One source is sediment cores. "Sediment," in this case, means mud. A greenish-brownish oozy sort of mud that is currently stuck under my fingernails and in my hair. Some of that mud is 11,000 years old!
We spent most of the day getting a 4-meter long segment of mud from the seafloor and analyzing it. First, the core has to be described and photographed. Then we put some of the mud away so that we will have a record of the core. Remember those PVC pipes that I was slicing up with the bandsaw? Now we're using them!
We also took samples of the mud every 5 cm at put it into vials. The photo shows the places where we took the mud. After that, we put big syringes into the remaining mud so it could be studied too.
Everything is labeled very carefully so that when the samples are analyzed, we'll know exactly where they came from. Within a few days, we'll have a whole story of how the landscape in this part of Antarctica has changed over time. This core is deeper than any other in the area, so we'll be able to add to the story told by other cores and extend it back an additional