A transient rise in tropical sea surface temperature during the Paleocene-Eocene Thermal Maximum

• Published in: Science
• Main Authors: J. C. Zachos, M. W. Wara, S. Bohaty, M. L. Delaney, A. Brill, T. J. Bralower, M.R. Petrizzo, I. Premoli-Silva
• Other Authors: J.C. Zacho, M.W. Wara, M.L. Delaney, T.J. Bralower
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2003
• Subjects: oceanic methane hydrate; planktonic-foraminifera; latest paleocene; atmospheric CO2; Settore GEO/01 - Paleontologia e Paleoecologia; Pacific; Methane hydrate; Planktonic foraminifera
• Online Access: http://hdl.handle.net/2434/458091; https://doi.org/10.1126/science.1090110

The Paleocene-Eocene Thermal Maximum (PETM) has been attributed to a rapid rise in greenhouse gas levels. If so, warming should have occurred at all latitudes, although amplified toward the poles. Existing records reveal an increase in high-latitude sea surface temperatures (SSTs) (8° to 10°C) and in bottom water temperatures (4° to 5°C). To date, however, the character of the tropical SST response during this event remains unconstrained. Here we address this deficiency by using paired oxygen isotope and minor element (magnesium/calcium) ratios of planktonic foraminifera from a tropical Pacific core to estimate changes in SST. Using mixed-layer foraminifera, we found that the combined proxies imply a 4° to 5°C rise in Pacific SST during the PETM. These results would necessitate a rise in atmospheric pCO 2 to levels three to four times as high as those estimated for the late Pateocene.