies be conducted to ensure sustainable extraction [1].
The discovery was made by a team of geologists from the University of São Paulo and the National Oceanography Centre during deep-sea missions aboard the RRS Discovery and Alpha Crucis. Unusual bands of red clay, a soil type typically formed in humid, tropical conditions, were found sandwiched between hardened lava flows on the seafloor. The presence of foraminifera, volcanic ash, and marine sediment atop the red clay indicates its final burial under the sea, dating from the late Eocene to early Oligocene [1].
The layered lava flows interspersed with weathered soil suggest that volcanic eruptions were not continuous but occurred in phases, giving way to long periods of erosion and soil formation. The mineral and magnetic data confirm that the island underwent a complete transformation from an exposed, weather-beaten landmass to a submerged plateau shaped by tectonic subsidence [1].
Brazil's move highlights growing interest among nations in exploiting seabed mineral resources outside national jurisdictions. It also underscores the need for stringent environmental regulation and impact assessments due to fragile deep-sea ecosystems. Marine biologists and geologists warn that rushing into extraction could disturb ecosystems we've barely begun to understand [1].
The case tests UNCLOS and ISA frameworks on continental shelf extensions and seabed mining rights, emphasizing the delicate balance between sovereign claims and protection of international commons. The future of the Rio Grande Rise now sits at the intersection of scientific research, resource extraction, and international law [1].
If granted exclusive access, Brazil could become a central player in the global green energy supply chain, controlling one of the few known undersea regions with large lithium deposits. However, Brazil currently lags in rare earths processing capacity [1][2][5].
In summary, Brazil’s claim over the Rio Grande Rise is at an active stage within ISA's legal and environmental review processes, with significant potential to influence deep-sea mining governance and international seabed resource exploitation policies.
[1] - https://www.nature.com/articles/s41598-021-92409-w [2] - https://www.bbc.com/news/science-environment-56989269 [3] - https://www.sciencedirect.com/science/article/pii/S0016703719309122 [4] - https://www.sciencedirect.com/science/article/pii/S0045782518300490 [5] - https://www.sciencedirect.com/science/article/pii/S0301421520302640
