Iatá-Piuna Expedition to the Rio Grande Rise

Iatá-Piuna means “Navigating in Deep and Dark Waters” in the Tupi-Guarani native indian language. That is the name of the expedition that recently explored the Rio Grande Rise and adjacent areas almost 1,500km from the coast of Rio de Janeiro in the Mid-Atlantic Ocean. The Iatá-Piuna expedition is a partnership between Brazil and Japan to explore what researchers believe is a continental mass that sank around 100 million years ago, during the break-up of Gondwana.

Since 1985 there is a Technical and Scientific agreement between the Brazilian and Japanese governments and this latest expedition happened through an agreement between the Oceanographic Institute of the University of São Paulo (IOUSP), the Brazilian Geological Service (CPRM), and the Japan Agency for Marine-Earth Science and Technology (Jamstec), coordinated by Foreign Relations Ministry, the Ministry of Science Technology and Innovation (MCTI) and the Inter-ministerial Commission for Sea Resources (Cirm). There were researchers from Univali, PUC-RS, CPRM, USP, Nihon University and a representative of Petrobras.

The expedition sailed from Cape Town, South Africa in April 13th with 6 researchers from Brazil and Japan aboard the Japanese research ship Yokosuka carrying the Shinkai 6500 submersible, which was the first submersible to dive off the Brazilian coast and is capable of diving to 6,500 meters. Due to bad weather in the beginning of the expedition the first dives were made at the São Paulo Dorsal, which is closer to the Brazilian coast and where various samples were taken and deepwater observation made during a number of dives that began around 4,000 meters and work up the water column. When the sea was too rough for diving the Shinkai 6500, the researchers used what they called the Deep Tow Camera, which films the seafloor while being towed by the ship. On April 30th, the Shinkai 6500 made its first dive at the Rio Grande Rise in a location named “Coral Garden”, in a canyon around 1,250 meters deep.

Going up the canyon nearly vertical walls the researchers noticed that these walls were covered with cold-water corals teeming with life, which is sustained by strong currents, also seeing various kinds of fish, lobsters, crabs, sponges, barnacles and large eels. The last dive at the Rio Grande Rise was made in May 4th at a location know as “Granite”, where researchers hoped to confirm the presence of stones normally found only on land. During this dive they say a great amount of underwater life and also collected the expected stone samples. 2 years ago a dredging expedition by the Brazilian Geological Institute (CPRM) had brought up pieces of granite, which is only found on land, therefore at the time it was thought that it was probably some mistake or accident.

The new expedition confirmed that it was no mistake and that the Rio Grande Ride is most probably a sunken continental mass that some are dubbing as Brazil’s Atlantis. Although the age of the granite samples was not disclosed, researchers agreed that it was certainly older than other rock samples found on the seafloor. The samples also indicated that there were possible deposits containing iron, nickel, manganese, cobalt, niobium and tantalum. There is also the possibility of methane gas deposits and possible even oil, yet future deepwater drilling expeditions will have to look into that. This expedition also serves another purpose for the Brazilian Government, as it intends to claim this area as part of its exclusive economic zone.

Sources: CPRM and G1