Search for a glacial-age (14)C-depleted ocean reservoir

Measurements of the radiocarbon age difference between mixed benthic foraminifera and several coexisting planktic entities were made in hopes of finding evidence for the existence of an isolated glacial-age abyssal ocean reservoir whose demise would explain the large drops in the (14)C to C ratio in atmosphere and surface ocean carbon which occurred during the period of deglaciation. Forty-six new radiocarbon results were obtained at seven depths covering the full range of glacial time (i.e., similar to 27 to 15 (14)C kyrs) from an equatorial Pacific sediment core at 4.4-km water depth. Even though age reversals for foraminifera (but not for coccoliths) at two of the eight depths and large age differences between G. sacculifer and three submixed-layer planktic species mar this data set, there remains little likelihood that such a reservoir existed. Citation: Broecker, W., and E. Clark (2010), Search for a glacial-age (14)C-depleted ocean reservoir, Geophys. Res. Lett., 37, L13606, doi: 10.1029/2010GL043969.