By Frankie Pavia
I was talking to a colleague on board today while we were subsampling sediment cores we had taken from the last station. The cores were especially interesting – the entire surface was covered in manganese nodules, some the size of baseballs. Our conversation was interrupted by a mysterious occurrence. In one of the subcores we’d taken, there were manganese nodules sitting at 15 cm and 18 cm deep in the sediment. Conventional wisdom and that infamous beacon of knowledge, scientific consensus, stated that the nodules stayed on top of the sediment and were never buried after formation. There were also bright streaks of white carbonate nearby polluting the otherwise pristine red clay that occupied the rest of the core.
We had been talking about what it would be like to be back on land after a long cruise like this. My colleague has been to sea a few times before, and I was curious as to what she thought would be the most different to us upon returning to dry land. She explained that for her, the biggest change was interacting with strangers. There are only 64 people aboard the boat, and by now I can match a name to every face. I may not speak to them regularly, but I may have seen how they take their coffee, or what kind of cake they prefer in the afternoon, or exchanged a casual “moin” (hello) in the hallway. I haven’t seen a new face in almost four weeks.
I anticipated that being at sea might be lonely. I knew I would miss my friends and family. It has hit especially hard the past two Sundays when my hometown NFL team, the Seahawks, have played playoff games. I usually watch Seahawks games with my best friends in New York and fire texts back and forth to my friends I grew up with the entire time. Those are the times I am most in contact with the people I love. Sitting alone in my cabin aboard the ship, frantically updating Twitter, trying to follow the happenings and score of the game, feels especially isolating.
In a way, being a scientist is an isolating endeavor, no matter what. A friend of mine who writes for a hip-hop website is easy for any music lover to connect with. I talk to him every time a new mix tape drops, debating which tracks are the most fire. Another friend works for a soccer analytics company; he tracks the most popular sport in the world. I talk to him every time I’m watching an entertaining game or have a question about a soccer article I’ve read. But not many of my friends have burning questions about isotope geochemistry. The rare conversations we have had about protactinium have tended to be short and one-sided. I love talking about my research. I love learning about other peoples’ research. On land, I have limited opportunity to have these conversations.
On the ship, these conversations are nonstop. Oceanography is what the scientists on board all have in common – how could we not constantly talk about it? I might not know what someone’s favorite color is, or what town they grew up in. But I could probably give a pretty solid explanation of the questions they’re trying to answer with their research. I’ve detailed the systematics of protactinium and thorium isotopes countless times to other scientists on board and gotten genuinely interested responses, rather than blank stares. I began to understand what my colleague meant about interacting with strangers being the most difficult thing about returning to land. Returning to land will mean returning to the real world. There, my research and much of my identity will get suppressed until I can find my way back to the company of fellow scientists.
But as I had that realization, I was immediately distracted. The manganese nodules had made their first appearance within the deep sediment where they didn’t belong. Reality on land could wait. My colleague and I began to volley back and forth ideas about how they could have been emplaced so deep, and what experiments we could design to test our hypotheses. This is my beautiful reality at sea.
By Frankie Pavia
We’ve just completed our first full station and are remarkably pleased with the results. We collected 8 seawater samples to measure helium isotopes; 20 to measure thorium and protactinium isotopes; 7 in-situ pump filters to measure particulate thorium and protactinium isotopes; 6 manganese oxides cartridges that were attached to the pumps to measure actinium and radium isotopes; and 1 box core of the ocean floor to measure sedimentary thorium and protactinium isotopes. I was going to make this paragraph into the Twelve Days of Christmas song, but 7 pumps-a-pumping doesn’t really roll off the tongue that well.
What all this means is that the first station was a smashing success for us. The only thing that didn’t quite go as planned was the nine-meter-long gravity corer coming up empty. We suspect it may have been due to the corer not being able to penetrate the hard carbonate layer we saw–about 15 centimeters thick in our box core. Nonetheless, we are delighted.
We were especially pleased that our in-situ pumps worked. We arrived on the cruise with the knowledge that the pumps would be there, but figured that somebody would be an expert on how to program them, maintain them and operate them. The pumps are essentially motors hung on a line deep in the water, drawing thousands of liters water through a filter, catching the ocean’s suspended particles.
After a week of poring over the manual, we were finally ready to deploy the pumps. It would take them 2.5 hours to descend to 3600 meters water depth, 6 hours of pumping, and 2.5 hours for the deepest pump to return. A convenient time to have them pump is overnight. Sleep is hard to come by while on station, so six hours of pumps pumping away at depth is a great excuse to scuttle off to bed.
We were pretty nervous as to whether they would actually work. We had invested a lot of time and energy getting them up and running. What a bummer it’d be if they spent six hours in the deep ocean not doing anything because I had accidentally programmed them to pump at the wrong time, or something. Our test run the previous day had been a bit spotty, too. The flow rate of the pumps had been something like 3 times lower than it should have been.
We woke up at 4 a.m. the next day to wait for the pumps to arrive back on deck, driven by caffeine and nervous energy. Christmas had been two days previous. On Christmas Eve the crew put on a terrific party in the hangar, and the pumps had been decorated with big red ribbons. We were about to find out whether the pumps were a present we actually wanted, or if they were one of those fancy battery-powered toys you get with a list of parts that has three missing and ends up never working.
All the pumps have names. We were able to name the four new pumps after ourselves, while the other four pumps already names. Claudia, Bernhard, Sebastian, Frankie, Laura, Frauke, Jimmy and Hulda. They all seemed to have a little personality too – especially the old ones, Laura, Frauke, Jimmy, and Hulda. Parts of Laura were backwards, Hulda’s screws refused to come loose, Jimmy’s pump head had missing pieces.
Claudia was the first to arrive at the surface. Immediately upon getting her out of the water, we put a shower cap over the filter holder to protect the filter from contamination by atmospheric aerosols and any dust floating around the hangar. We pumped the remaining water from the bottom through the filter, removed the filter holder and brought it to the lab. We carefully unscrewed the top, opened it up, and…
The filter was covered in particles! One by one, the pumps came up with filters that were coated by an even distribution of particles. Everything worked perfectly. Even Laura, Hulda, and Jimmy, though they were stubborn above water, did everything they were supposed to do once they were submerged.
We plan to measure protactinium and thorium isotopes on the particles to learn about the kinetics of particle movement in the ocean – sinking rates, absorption coefficients for trace metals, and export fluxes. Particles are the vectors that move elements out of the surface ocean, so studying their characteristics will be crucial for understanding how things like carbon and iron are pumped and exported to the deep.
Functional pumps meant that it was a happy Christmas for us. The next full station starts this afternoon. We’ll spend 42 hours sitting in one place, measuring dissolved, particulate, and sediment samples. Yesterday we had to change all the batteries on the pumps. Each pump requires 24 D batteries per deployment, and uses them all. So for every cast of 8 pumps, we use 192 D batteries. We’ll send the pumps out tonight and retrieve them at 4 a.m. again tomorrow morning.
We’re hoping these pumps are gifts that keep on giving.
Yesterday morning the Gould returned to Palmer Station, which means that it’s time for Jamie and I to take off. I’m looking forward to getting home and working through all the data we’ve collected (and who wouldn’t want to spend Christmas sick in the Drake Passage?), but sad to be leaving at an ecologically interesting point in the season. After a particularly windy spring we’ve had a week of calm conditions. As expected this resulted in a huge increase in primary production. The water at our regular sampling stations has turned green almost overnight. In an ideal world we would have seen those conditions two weeks ago, at the height of our sampling, but there’s no predicting the timing of these events! Consistent with what we’ve seen in the minor blooms all season this major bloom is composed mostly of Chaeotoceros. Instead of short chains however, we’ve got dense chains of many tens of cells. If these calm conditions persist a little longer it bodes well for the krill (and everything else) this season. To keep track of what the Palmer LTER group is up to for the remainder of the season you can check out Nicole Couto’s blog here.
All in all it was an extremely busy and productive early season. Many thanks to everyone at Palmer Station for making it happen!