Trace Elements of sediment core ML1208-16BB from central equatorial Pacific

Quantitative constraints on deep ocean carbonate chemistry are critical for understanding the processes responsible for glacial-interglacial changes in atmospheric pCO2 and the ocean feedbacks that amplify carbon cycle change. Here, we present a new, millennially-resolved, B/Ca-based record of carbonate ion concentration (∆[CO32-]), measured on C. wullerstorfi, from central equatorial Pacific site ML1208-16BB spanning the last 35 ka. This site, bathed by Pacific Deep Water, reveals a ~24 ± 7 µmol/kg rise in deep ocean [CO32-] between ~20 and 10 ka, a larger change than previously reconstructed from sites in the western equatorial Pacific and those in the central equatorial Pacific bathed by Lower Circumpolar Deep Water.