EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Release of old carbon from the deep South Pacific during the last deglaciation

Yuhao Dai1,3, Jimin Yu1, and Patrick Rafter2
Yuhao Dai et al.
  • 1Research School of Earth Sciences, The Australian National University, Canberra, ACT, Australia
  • 2Department of Earth System Science, University of California, Irvine, CA, USA
  • 3Lund University, Department of Geology, Sweden (

The release of old carbon via the Southern Ocean has been thought to contribute to the last deglacial atmospheric CO2 rise, but underlying processes are not fully understood, in part, due to insufficient high-fidelity radiocarbon (Δ14C) reconstructions minimally complicated by age models and release of “dead carbon”. Here, we present a new deep-water Δ14C record for a core located at 3.3 km water depth from the Southwest Pacific, based on a robust age model using planktonic Mg/Ca along with co-existing benthic 14C measurements. Our results confirm previous records that suggest enhanced ventilation in the Southern Ocean during Heinrich Stadial 1 and the Younger Dryas. For the first time, our data show a large Δ14C decline during the Antarctic Cold Reversal, indicating strengthened stratification in the deep South Pacific. Our results strongly support that the deep ocean supplied old carbon to the atmosphere during the last deglaciation.

How to cite: Dai, Y., Yu, J., and Rafter, P.: Release of old carbon from the deep South Pacific during the last deglaciation, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4230,, 2020

This abstract will not be presented.