HR: 1340h
AN: PP23B-1425    [Abstracts]
TI: Decadal and Centennial Variability of Climate From Isotopic Records in a Galapagos Coral
AU: * Druffel, E R
EM: edruffel@uci.edu
AF: Dept. of Earth System Science, UC Irvine, Irvine, CA 92697 United States
AU: Griffin, S
EM: sgriffin@uci.edu
AF: Dept. of Earth System Science, UC Irvine, Irvine, CA 92697 United States
AU: Dunbar, R B
EM: dunbar@stanford.edu
AF: Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305 United States
AB: Radiocarbon and $\delta$$^{18}$O measurements of annual Galapagos coral bands will be presented for the period A.D. 1595 to 1954. Because radiocarbon ($^{14}$C) in the surface ocean has a long turnover time (10 years) with respect to exchange with atmospheric $^{14}$CO$_{2}$, $\Delta$$^{14}$C of dissolved inorganic carbon in surface seawater is a tracer of mixing between the surface and subsurface waters, or thermocline depth. A large shift in $\Delta$$^{14}$C values was observed around the beginning of the nineteenth century. A similar shift was not observed in a subtropical coral record from the southwest Pacific. Changes in circulation inferred from these data, and their implications for the regional net efflux of CO$_{2}$ from the eastern tropical Pacific to the atmosphere, will be discussed.
DE: 3344 Paleoclimatology
DE: 4215 Climate and interannual variability (3309)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting