ICY SCIENCE: SCIENCE SPACE ASTRONOMY Spring 2014 | Page 35

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A vent tower at Lost City, with the robots Hercules and Argus
looking on. Credit: Deborah Kelley University of Washington, IFE
URI-IAO, Lost City Science Party, NOAA

In 2000, a new kind of vent community was found on the sea
floor of the Atlantic Ocean. It’s called the Lost City vent field and it
isn’t based on volcanism, but on rock-water reactions that release
energy as heat, raising the water temperature to just around
90-100 degrees C. This system has been in the same area for possibly over 20,000 years, building vent towers of calcium carbonate
rock - the same mineral that builds coral reefs and makes up the
shells of many sea animals. One of the towers, named Poseidon,
is taller than an 18-story building. These vents pour out water
rich in hydrogen and methane and carbon dioxide. These chemicals are part of a classic energy chain used by some archaea.
Microbes that live in the vents “eat” the methane, making more
complex carbon molecules that then feed other microbes. It is
both a non-living and living cycle, interwoven and based on the
chemistry of the rocks and water, with no sunlight needed.

The carbonate towers build structures that are filled with life. The walls
inside and out are covered in microbes, and some tiny, translucent-shelled
animals like crabs live in the crevices. Credit: IFE URI-IAO, Lost City Science
Party, NOAA

ICY SCIENCE | QTR 2 SPRING 2014