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Join DIVE AND DISCOVER on a one-week expedition to some of the Earth's most spectacular hydrothermal vents.

DIVE AND DISCOVER's first voyage takes you to the Gulf of California, the sliver of ocean separating Baja California from mainland Mexico. It's a place of stunning scenery where mountains rise sharply above blue water and white beaches, where the warm waters are rich in marine life, and where California gray whales return every winter to give birth.

mid-ocean ridge

transform faults

In 1980, researchers from the Scripps Institution of Oceanography in La Jolla, California, sent the deep-sea robot DeepTow down to map one of these mid-ocean ridge spreading centers-the 2,000 meter-deep Guaymas Basin. There they discovered spectacular black smoker vents. Surrounding the smokers was a lush community of deep-sea organisms ranging from tubeworms and giant clams to the tiny microorganisms that feed off of chemicals spouting out of the vents.

Now a team of scientists led by Dr. Craig Cary and Dr. George Luther of the University of Delaware and Dr. Anna-Louise Reysenbach of Portland State University has returned to Guaymas Basin. The scientists will dive to hydrothermal vents on the seafloor on board Alvin, the Woods Hole Oceanographic Institution’s deep-diving research submarine. There they will map the vents and surrounding seafloor, collect minerals from the chimneys, and analyze the chemicals spouting up from the vents. Finally they will collect and study the fascinating organisms that depend on these chemicals to survive.

This research will not only provide valuable information about deep-sea vent biology and chemistry, it may provide tantalizing clues about the origin of life on Earth.

Join Drs. Cary, Luther and Reysenbach and their team of scientists, students and engineers on each exciting dive into the Guaymas Basin.

Objectives
The biological communities that have evolved around hydrothermal vents thrive in conditions that are almost unimaginable. The organisms live in total darkness. They feed off of chemicals that are toxic to most other living things, including people. Some of these organisms survive in water hotter than 100°C (212°F).

Yet scientists now hypothesize that the first life on Earth may have evolved under these hot and corrosive conditions. Genetic analysis has shown that many of the microbes that live around vents today are closely related to these first microbes.

Scientists diving to to vents in Guaymas Basin will begin to test the theory that life may have originated around hydrothermal vents or under similar conditions. They will search for clues in the chemicals coming out of the vents and among the microbes that live around the vents.

Pyrite the Key?
The Guaymas Basin team is focusing their attention on one mineral in particular. This mineral is called pyrite, or fools gold. Black smoker chimneys are made of pyrite.

Pyrite is formed when hydrogen sulfide (H2S) and iron monosulfide (FeS) react. Both of these chemicals are present in the hydrothermal fluid that jets out of the vents.

Here is the chemical reaction:
hydrogen sulfide (H2S) + iron monosulfide (FeS) -- -----> pyrite (FeS2) + hydrogen gas (H2) + energy

Some scientists now propose that this chemical reaction may have played a key role in the origin of life.

Providing Energy for Life
All organisms need energy to survive. We get energy from the food we eat. Plants get energy from the sun. The microbes that inhabit hydrothermal vents get their energy from chemicals in the hydrothermal fluids. The process by which organisms harvest energy from chemicals is called chemosynthesis.

Some scientists propose that the first microbes may have gotten their energy from the chemical reaction between H2S and FeS that forms pyrite. Another possibility is that the microbes got their energy from hydrogen gas that is produced during the pyrite reaction. Today, there are many microbes living in high-temperature waters that use hydrogen as an energy source.

Testing the Hypothesis
The scientists on this cruise will begin to test the hypothesis that life originated around hydrothermal vents or under similar conditions. One of the first tests is to try and find microbes living today that use the pyrite reaction to get energy.

1. They will use an extremely sensitive chemical sensor called a voltametric microelectrode attached to Alvin to detect hydrogen sulfide (H2S) and iron monosulfide (FeS). Remember that these are the chemicals that react to form pyrite.
2. Using Alvin, they will collect vent chimney samples and microbes from areas where they find high concentrations of H2S and FeS and bring them back up to the ship for analysis. They will identify and catalog all of the microbes they find.
3. Finally they will try to culture (grow) the microbes in an environment where H2S and FeS are reacting to form pyrite. Using this experimental approach, the scientists will test whether these microbes can survive by using the energy from the pyrite reaction.

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