FeMO4 Dive Cruise 2009
Report Day 10 -- Saturday 10 October 2009 -- A Major What?


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Olivier and Sarah conducting water
sample analyses

Olivier disassembling a Major

Jason has been up and down and up and down and now the Kilo Moana is on the move again. With so many samples on board I decide to go down to the labs to see what the scientists are working on. Olivier and Sarah will conduct isotope analyses on the hydrothermal vent water samples that have been collected. Most of the onboard chemistry is conducted by Olivier, Sarah, and Deb.

I am curious how water is collected from the hydrothermal vents so I ask Olivier to explain it to me. He pulls out a device that he calls a Major. I ask, “A major what? “ In his charming French accent he says, “Just a Major. “ Of course I’m not satisfied with this answer, so I press on. “But a major what? – Does it stand for something?” Beth steps in to clarify, “It’s a Major water sampler.” Oh…well that makes sense…


Sarah holding the Major
snorkel

I ask Olivier to explain how it works. Here is what he tells me. The Major’s primary components are a cylinder, a plunger, and a snokel. The plunger is depressed and a pin holds it in place. The Major is placed in Jason’s basket and he descends to the ocean floor. When the scientists locate a hydrothermal vent, Jason picks up the Major and inserts the snorkel into the vent.


The Snorkel of a Major sucking the
hot water out of a hydrothermal vent

Next, Jason raises the pin which releases the plunger. The plunger moves outward drawing the hot water into the cylinder. When the cylinder is full, the plunger stops moving. Then Jason puts the Major back in the basket. When Jason returns to the surface, Olivier retrieves the Major, brings it to the lab, and suctions out water samples for analyses. Sometimes Olivier inserts a filter between the syringe and the collection bottle to filter out all particulate matter.

Deb tells me that it is a 0.2 micron filtration. It doesn’t mean much until he explains how small 0.2 microns is in comparison to the size of a bacteria. The bacteria that grow on Lo’ihi are 2 microns long and a half micron wide. So the water passes through the filter but the bacteria get stuck in the filter. Deb tells me that the bacteria are one hundred thousand times larger than a water molecule! That’s a big bacteria!!


Deb and Olivier suctioning water
samples from the Major

After all the water sample is suctioned out, Olivier begins to disassemble the Major. I am shocked at how many parts it has. There are 16 pieces and 23 screws in each Major. It’s made of high purity titanium and costs $15,000 each. Olivier has brought four Majors on the boat with him from Woods Hole Oceanographic Institute.


Suctioning water samples from the
Major

Finally, I ask, “What do you use all these water samples for?” He tells me that he is studying the composition and concentration of the major and minor elements on the Lo’ihi seamount. He tests the water samples for major elements such as magnesium, sodium, chloride, calcium, and sulfate and minor elements such as iron, manganese, cobalt, nickel, potassium, and phosphorus. His goal is to understand the hydrothermal circulation and chemical exchange between the water and the rocks.

In addition, Olivier tests the pH and alkalinity, Deb tests the phosphate concentration, Sarah extracts the organic compounds, and Beth studies the nitrate reducing bacteria. All this from one water sample!!!


A Major puzzle

By now, my head is spinning with data, facts, and new information. It’s been a very educational day and it's only twelve o’clock noon!! Time for Lunch!



Lisa Kohne onboard the R/V Kilo Moana
10 October, 2009


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