Science Report:
Today we are finishing up the last of our CTD casts before heading home. The final casts will complete a circular pattern around Axial Volcano to better define the outer limits of the hydrothermal plume. While these casts are showing little indication of the plume, it is important to map the plume limits in order to get a better understanding of the total effect it may have on the environment.

Yesterday we deployed the five moorings that will continue to collect data after we depart for home. We deployed two basic types of moorings: MTR (miniature temperature recorder) moorings, and multi-instrumented moorings. The latter of the two is a complex mooring designed for the insertion of various instruments as we deploy the mooring. We start off by lowering a 1500pound anchor over the side, followed by an acoustic release. The anchor is lowered by spooling a premeasured rope over a capstan, a device that mariners use to pull in or let out lines such as mooring lines. At predetermined intervals, we tie off the end of the line with the anchor and "break" the line, that is disconnect the line at a spot where chain and shackles have previously been inserted. We then place our instruments in these spaces, such as the in situ pump that Dr. Baker talked about or current meters.

The current meters will allow us to follow the ocean currents for the entire year while the mooring is deployed. These data will tell us whether the current was carrying the vent emissions towards or away from our instruments when they were sampling.

You may wonder what happens at the end of the line? We attach a ship's line to a pull release that attaches to the last floats of the mooring, which would be the top of the mooring as it floats in the water column. With a quick pull of the line, as Carol can be seen doing, the whole array is sent quickly to the bottom at the location that we want.

The second type of mooring, the MTR, is much easier. We deploy this type of mooring anchor last. We start by deploying our top floats first and "stream" them out behind the ship. We use quarter inch kevlar line, which has predetermined spots to attach the MAPR's or MTR's. We attach these with tie wraps and tape, which are essential tools in the oceanographer's toolkit. At the end of these moorings we attach our release and a 500pound anchor. When we reach our predetermined spot, we lower the release into the water and literally kick the anchor over the side. Moorings are a nice way to break up some of the repetitive work of the CTD's and require close work between the ship's deck crew, the officers on the bridge, and the science party.

Tomorrow we turn towards home, and start the tedious task of packing everything away in an organized manner, cleaning all the labs, and preparing to unload all of our gear in Seattle.