GLACIAL/INTERGLACIAL EXPORT PRODUCTION IN THE SUBANTARCTIC SOUTH PACIFIC

The Subantarctic South Pacific is an area of the ocean that is crucial to the understanding of both glacial climate and paleoproductivity. Unfortunately, few studies have investigated the central South Pacific because it is so remote. MV0502-04JC was recovered from the Subantarctic South Pacific in February-March 2005 at 50S. The 17m core was recovered from a water depth of 4203m, and we sampled 4JC at sample resolution of 5 cm. The core will be used to evaluate the relationships between paleo-productivity and climate state and provides a nearly continuous record of sedimentation over the last 1 Ma. Phosphorus (P) is an important nutrient that likely limits productivity in the oceans on geologic time scales, and records of P burial can be useful when trying to reconstruct paleo-export production. Average P concentrations for marine sediments are ~30μmol/g. Average P concentrations at 4JC are typically low at the top of the core and increase steadily with depth to a maximum value of 50μmol/g. P/Ti ratios, which are a proxy for export production have clear, distinct maxima that indicate export production has varied significantly over the last 1 Ma. This research will shed light on climate system dynamics in the Subantarctic Pacific Ocean, including paleoproductivity and glacial/interglacial climate.