Before revision: ISA estimates that the total amount of nodules in the Clarion Clipperton Zone exceeds 21 billion tons (Bt), containing about 5.95 Bt of manganese, 0.27 Bt of nickel, 0.23 Bt of copper and 0.05 Bt of cobalt.
After revision: The International Seabed Authority (ISA) estimates that the total amount of nodules in the Clarion Clipperton Zone exceeds 21 billion tons (Bt), containing about 5.95 Bt of manganese, 0.27 Bt of nickel, 0.23 Bt of copper and 0.05 Bt of cobalt.