I’ve been hearing about the process for quite some time now, but that is still nothing compared to seeing the actual core coming up and being handled.
Today I’ll talk about what happens to the core before it’s cut. It’s almost like a dance with everyone waiting for their turn with a favored partner. First the core comes on to the catwalk and gets cut into sections and capped.
After it is finished on the catwalk it goes inside and gets labeled and gets a number engraved on the core liner (the plastic tube around the core). After that it has to sit on the rack for about 4 hours to warm up. The instruments can’t handle the cold from the deep ocean, so the cores have to come to room temperature before they can be tested. The first test measures density and magnetic susceptibility. (someone please correct me if I got that wrong!)
The next test is thermal conductivity. In other words, how easily does heat travel through the core.
After Thermal Conductivity, it’s time to cut the core! Finally! The machine that is used to cut “soft” (sedimentary) rocks has a wire almost like a piano wire and a track pulls the wire through the core, almost like a cheese slicer. Sometimes the endcaps can come loose after being pulled on by the wire. The second picture shows Johanna using a sonic welder to melt the plastic endcap back onto the core. It’s a neat tool. It uses sound waves to vibrate the plastic molecules into a liquid. It doesn’t use heat!
And finally we have a cut core. One half is the “Working Half” that scientists will take their samples from. It will get all kinds of pieces gouged out of it. You’ll see that later. The second half is the “Archive Half” and it goes in to a core repository – kind of like a library for cores. It will stay there for years so that other scientists working on the same thing can look at it.