IODP Expedition 342 Sampling Party
I’m not sure why this event is called a sampling ‘party’, unless you considering extracting various-sized bits of mud from core several hours of day for a week to be a party. More like a sampling binge. That doesn’t mean it wasn’t a great experience, it definitely was. It was fantastic to reconnect with all the great colleagues and friends I made after two months on the JOIDES Resolution last summer. And, of course, a team of >30 scientists working in two shifts at 5-7 stations can get a lot of work done.
The sampling party is a critical component of any Integrated Ocean Drilling Project (IODP) expedition. After all, the whole point of an expedition is to acquire samples of material (sediment and/or rock) from the ocean floor and below. Although a tremendous amount of work is done on the ship as the cores are collected (see the expedition preliminary report here) the expedition itself is really just the beginning.
The overarching goal of Expedition 342 is to examine several of Earth’s climate events/transitions from the Paleogene period (~65 to 23 million years ago) at high resolution. That is, we already know quite a bit about events like the Paleocene-Eocene Thermal Maximum (PETM) and the Eocene-Oligocene transition; however, most records are at temporal resolutions that make it challenging to understand dynamics and effects at shorter timescales. These past events are like ‘experiments’ that the Earth conducted and we need to use them to better understand current, and possibly future, global change. Paleoclimatologists have been able to obtain higher resolution (thousands to tens of thousands of years) with archives from the past two million years (the Quaternary), so another way to put this is: we want to do Quaternary-style paleoclimate analysis on much older records. To make a long story short — this goal requires A LOT of samples. I’m not sure what the latest number is, but it’s something on the order of 50,000 total samples.
Although their is an overarching goal, each scientist has a specific request in terms of what time interval, and what resolution, and how much material they need. As a result, the sampling plan is highly coordinated and the cores are brought out in a systematic fashion to ensure samples are taken as efficiently as possible. (IODP staff are quite good at this.) What’s really great about the sampling party is that the entire science party pitches in. You don’t show up to get just your own samples and then take off. For example, several people on the other shift or working at another station would be taking my samples and I would be taking theirs. And the discussions during sampling were great — a mix of serious science with lots of joking around, which helped maintain some sanity while doing very repetitive tasks.
What’s next? Well, once we all get our samples into our respective labs the analysis will commence. The majority of these samples will be used to generate various isotope data that are useful as climate proxies. Others will be examining the paleobiology/paleoecology of the different types of microfossils and others still will examine ocean chemistry preserved in the sediment. I will be measuring grain size of the terrigenous (land-derived) fraction to better understand the history of the long-lived current that brought sediment to the site. I still have much work to do to get my lab fully operational and the methods perfected, but progress is being made.
Photos: Upper left — stacks of core in the refrigerator; Upper right — in the process of taking 30 cubic centimeter samples; Lower left — lobby of Bremen Core Repository; Lower right — what’s left of one of the cores after sampling. All photos taken by me with my iPhone.