Wednesday, January 20, 2010

Core on the floor!

After some problems with APC coring (see drilling equipment class a few posts ago), we have our first core on deck as of this morning. I woke up with the message "core on the floor" on the PA system at 11 AM. Yesterday two attempts were made to launch the piston corer, but one shoe broke off, and the other bent so severely that the drillers couldn't pull it up through the drill pipe. The only solution was to pull all the pipe out and to try again with a rotary core barrel. It was pretty obvious that there was something very hard out there near the sea floor and this morning we found out what it was: gravel. The first core was cut into sections and is currently sitting in the core lab to equilibrate, so that the physical properties will not change while these are measured on the core. After the physical properties have been measured, the core will be split into two halves, and we, the sedimentologists, get to describe the cut face of one half. The other half will be sampled.
The core comes out of the core barrel in a 9 m long plastic tube (see photo taken on "the catwalk"). There the length of the core is measured and it is cut into 1.5 m long sections by the curator and his team. In the photo, you can see co-chief scientist Carlota Escutia (in front) and the core techs placing the second core in the holders. This happened just now. The core feels quite cold when it comes up. This is the main reason that it is necessary to hold the core in a rack in the core lab for a while so that it can get to room temperature first. Temperature effects physical properties, such as density. You may know that most materials expand when they heat up, and this reduces their density.

P.S. For all you teachers and professors out there: feel free to use anything from this blog for your classes. This is for you and your students, so that you can take part in the experience! Feel free to ask questions via the comments as well. I will try to answer them as well as I can or get an expert from the rest of the science team to do it if I can't. Additional resources can be found on

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