Fifteen-foot-long hypodermic needles strong enough to penetrate the volcanic rocks that make up the Earth's crust were among the novel devices used to collect samples from sites on the Juan de Fuca plate 200 miles off the coast of Washington and Oregon.
Scientists have known for 20 years of microorganisms that thrive in the acidic iron-, sulfur- and heavy-metal-rich fluid environments in areas where seafloor is being created at mid-ocean ridge spreading centers. These areas are subject to frequent volcanic eruptions and can have fields of hydrothermal vents that pour superheated water as hot as 750 F into the oceans.
As visually spectacular as such areas can be, they represent only a tiny area of the seafloor. Far more of the seafloor is tens of millions of years old.
"The types of seafloor environments we sampled last summer are found everywhere in the ocean. This argues, although it doesn't prove, that oceanic crust may be a microbial incubator of global proportions," he says.
Scientists still haven't sampled widely enough to say for sure, and it was just Jan. 3 when the first report of microbes living in 3.5 million-year-old crust was published in the journal Science by Johnson and co-authors from University of Hawaii, Oregon State University and University of Illinois.
Now Johnson and another group of scientists report in Eos that they retrieved and are actively growing microbes from both old and young seamounts "old" being 3.5 milli
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Contact: Sandra Hines
shines@u.washington.edu
206-543-2580
University of Washington
18-Mar-2003