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From: Carolyn J. Sheild
Hi Susan,
How are things at sea? I was reading the hypothesis section about the pyrite formation and microbes getting energy spontaneously or from the hydrogen released during the reaction. (1 vs.2) Is there a way scientists will be able to know which is occurring? If so, how? I’m planning on having my students look at the website this Fri. Jan. 14. So I thought I’d need a little more background in case my students ask more particulars about the science. (In addition to your questions, I’m planning on having my students answer some of my own questions regarding the cruise objectives, etc.) So let me know what you think about my question...Look forward to hearingfrom you!
Take care,
Carolyn Sheild
7th grade Science Teacher
Clarke Middle School
Lexington, MA

Hi Carolyn:
Thanks for the message - good to hear from you! Sorry it has taken a bit longer to answer but there have been some communication problems both at WHOI and here, but now they are fixed.

I have checked with George Luther, the geochemist on this cruise who is working on this project. It may be that the equation that is written on the web site is a little confusing in that it includes hydrogen AND energy. The important point is that the reaction of hydrogen sulfide and iron monosulfide is an energetically favorable reaction in that it produces hydrogen. The hydrogen is the key - as it can then be used directly by an organism as an energy source, or in fact, if carbon dioxide is present, it can react inorganically to form organic matter.

The hypothesis that is being tested is that hydrogen is the key for the microbes. The way this will be tested is that microbes will be “fed” hydrogen sulfide and iron monosulfide to see if they live. If they do, then it means they are using the hydrogen that is produced as their energy source. The test of this would then be to “feed” them hydrogen - if they grow, this would prove it.

From: Valerie Hall
I was wondering which submersibles (Alvin, Jason, ABE, Remus, others?) will you be using in the explorations of vents in the Gulf of California. I also wonder if you know yet what the rate of seafloor spreading is in that region. Finally, is it true that the Gulf of California is considered an ’embryonic ocean“?

Thanks for your help,
Valerie Hall
Marine Science Teacher
Nantucket High School

Hi Valerie:
We are using Alvin out here at the hydrothermal vents in the Guaymas Basin. The spreading rate is 6 cm/year, similar to the East Pacific Rise. It is an embryonic ocean in the sense that about 5 million years ago, Baja California was attached to the mainland, and sea floor spreading has opened up the Gulf of California.

From: Rene P. Cap
How close can you bring the sub to a black smoker to retrieve samples?

The arm of Alvin has a reach of about 6 feet, but you really need to get about 3 feet away to sample. That is usually OK as the hydrothermal fluid cools very quickly when it enters the ocean. However, sometimes we get too close! See the Daily Journal for 14 January for a description of some burned equipment!

Is the smoker active full time or does it function similar to a geyser?

That is a very good question! It doesn’t discharge intermittently every few minutes or so, like a geyser. When you look at a hydrothermal vent, it is discharging all the time you are looking at it. However, we do know that vents “shut down” on the East Pacific Rise after tens to a hundred years, either because the heat source driving them cools or because the fluid flow pathways clog up with minerals. They may reactivate later - but the mechanism is different from a geyser, which has to build up pressure.

Is this an environment where one could study extremophiles?

Absolutely - in fact, one of the projects out here is funded by a National Science Foundation program called Lexen - Life in Extreme Environments. The conditions at a vent are one of the most extreme environments on Earth as they are at high temperatures and pressures, as well as having unusual chemistry.

Thanks,
Rene P. Cap
Teacher
Paul Revere School
Room 104 Grade 6

From: Apollo6187@aol.com
what is it like going under water and researching the hydrothermic vents. It must be cool seeing all the fish huh. I am from miss Shields class she was one of the teachers chosen for this activity or what ever it is. but I think you are doing a good job so keep up the good work.

Thank you for your question. It is really exciting going underwater in the submersible Alvin. For the first several hundred meters, the light slowly fades and then it is completely dark. In the submersible, there is only one small light as it is important to save the battery power until we get to the bottom. It also gets cold inside as the water gets cold outside so the people have to take lots of clothes with them. Once we get to the bottom and turn the lights on, everyone is very busy making observations and taking samples. We don’t see that many fish except around the vents where there is lots of food for them.

From: Haggerty
What do you do to remind you of home?

Thanks for your question. I asked several people, and they do all sorts of different things! Of course, we now have e-mail which makes it much easier to communicate with home, although the messages have to be short because they have to be sent by satellite, and using a satellite is very expensive. Many people bring pictures of their families and homes, or letters from friends. Some even bring their favorite foods and recipes, or even a pillow that they have at home they particularly like.

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