Mining the deep ocean

More than 13,000 feet below the surface of the Pacific Ocean, a more-than-70- ton machine trundled like a tank on its caterpillar tracks for a tenth of a mile — sucking up potato-sized nodules of rock packed with copper, manganese, cobalt and nickel. It was 2022, and that pilot run of a subsea harvester by a Canadian business, The Metals Company, was pronounced a success. The company is working to get a green light to deploy similar machines for commercial harvesting over an area of 65,000...