WSU Astrobiology Seminar Series 2006/7 Academic Year

Deborah Kelley contrasts the white porous texture of a sample from the Lost City's carbonate chimneys with a sample from sulfide chimneys studied since the 1970s. Photo credit: University of Washington.
Friday, November 17, 2:10-3:00 p.m, CUE 203
Deborah Kelley

Hot Vents, Black Smokers, and the `Lost City:' Deep Sea Ocean Exploration


In 1977, the world was astounded by the discovery of underwater hot spring systems hosting rich oases of biological communities supported by gases released from active volcanoes. The associated metal deposits and diverse biota of clams, tubeworms, and swarming shrimp, which have adapted to these extreme environments have become synonymous with submarine hydrothermal vents. In 2000, however, we serendipitously discovered a new kind of seafloor hot spring system as astounding as any black smoker field found to date.

This new ecosystem, called the Lost City Hydrothermal Field is of stunning, ghostly beauty. Located at near the Mid-Atlantic Ridge, the field hosts numerous limestone monoliths that tower > 200 feet above the surrounding seafloor. Stalagmite-like parasitic growths three stories tall, gently vent fluids at temperatures up to . Bathed in solutions with properties similar to Drano, the chimneys are teaming with microbial life that thrives in the absence of sunlight. Surprisingly, these single celled organisms obtain life-sustaining energy from hydrogen and methane gases, and hydrocarbons formed through rock alteration processes that occur at depth within the mountain.

This discovery highlights that there are extensive, unexplored regions of the ocean basins that may host novel life forms, which do not require volcanoes for their support. It is also important, however, because Lost City may be our closest analogue to hot spring systems active during early Earth. If this is true, examination of geo-biological processes operative within this field may provide new insights into how life evolved on this planet. Recent discoveries on Mars hint that similar environments could also have been present during its evolution. With these thoughts in mind, it is likely that within the next decade profound, unimaginable discoveries will be made not only about our oceans, but about the oceans of our solar system as well.

This talk will include new imagery of these hot springs and the novel animal communities that thrive at depths of 7,000 feet beneath the oceans surface.