Scientists have made a ground-breaking discovery more than 4,000m (13,100 ft) below the ocean’s surface in the remote Clarion-Clipperton Zone in the North Pacific Ocean. In 2013, ocean scientist Andrew Sweetman noticed oxygen levels rising on the seabed. At first, he thought his sensors were faulty, but repeated tests over a decade confirmed the readings. Since then, researchers have discovered that polymetallic nodules on the seafloor, which take millions of years to form, might act like natural batteries. These “geobatteries” produce oxygen without sunlight through a process similar to seawater electrolysis, challenging everything we know about oxygen production in the ocean! The discovery could offer new insights into how life began on Earth. The Clarion-Clipperton Zone is rich in metals like cobalt, nickel and manganese that are in high demand for smart phones and renewable technology. Deep-sea mining for these minerals would remove the oxygen-producing nodules, changing how carbon is stored in the ocean and affecting local marine life. Head over to CNN to learn more.