Antarctica, CTD reterminations, and more Float deployments by Chanelle

I heard an astronaut speak once about their experiences in space, and I most vividly remember them telling a story about how they were outside doing some tedious work of greasing bolts. As he was greasing another bolt, he looked down and was awed by the beauty of the planet before him and the vastness of space. He said that in that moment he was struck by the juxtaposition of the mundane and the sublime. I’m assuming that he was referring to the bolt greasing as the mundane and the sublime as the Earth’s beauty and not vice versa.

 I couldn’t help but think of his words the other day. I was greasing the cap of Radiocarbon samples as people around me were talking excitedly about our proximity to Antarctica. Finally, I was able to leave my task to run to the bow of the ship. The night was crisp, but clear, and I was so excited I don’t even remember the cold. Reverently, I walked up the steps from the O1 deck, my views ahead blocked until I made it up the steps to the bow. From this vantage point I could see that just ahead of the ship was a wall of ice. We were right next to Antarctica. The moon was full and shone below on the ice, illuminating it in a bright glow. In the span of a few minutes I went from preparing Radiocarbon samples to gawking at views of Antarctica, and I thought I understood what that astronaut meant when he spoke of the juxtaposition of the mundane and sublime.

 

Sunrise over Antarctica.

Everything since that initial view of Antarctica has been a blur of activity.  As we were steaming over the continental shelf and away from the continent, the stations were close together and shallow.  As soon as sampling was done from one station, we would be putting the CTD back in the water again. We did a record number of stations that day.

The stations are spaced about 30 nautical miles from each other again which means we get a little bit of breathing room from one station to the next.  We made it to station 50 yesterday where we had a SOCCOM float deployment. The station got delayed some, though, because it was determined that the upper several hundred meters of cable were degrading. Normally, if you twist the cable the fibers should keep together and hold firm. Tony, one of the marine techs on board, twisted the cable, and you could see the fibers coming apart. This is scary because if the CTD is in the water on a cast and it experiences too much twisting or yanking, the cable could potentially snap, and we would lose the rosette. 

It was clear that the cable in poor condition had to be cut off, but a decision had to be made on when to do it. We were at station 50, and we are doing a two-day steam after 53. Ideally, we would have been able to wait until after 53, and do the laborious process of cutting the cable and reterminating the CTD during the steam. However, it was decided that the risk of losing the CTD was not worth the loss of a couple of hours, so we got to work right away.

For cutting the cable, a group of 6 of us or so got in formation in the Baltic room, and the winch operator let out the cable as the rest of us pulled on it and coiled it into an overlapping figuring 8. We would do this for about 250 meters or so, and then the cable would be cut. We made several of these figure 8’s until all the bad cable was removed. That’s when the real fun began.

We have on the ship John Calderwood who is one of the industry’s pros at CTD reterminations. He told me that he has done this specific kind of termination over 50 times. I watched him work, and I tried to be useful by handing him tools when he asked for them and holding things. A couple of hours pass, and the CTD has been successfully reterminated. The total delay is about 4 hours, which is pretty impressive considering all the work that had to be done to get the CTD back in the water safely. A large group of people worked really hard to get the CTD back in shape for another cast especially the winch operators, the marine techs, my fellow watchstanders and other students, and John.

Once the CTD was ready, we did station 50 without a hitch. The SOCCOM float deployed had been dubbed the “Tidal Wave”. I had done the design on this float and decided to put a pair of sunglasses on the wave based on the design of a t-shirt I like to wear. I went through the usual routine of a SOCCOM float deployment. Once the CTD was a couple hundred meters from the surface, the bridge was called to remind them a float was being deployed. That way they know to steam away slowly from station at only 1 or 2 knots. Then I get fresh deionized water, the sensor cleaning kit, and the deployment line, and I head to the wet labs, which is where the floats are stowed away. I remove the float from its wooden crate, and secure it to the side with some bungee cords. Then I clean the ISUS (nitrate) and FLBB (chlorophyll) sensors, and the float is ready to go!

I wait for the marine tech, Jenny, to finish recovering the CTD into the Baltic room. We then wait a little while for the ship to steam away from the station because we want to avoid putting the float right in the water where the ship has been sitting and risk polluting the conductivity cell of the float’s CTD. We then carry the float close to the stern on the aft starboard side. Jenny loops the deployment line through the hole in the stability disk on the float and then gently lowers the float into the water. 

Jenny is getting ready to deploy the “Tidal Wave”.

Once in the water, the float drifts away. At first, it is horizontal because the bottom cowling is filled with air, but once the cowling starts to fill with water, it turns upright. The float flips upright just as an albatross flies overhead. The Tidal Wave has been successfully deployed.