The bizarre hydrothermal vent field discovered a little more than two years ago surprised scientists not only with vents that are the tallest ever seen — the one that’s 18 stories dwarfs most vents at other sites by at least 100 feet — but also because the fluids forming these vents are heated by seawater reacting with million-year-old mantle rocks, not by young volcanism.
April 17, 2003