This is a closeup of the bottom of a vent called "Bio 9" the large red-tips are the tops of the Riftia that I have already talked about. The smaller red-tips are the tops of a different, smaller tubeworm called Tevnia jerichonana.

Temperature probe used by Tim Shank and Dan Fornari.



One of the questions surrounding research at hydrothermal vents is the lifetime of a vent and how each vent changes over time. On this cruise, Tim Shank and Dan Fornari are using changes in the temperature of a vent to examine the evolution of specific vents over time. Alvin is equiped with two temperature probes, one for low temperatures (less than 40-degrees-C) and one for temperatures greater than 40-degrees-C. On a dive, the pilot of the submersible will use the temperature probe to get temperature measurements as the water comes out of the vent. The vents here are up to 375-degrees-Celsius. On the surface water boils at 100-degrees-Celsius, so why is the water down here not boiling? Because of the depth, the pressure is so great that the water will not boil until it reaches over 400-degrees-Celsius. Here at 9 North, the vent water does not get that hot, but on the East Pacific Rise in the southern Pacific Ocean there are at least two vents that are hot enough to boil.

This is a wand that is attached to the "Sipper." The sipper is designed to collect discrete, 10 mL water samples for analysis back at the surface. In this picture the shimmering water that is coming from the vent is not as hot as some of the "black smokers" that are usually the "poster children" of hydrothermal vents.

Closeup of the white filaments on the temperature probe.

Tim and Dan also deploy long-term instruments that will measure the temperature of the vent for the next year, long after we have returned home from this cruise. These temperature probes are inserted into a vent to be recovered on future cruises. As the probes are recovered, new probes are put in their place to continue this valuable data set. The tip of the temperature probe is bent so that it can hang from the top of the vent. On this cruise, we returned to one site to find that 5 meters of chimney had grown up past one temperature probe. It took quite a bit of digging to get that probe out without knocking over the whole chimney. At times the probes will come up with pieces of the chimney around the tip of the probe (picture). The geologists like this since they can link the temperature data to the type of rocks being formed.

As a microbiologist, I am interested in the temperature measurements of the vents so I can get an idea of what temperatures the microbes might be exposed to on a daily basis. Apparently no microbes grow in the chimneys with temperatures greater than 200-degrees-Celsius, but the temperature measurements from more diffuse areas of flow are helpful to me. A side bonus to the temperature probe deployments is that they often come back to the surface covered in microbes that I can work on in the lab.