Models and Mud: It’s a ‘Mud Cruise’

Posted for Saturday, May 22

Our cruise is a ‘mud cruise’ because we are taking sediment samples onto the boat. 

 Today we went out coring all day. Basically you lower the multi-corer down to the seafloor to collect sediment cores. (I tried to attach pictures, but I can’t load them with the available internet connection – I’ll try again later). It works well if the seabed is mud, but isn’t able to get sandy cores that well because the sand isn’t as cohesive as the mud, the multi-corer can’t create a good suction.

Back on the boat, the cores are split up and ‘operated on’ for lack of a better word. One core gets x-rayed. Another is split up by depth (in a couple centimeter bins) and stored in baggies until we get back home and can do radioisotope analyses (measuring how fast unstable elements decay). A third is used for sieving and looking for animals that live in the mud. A fourth is used for erosion experiments (more on that later!).

At the same time we cored, we were also ‘CTD-ing’, or using a CTD. CTD stands for conductivity (used to measure salinity), temperature and depth. A CTD measures those three things plus other water properties including turbidity, light attenuation, and many more water properties. We’ve been seeing a lot of mixing, with water properties being the similar at the top and bottom of the water column – we haven’t found the river plume, yet.