The sediment-laden ice blocks were rectangular and approximately 1 x 0.4 x 0.25 m in size. The ice blocks were free of air bubbles and each contained enough Bay of Fundy mud to make the ice blocks slightly more dense than seawater. On average, each ice block weighed 135-140 kg and contained about 27 kg of dried mud. The ice blocks were contained within netting just below the surface and instrumented with GPS loggers, PT sensors (above and below), and an HD video camera.2

The sediment-laden ice blocks were deployed in sets of three. The location and timing within the tidal cycle of each deployment was varied. The ice blocks were deployed in the Minas Passage near or immediately after low water, in Cobequid Bay on the ebb, and in the middle of the basin on the flood.

During the deployments, a small boat was used to monitor each ice block drifter. A frame instrumented with another HD video camera and scaling lasers was lowered next to each ice block periodically during the melt. Melt rate will be estimated based on recorded changes in ice block size and compared with model results.

Making ready on deck.

Deploying an ice drifter.

Small boat ready to chase the 3 ice drifters that were just deployed.

Ice drifters deployed from the CCGS Hudson.

Monitoring the ice drifters with a small boat.

Bringing the recovered gear back to the CCGS Hudson.

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.