Phytoplankton response to changes in the chemistry of the Eastern Equatorial Pacific waters during Termination II

12th International Conference on Paleoceanography (ICP12), 29 August - 2 September 2016, UtrechtResearch on the physical and biological processes controlling the transitions from glacial to interglacial periods has mostly focused on the most recent Termination (TI). However, studying previous deglaciations should provide further insights into the mechanisms involved during these transitions. In this study, we focus on the penultimate deglaciation in the Eastern Equatorial Pacific (EEP), a strategic location under the influence of upwelled nutrient-rich waters and a tight link with the Southern Ocean (SO) through the advection of intermediate waters. We present a multiproxy record of surface ocean productivity, dust inputs and thermocline conditions across TII(110¿ 150 kyr BP). These new records will allow us to assess responses of the phytoplankton community to changes in the surface water chemistry. Our records suggest enhanced dust input and high primary productivity during the end of the penultimate glacial maximum. A prominent peak in diatom production at the middle of the transition points to the arrival of Si-rich waters to the EEP, which would have promoted the growth of these organisms. The coincidence of this peak with a minimum in the ¿13C signal of deep thermocline dwelling foraminifera from the same core, used as a proxy for the influence of subantarctic sourced waters, suggests that a silicic acid leakage from the SO through intermediate waters occurred during the TII, similar to what was reported in this area for TI (Calvo et al., 2011, PNAS)Peer Reviewe