Discovered just 2 years ago during a National Science Foundation-funded expedition in the mid-Atlantic Ocean, Lost City has the tallest vents ever seen the 18-story behemoth at the site dwarfs most vents elsewhere by at least 100 feet. Water is circulated through the vent field by heat from serpentinization, a chemical reaction between seawater and the mantle rock on which Lost City sits, rather than by heat from volcanic activity or magma, responsible for driving hydrothermal venting at sites scientists have been studying since the early 1970s.

If hydrothermal venting can occur without volcanism, it greatly increases the places on the seafloor of early Earth where microbial life could have started. It also means explorers may have more places than previously thought to look for microbial life in the universe.

Although the Lost City vent field is a youthful 30,000 years old, Lost City-type systems might be able to persist hundreds of thousands, possibly millions, of years, says lead author Gretchen Frh-Green of the Swiss Federal Institute of Technology and co-authors from the University of Washington, Duke University and National Atmospheric and Oceanic Administration. One can imagine how such stable, long-lived systems pumping out heat, minerals and organic compounds for millennia might improve the chances for life to spark and to be sustained until it could take hold, say these scientists.

"It's difficult to know if life might have started as a result of one or both kinds of venting," says Deborah Kelley, University of Washington oceanographer, "but chances are good that these systems were involved in sustaining life on and within the seafloor very early in Earth's history."

As far as longevity an
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Contact: Sandra Hines
shines@u.washington.edu
206-543-2580
University of Washington
24-Jul-2003