22 March, 2001

42 24 Longitude

-56 49 Latitude

Katharine

Hi, my name is Katharine. I am a student at Middlebury College in Vermont. Three years ago at Middlebury, I went to a slide show about research on the Antarctic Peninsula given by two students and a geology professor. I was so amazed by the hands on science and the beautiful pictures of icebergs they saw that I decided I wanted to go there too if I could. Now, during my senior year at Middlebury, I was able to come down south to the ice with that same geology professor, Pat Manley, except this time we went to the opposite side of the continent.

Although the students get to do many different things on board, I am mainly responsible for helping with the 10-ft long Kasten Cores that come up on deck. During the entire two months out here we have recovered 29 Kasten Cores and 3 Jumbo Kasten Cores (these are double the length of one Kasten Core 20 feet long!). As the Kasten Core is coming up from the bottom of the ocean, I get ready to go outside. In my hard hat and steel toed boots I go out to the back deck with the tools and someone else who is also on Kasten Core duty. Since I am on the night shift, it is usually dark outside and very cold, but sometimes the core happens to come up during sunrise which is absolutely spectacular! A few times there were even penguins sitting on nearby icebergs watching us. When the core comes out of the water, the marine techs lay it on the deck and we open the metal panels in the top of the rectangular core to find the top of the mud and get the excess water out.

After carrying the heavy core into the lab and getting it set up for one of the main scientists to describe and photograph, I get ready to start measuring the physical properties of the core. First I set up the Electrical Resistivity (ER) probe to measure the pore water content of the mud every 2 cm down the core. This unit was actually built by the two students who went to the Antarctic Peninsula 3 years ago. Observing the downcore variations produced by this instrument is an effective method for making correlations between different cores. After this, it is my job to measure the magnetic susceptibility on the core with a very sensitive surface-scanning sensor. This is the white probe that you see me using in the pictures. I have to record the values for every centimeter. Magnetic susceptibility gives us an idea of how many magnetic parcticles there are in the sediment, which is indicative of the sediment source (land erosion or biological activity in the ocean). Along with the ER, we can use these records to learn more about similarities in past climate change cycles around Antarctica.

Finally, I take samples from the core to take back to Middlebury to study the actual water content and pore space between sediment parcticles. To do this we brought 3200 vials with us but we got so many cores that we ended up running out of vials. We had to make do with whatever we could find for the last Jumbo Kasten Core (see picture of vials). It takes a few hundred vials to take these samples on each core which means I will have a lot of work to do to process them when I get home! All this sampling is definitely worth it because of the high quality of the cores we took and because of the amazing things we have been able to do down here in the Southern Ocean.

Katharine Burgdorff