January 15, 2000
From: Carolyn J. Sheild
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
7th grade Science Teacher
Clarke Middle School
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
Thanks for your help,
Marine Science Teacher
Nantucket High School
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
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
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
Rene P. Cap
Paul Revere School
Room 104 Grade 6
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
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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