AMS-14C ages and calibrated calendar ages, reported as median probability ages. AMS 14C dating was performed at the Analytical Center for Environmental Science, Atmosphere and Ocean Research Institute, University of Tokyo, Japan. Ages were converted to calendar ages using the CALIB14 software (Stuiver and Reimer, 1993; doi:10.1017/S0033822200013904). We applied the MARINE20 calibration curve (Heaton et al., 2020; doi:10.1017/RDC.2020.68) and a local reservoir age correction of DR=-153 yrs (Druffel et al., 1999; doi10.1029/2019GL083149).