Anyone who has gone in the field regularly, however, will tell you that no amount of planning will prevent the unexpected from happening. This is when creativity can make or break an experiment. One instance when creativity proved to be useful was on a recent research expedition on board the RV SONNE. After almost 7 weeks at sea, sampling supplies on ship were running low. To sample sediment cores, cut-off syringes were used to draw some sediment and were then capped. Unfortunately, we ran out of caps and cores were still being collected.

As I was thinking of a simple way to cap the syringes without contaminating the sediment with the glue from the tape, it occurred to me that lab gloves ought to be made of material that would not contaminate the samples. We ended up cutting the fingers of some lab gloves (we had plenty of those), in order to pull them over the syringes and secure them with tape. This was simple enough and served our purpose!

The true syringe lid on the left, the improvised lid on the right.

Just by looking at the cores and feeling the mud we can identify boundary and redox layers as well as differences in grain size. But to find out more, we take samples of these cores for future analysis.

If you like getting muddy, then you’ll love sediment work! To sub-sample these cores we remove a tube filled with sediment from the MUC and place it on a stand. Once the core is on the stand we can move it down centimeter-by-centimeter revealing 1 cm of sediment at a time and scraping it off. For the first few really wet centimeters we put the sub-samples in a glass jar. After that we fill syringes with sediment every few centimeters until we get to the end of the core. Since we’re dealing with mud, and not water, we have to cut the tip off the syringe and then push it into the sediment core to get our sub-sample. Once we’ve taken these sub-samples we can look at things like nitrogen isotopes, sediment grain size, and multiple other parameters. Ultimately, this information from the sediment helps us reveal a little bit more about what’s happening in the ocean above, both today and in the past.

An empty MUC on the ship before deployment

The MUC coming up!

Cores filled with sediment

Tip-less syringe to be filled with sediment

Putting the core on to the core stand

Sampling the first few muddy centimeters

Sampling with the tip-less syringe

The research work being conducted is, in general, geoscience. What does this mean to student scientists onboard? More often than not it means getting muddy. Inevitably on a geoscience cruise, some amount of mud will be brought up from the seafloor and processed. The fate of the mud varies and depends on who wants it and for what, which often determines how it was retrieved from seafloor. Processing onboard can involve splitting, cutting, sub-sampling mud/porewater, logging, and always labeling. You can see Liz sub-sampling a multi-corer tube in 1 cm slices and using a modified syringe in the pictures below.

Every now and then, crafty professors manage to escape the daily grind at the office and actually make it out on one of their cruises. Markus gets points for craftiness here: not only has he managed to make it out on a cruise, he’s selected a tropical location and is keeping his hands clean… or at least mud-free! You can see Markus sampling seawater from niskin bottles in a CTD rosette in the pictures below. He is hoping water column profiles of nutrient concentrations and the isotopic composition of nitrate will help explain water mass distributions in the study area, and aid in ground-truthing the interpretation of paleoceanographic proxy records.

This cruise (SO-228) combines three cruise proposals for research in the Western Pacific. Read more about the proposed research and cruise plans on the MARUM Bremen University website.

In addition to being on one of the best sediment coring vessels in the world, I got to stay at the Charles Darwin Research Foundation in Puerto Ayora where I swam with endemic marine iguanas and tried to fall asleep to the surprisingly loud sound of mating Galápagos giant tortoises.