American scientists found evidence of hydrothermal vents on the seafloor between New Zealand and Antarctica. More than 220 vents have been discovered worldwide – many on the Kermedec Arc between New Zealand and Tonga. So far no one has found them in the waters off Antarctica. The scientists were tracking plumes in the Southern Ocean of rare helium-3, an isotope found in Earth’s mantle and in the magma bubbling below vents, when they found a vent in the Pacific Antarctic Ridge. The likely sites cover 530km of the 6900km ridge, a chain of volcanic mountains on the seabed far from commercial shipping lanes.