A Norwegian study has found a “substantial” amount of metals and minerals ranging from copper to rare earths on the seabed of its extended continental shelf, authorities said on Friday in their first official estimates. It could help cut dependence on China The resources estimate, covering remote areas in the Norwegian Sea and Greenland Sea, showed there were 38 million tonnes of copper, almost twice the volume mined globally each year, and 45 million tonnes of zinc accumulated in polymetallic sulphides. The NPD said its estimates showed resources “in place,” and further studies were needed to establish how much of those could be recovered with acceptable environmental impact