Late Pliocene variability of the Agulhas Current: Planktic foraminiferal records from southwest Indian Ocean

The Pliocene climate was punctuated by many global glacial events, which set the stage for the Quaternary glaciations. The Late Pliocene witnessed two major glacial events, at 3.3 and 2.7 Ma. These events changed not only the dynamics of the ice sheets and global climate but also the ocean circulation patterns. The present work aims to reconstruct the variations in the strength of the Agulhas Current (AC) during the Late Pliocene on the basis of the planktic foraminiferal census and stable oxygen isotope data from IODP Hole U1474A. The relative abundance of the Indian Ocean Group (IOG), the Southern Ocean Group (SOG) and the productivity indicators (PI) show significant variations, recording a change in the AC strength. The stable oxygen isotope also corroborates the variation in the Sea Surface Temperature (SST), in response to the AC strength. The records indicate five episodes of weakening of the AC during the Late Pliocene, which were in response tothe waxing Antarctic Ice Sheet leading to the northward migration of the polar fronts.