There are days when pulling cores of mud out of the Gulf of Mexico and processing them might not seem all that thrilling. We, aboard the research vessel Ocean Veritas, heartily disagree.
Our Chief Scientist Ian Hartwell is very interested in an odd trend we’ve noticed the closer we sample to the well head: there is an ever-increasing layer of strange, fluffy, brown mud in our sediment cores. This is the opposite of what we think should be happening. Typically, as we sample deeper offshore, we would expect the soft, mud layer on the sea floor to decrease; it settles out as energy from the rivers dissipates. And, at first, this is what we were getting: as we sampled further from shore, the cores came up with less and less sediment because we were reaching the more compact clay layer under the mud more quickly and the cores could not sink down as deep.
But, at the last several stations, the fluffy mud layer grew, instead of decreased, as we got closer to the well head. There were no visible oil globules in the mud and we only saw a slight sheen in the cores at the actual well head site. Also, as opposed to the normal muddy layer, which is similar to pudding in consistency, this sediment was more loose with the first centimeter or so practically floating near the surface of the sample. It’s too soon to make any conclusions about what this means, but it is an interesting observation.
And then there are the strange and curious deep sea creatures that occasionally get collected along with the sediment. When we take our sediment samples, the multi-corer is lowered down very slowly by the winch. The apparatus settles gently on the sea floor (so that there is minimal disruption to the loose top layer of sediment) and then the tubes drop straight down into the mud. Each tube has a lid. When they close, anything directly above the mud will get caught if it doesn’t get out of the way fast enough. If the creatures are in one of the five cores that we use for chemistry analysis we just let the creatures go. We also let them go if they are clearly pelagic (meaning that they live in the water column).
See, never a dull moment when it comes to sea mud.