Thursday, February 25, 2010, 4:30PM - 5:30PM
In a paper published in Paleoceanography (2005) entitiled “Glacial water mass geometry and the distribution of δ13C of ΣCO2 in the western Atlantic Ocean” Curry and Oppo used δ13C of benthic foraminifera to reconstruct glacial deepwater geometry in the western Atlantic. However, there remains little data from ~30S - ~25N at water depths shallower than 2km, which is needed to reconstruct the northward penetration of the glacial equivalent of Antarctic Intermediate Water. The main stated goal of this cruise located in the western tropical Atlantic was to collect cores to fill that gap. The cruise was a combination of surveying (3.5 kHz and swath bathymetry) to identify good coring locations, coring (multicore for surface sediment, gravity core for Holocene sediment, and long piston core for older sediment), and water collection (for 18O, C13, salinity, trace elements, and Nd isotopes.) We also collected large volume water samples for C14 at one station. In the ship’s lab, we collected multi-sensor track data on the gravity and long cores, and preformed some initial biostratigraphy that can be tied back to the MST data. Additionally, we slabbed multicore tops to preserve them for live benthic analyses and archived all the rest. During my talk I will present photos of the coring operations and labwork at sea, and further discuss the motivation, materials and methods employed on the RV Knorr. (And I will also explain why our cruise track looks like an Etch-A-Sketch).