Deep-sea miners are ready to get down to work

By Hal Hodson

Mining in the deep is an arresting prospect. It involves robotic vacuums the size of combine harvesters lowered thousands of metres onto the abyssal plains of the Pacific ocean. They rumble along the seabed, sucking up nodules of manganese, copper, cobalt and nickel—metals whose supply is crucial to efforts to electrify the global economy. These nodules sit unattached on the seabed thanks to millions of years of accretion of metal particles in one of the stillest places on the planet. A patch of the Pacific ocean seabed called the Clarion Clipperton Zone (CCZ) holds nodules containing quantities of these metals that are roughly equivalent to all terrestrial reserves.