Geochem lab: Heavy seas, tiny samples

Yesterday was a fun but tricky day in the geochemistry lab – it was time to start grinding up and weighing our sediment samples in order to look their chemical composition. Not easy to do in a storm! First up, we ground the samples using a pestle and mortar like you’d have in your kitchen at home. Next, the tricky bit: weighing a tiny amount of sample (around 10-15 mg) into a small tin capsule (see photo below), which is sitting on a small balance pan which is itself dangling inside the “microbalance”. All this is to be done with tweezers and without dropping your sample: it can be challenging enough on land, but much worse when the ship is moving as it was yesterday. Because the microbalance is so sensitive, we have to calculate our sample weight as a mean over around 3 minutes. The photo shows why: each time the ship moves up and down you can see the mass change. You need a strong stomach for this activity! With a great team effort (including help from Alison!) we’ve got all the samples racked up and ready to go: we’ll soon have data on the carbon, hydrogen, nitrogen, sulfur and carbonate contents of the cores. Watch this space 🙂