title: Radiocarbon constraints on the extent and evolution of the South Pacific glacial carbon pool.
abstract: During the last deglaciation, the opposing patterns of atmospheric CO2 and radiocarbon activities (Δ(14)C) suggest the release of (14)C-depleted CO2 from old carbon reservoirs. Although evidences point to the deep Pacific as a major reservoir of this (14)C-depleted carbon, its extent and evolution still need to be constrained. Here we use sediment cores retrieved along a South Pacific transect to reconstruct the spatio-temporal evolution of Δ(14)C over the last 30,000 years. In ∼2,500-3,600 m water depth, we find (14)C-depleted deep waters with a maximum glacial offset to atmospheric (14)C (ΔΔ(14)C=-1,000‰). Using a box model, we test the hypothesis that these low values might have been caused by an interaction of aging and hydrothermal CO2 influx. We observe a rejuvenation of circumpolar deep waters synchronous and potentially contributing to the initial deglacial rise in atmospheric CO2. These findings constrain parts of the glacial carbon pool to the deep South Pacific.
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Department for Marine Geology, PO Box 120161, Bremerhaven 27515, Germany.
authors.forename: T A
authors.initials: TA
authors.lastname: Ronge
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Department for Marine Geology, PO Box 120161, Bremerhaven 27515, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Tiedemann
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Department for Marine Geology, PO Box 120161, Bremerhaven 27515, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Lamy
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Department for Marine Geology, PO Box 120161, Bremerhaven 27515, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Köhler
authors.affiliation: School of Geography, Environment and Earth Sciences, Victoria University of Wellington, PO Box 600, 6012 Wellington, New Zealand.
authors.forename: B V
authors.initials: BV
authors.lastname: Alloway
authors.affiliation: GAIA-Antartica, Universidad de Magallanes, Punta Arenas 01855, Chile.
authors.forename: R
authors.initials: R
authors.lastname: De Pol-Holz
authors.affiliation: Max Planck Research Group-Marine Isotope Geochemistry, Institute for Chemistry and Biology of the Marine Environment, Department of Marine Isotope Geochemistry, Carl von Ossietzky University, PO Box 2503, Oldenburg 26111, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Pahnke
authors.affiliation: School of Physical Science, Department of Earth Science, University of California, Irvine, California 92697-4675, USA.
authors.forename: J
authors.initials: J
authors.lastname: Southon
authors.affiliation: Laboratory of Ion Beam Physics (HPK), Eidgenössische Technische Hochschule, Schafmattstrasse 20, Zürich 8093, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Wacker