Getting Things Done

Saturday, October 1, 2005

Mary Goff and Carol Dundorf

Daily Report

The skies this morning were partly cloudy with WSW winds at 10-15 kts. A rain squall moved in around 4 this afternoon. Although swells are still large, they are not large enough to hinder dive operations that have continued since yesterday afternoon’s ABE rescue. Engineers examined ABE this morning after his entanglement with an errant piece of polypropylene line and the AUV appears to be in sound condition. “Polypro” is a real danger to sea life and submersibles. There was genuine concern that it posed a real risk to the manned submersible Alvin when it dives on the Endeavor Segment again. Our Jason crew uses wire instead of polypro for mooring lines in homing devices since they sink and eventually decompose.

After ABE’s rescue, Jason went back to work to remove an older microbial incubator and insert a newer, more sophisticated one in a chimney at Hulk. Dr. Geoff Wheat supervised the squeeze sampler that was used at two nearby locations. By 6:00 am Jason’s crew had taken a gas-tight fluid sample at Hulk and deployed an osmosampler that will measure the chemical changes in hydrothermal vent fluid over the next year. It is designed to collect samples of over 35 different compounds.

After a brief delay due to a problem with the ship’s DP (dynamic positioning) system, Jason II flew to a diffuse vent site and took two major fluid samples. On its way to the waiting elevator Jason’s right arm was able to harvest a macrofauna sample with tubeworms, limpets, and microorganisms. These were loaded into the biobox and sent up with the elevator around noon. According to Spence Nyholm, live organisms will be placed in a special pressurized bottle for study while nonliving specimens will be preserved for genetic analysis.

Later in the day a short period seismometer was inserted at the structure named Grotto. While waiting for an elevator the Jason crew was able to test a strobe camera. Some of the test pictures reveal heavily sedimented sheet flows, probably the result of a collapsed lava lake, according to Deb Kelley.

As this is being written Jason is heading for the structure named Roane to continue working throughout the night. It has been a productive day.

Impressions

The Bow Thruster
Carol Dundorf, REVELer

This ship is amazing. It has the ability hold an exact position and maneuver in almost any direction. It can even go sideways or turn in one place (on a 274 foot dime). It can do this because of a system of thrusters that can each rotate 360°. There are two in the stern and one in the bow. For those of us with rooms below deck near the bow, the Bow Thruster plays havoc with our ability to sleep. It is especially bad when Jason is in the water and it’s critical for the ship to maintain an exact position. It’s nice when the ship is moving slowly forward in the water and the bow thruster is not in use. It seems that everything inspires poetry on this cruise. Including the bow thruster.


Lying in my bunk I listen to the high-pitched hum.
A click, a turn, and then a rumble.
It vibrates the bed and my body with vigor of the mighty engine beneath.
The work is never done in the quest to maintain a dynamic position.
On and off again. Silence for a brief moment.
A click, a turn, and then a rumble.
Sleep comes slowly during this effort.
Waves gently rocking the bow is my hope for sleep.

Daily Question

  • How is everything? Why do black smokers make black smoke?
    Cristo Larios,     O’Leary Junior High School, Twin Falls, ID


    Mrs. Dodds says everything is really exciting, Chris. Every day is bringing new surprises!

    In answer to your question, that “smoke” isn’t really smoke at all, but hydrothermal fluid rising from a vent in the seafloor. The hot fluid itself is composed of many different elements and compounds. According to Dr. Jeff Wheat, a geochemist, fluid samplers are presently looking at more than 35 different hydrothermal chemicals that may effect the growth of vent microbes.

    While the hot fluid is still inside the seafloor it is colorless and transparent. It contains a lot of sulfide (S 2) ions along with metals like iron, copper, and zinc. In the hot fluid under the seafloor these chemicals remain dissolved, but when the water hits cold seawater they become solid again (precipitate) in the form of powdery minerals that look like smoke. The mixing with seawater also causes chemical reactions to occur, creating new minerals like iron sulfide (FeS2, pyrite or “fool’s gold,”) copper iron sulfide (CuFeS2, chalcopyrite,) and zinc sulfide (ZnS or sphalerite.) According to Deb Glickson, graduate student, tiny grains of these sulfide compounds are what give the fluid its blackish appearance. And for your information, not all smokers emit black “smoke.” Depending on the location of the vent region and the composition of the rocks beneath it, there can also be white smokers. These have a whitish appearance when the gypsum and zinc minerals precipitate out of solution. (See the Science section of the REVEL website and click on “Smoker Development” for more information.)

  • How do tube worms breathe down there in that environment? Do they respire aerobically?
    Brittany Janz ,     Anacortes High School, Anacortes, WA (Mrs. Swanson’s class)


    Hello, Brittany, Sounds like you’ve been studying how cells work. As you know every cell in an organism needs energy for metabolism. They need several things to do this. Two of them are an energy-rich compound and an electron acceptor, like oxygen, that helps release the energy in the compound. Human cells get much of their energy from energy-rich glucose when it is broken down with the help of oxygen. Oxygen is one of several substances that help release energy by accepting electrons. As I think you know, when oxygen is used as an electron acceptor we call this process aerobic respiration. How does this apply to those weird and wonderful tube worms near hydrothermal vents? First of all these amazing organisms can’t eat for themselves since they don’t have a mouth or a digestive track. They depend instead on the food from tiny bacteria living within them in a special tissue called a trophosome. The bacteria manufacture food from the sulfide compounds in the hydrothermal fluid and share some of it with their host. The tube worm does its part by delivering oxygen to the bacteria by means of a well-developed circulatory system that includes the bright red plume that collects oxygen from the water. Because the oxygen-carrying compound, hemoglobin, is the same one we humans use, the color of tubeworm blood is bright red like ours. And since they (and their symbiotic bacteria) are using oxygen as an electron acceptor, we would consider this aerobic respiration.