Big catch. Oceanographers lower 1.8 metric tons of mineral deposits onto deck.

Deep-Sea Smokers Raised

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Four "black smokers"--mineral chimneys formed by undersea hot springs--have been hauled ashore for an unprecedented scientific inspection by scientists at the University of Washington and New York's American Museum of Natural History. Wrested from the ocean bottom with the aid of a chainsaw-equipped robot submersible and a crane, the chimneys arrived in Seattle on Saturday--complete with the microbial communities and other life-forms they harbor

The smokers were found 2250 meters under the sea at hydrothermal vents along the Juan de Fuca ridge, a line of undersea volcanoes some 300 kilometers off Washington state and Vancouver Island. Sea water filters down through cracks in the crust and picks up minerals from rocks heated by the magma below. The hot water then percolates back up through the crust; when it hits the cold sea water, dissolved minerals precipitate out, creating chimneylike structures. Tiny particles of sulfide minerals make the vent appear to be belching black smoke.

Picking apart the smokers, scientists hope to learn more about heat transfer from Earth's core, seawater chemistry, ore formation, and ecosystems that do not depend directly on sunlight. One of the active chimneys, which was venting water at 350 degrees Celsius, hosted a rich collection of creatures known as extremophiles--animals such as sea spiders, snails, limpets, and worms that flourish in harsh environments. Of particular interest to scientists are the unusual hydrogen sulfide-metabolizing microbes living inside the rock, says expedition co-leader Edmond Mathez, chair of the museum's Department of Earth and Planetary Sciences. "We've never sampled the interior of [black smoker] rock to understand the conditions under which these creatures live or the maximum temperature at which life can exist," he says.

The expedition, filmed for the TV documentary program NOVA, was chronicled online. Several of the smokers--the largest is 1.5 meters tall and 60 cm across--will be featured at the New York museum's new Hall of Planet Earth to open next spring.

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