Mystery oxygen source discovered on the sea floor — bewildering scientists

Something is pumping out large amounts of oxygen at the bottom of the Pacific Ocean, at depths where a lack of sunlight makes photosynthesis impossible. The find has surprised scientists and the source remains a mystery. The oxygen might be generated by metal-rich mineral deposits, or nodules. To researchers’ surprise, they measured voltages of up to 0.95 volts across the surface of the nodules. It is possible that the nodules catalyse the splitting of water into oxygen and hydrogen, but more experiments are needed.