September 26, 2008
In Barren Patch of Ocean, Hope for Life
An area of the Pacific Ocean once thought to be cold and barren is warmer than scientists thought, a new study finds. The seafloor there might be teeming with life.
A group of researchers dropped probes down to a flat region of the Pacific Ocean floor off the coast of Costa Rica and about the size of Connecticut to gauge the water temperature and flow there.
"It's like finding Old Faithful in Illinois," said study team member Carol Stein of the University of Illinois at Chicago. "When we went out to try to get a feel for how much heat was coming from the ocean floor and how much sea water might be moving through it, we found that there was much more heat than we expected."
The sea floor in this region, which lies some 2 miles below the ocean surface, is marked by 10 widely separated outcrops or mounts that rise from sediment covering the ocean crust made of volcanic rock about 20 to 25 million years old.
Large amounts of water gush through cracks and crevices in the ocean crust like geysers and pick up heat as they move through the insulated volcanic rock. While not as hot as water that runs through mid-ocean ridges formed by rising lava, the water is still much warmer than expected.
This warmth opens up the possibility that the area could support life, such as bacteria, clams and tubeworm species recently found to be living near hot water discharges along mid-ocean ridges.
"It's relatively warm and may have some of the nutrients needed to support some of the life forms we see on the sea floor," Stein said.
The researchers hope to follow up this study, detailed in the September 2008 issue of Nature Geoscience, by examining other areas of the ocean floor to see if they can find any similar to the one off the coast of Costa Rica.