I know I have already mentioned the pros and cons to working the night shift. Today I wanted to focus on the great experiences I have been having on recent night shifts.
Yesterday’s shift was the first time I was able to help extrude a core. Okay, I know some readers may be asking, “What is so exciting about that?” For one thing, it’s muddy, and I love playing in the mud (just ask my mom about my childhood hobbies). I also get to use some interesting tools that I would not normally handle. For example, there is a handheld tool specifically designed to cut PVC pipe by repeatedly scoring the surface of the PVC. It looks like a hook with a small pizza slicer attached. All cores are extruded on deck, which is another reason I really like this work, especially on a day like yesterday when it was bright, breezy and only slightly below freezing. I do have to put on a lot of extra gear (steel-toed boots, float coats, hard hats, leather insulated gloves), but it’s all worth it to be outside in the fresh air.
It’s a big operation to deploy, retrieve and extrude these cores. Jobs include: crane operator, one person to push the PVC lining through the metal outer shell, one person to guide the core onto a stand, one person to handle sampling tools, and one other person who does the actually cutting and labeling of the core. The core I helped out with was called a jumbo gravity core, or JGC for short.
The cores are labeled according to the cruise (ship and date of cruise) on which they were collected, core type, station and section (if it has to be cut up into more than one piece). See Tasha’s blog if you want to know more about the different types of cores marine geologists use. Here is an example: LMG 13-11 JGC6. LMG stands for Laurence M. Gould and 13-11 stands for 2013, and the 11th cruise the Gould has done this year. JGC stands for Jumbo Gravity Core. The number 6 means it was taken at station 6 along the cruise route. There are 3 sections of LMG 13-11 JGC 6, so this core will also be labeled section 1, 2 or 3 (example: LMG 13-11 JGC6 sec. 1). This system is how we refer to cores when labeling samples, referencing them in papers, etc. By knowing the formula, geologists can identify cores taken on many different cruises.
The most exciting part of this experience is knowing that the sediment we are bringing up is thousands of years old. When I am sampling a fresh core, I am one of the first people ever to touch that mud. I am still learning about what the sediment can tell us, but I am beginning to see a story forming. Amy and Amelia have taught us students how to observe and record characteristics such as color, texture, distinct layers, composition, and even smell. We also measure the magnetics of the core to get a rough idea of how much of the sediment is derived from terrestrial (land) sources and how much is derived from marine (ocean) sources. All of these characteristics help our science team piece together the oceanographic story of Antarctica over the past 10,000 years.
Coring was definitely the highlight of yesterday’s shift, but I was also treated to a beautiful sunrise and was able to take some nice photos. Again, this is one of the best parts about working the night shift. I get to watch the sun go down and come back up again 5 hours later. There really is nothing like watching the sun rise over snow-capped mountains and a sea covered with ice.