DEPTН CHARGE

Companies are gearing up to MINE the SEAFLOOR, targeting rocks rich with metals that are essential to our EV-powered future. THE BIG QUESTION: How much OCEAN are we willing to SACRIFICE?

- VINCE BEISER

In October of last year, an enormous new creature appeared on the seabed of the Pacific Ocean, about 1,400 miles southwest of San Diego. It was a remote-controlled, 90-ton machine the size of a small house, lowered from an industrial ship on a cable nearly 3 miles long. Once it was settled on the ocean floor, the black, white, and Tonka-truck-yellow contraption began grinding its way forward, its lights lancing through the darkness, steel treads biting into the silt. A battery of water jets mounted on its front end blasted away at the seafloor, stirring up billowing clouds of muck and dislodging hundreds of fist-sized black rocks that lay half-buried in the sediment.

The jets propelled the lumpy stones into an intake at the front of the vehicle, where they rattled into a steel pipe rising all the way back up to the ship. Air compressors pushed the rocks up in a column of seawater and sediment and into a shipboard centrifuge that spun away most of the water. Conveyor belts then carried the rocks to a metal ramp that dropped them with a clatter into the ship's hold. From a windowless control room nearby, a team of engineers in blue and orange coveralls monitored the operation, their faces lit by the polychromatic glow from a hodgepodge of screens.