So far, the polymetallic nodule resources have been estimated in four stages. During the first stage completed in 2007, the overall resources were estimated for both of the exploration sectors B1 and B2, focusing on selected metals (Mn, Ni, Mo, Co, Cu and Zn). During the second stage (2011) resources within the H11 exploration block were estimated, both for the nodules and four major metals: Co, Cu, Mn and Ni. In the third stage (2015) a similar estimation was completed for the H22 exploration block. The fourth stage was completed in 2020, re-estimating resources in B2 sector (evaluating exploration blocks H11+H22, H33, H44 and exploitable block H22_NE). Ordinary geo-statistical kriging method was applied to estimate the distribution and amount of resources. Seabed areas free of nodules, the areas of ocean-floor slope over 7° and volcanoes were not included into the resources estimation.

Mineral resource estimate of wet polymetallic nodules in B1 and B2 sectors of the IOM Exploration Area. Cut-off 10 kg/m2 of wet nodules (2020):

Note: Sector B2 includes exploration blocks H11, H22, H33, H44 and exploitable block H22_NE