 Sars" (named after the Norwegian marine biologist Georg Ossian Sars and launched in May 2003).The vents were located using a remotely controlled undersea vehicle.The five active chimneys of Loki's Castle are venting water as hot as 300 °C (570 °F) and sit on a vast mound of sulfide minerals which is about 825 ft (250 m) in diameter at its base, and some 300 feet (90 m) across its top.