HR: 09:30h
AN: PP31A-07    [PDF]
TI: A Coral Perspective on Holocene Climate Variability in the Western Pacific Warm Pool
AU: * Quinn, T M
EM: quinn@marine.usf.edu
AF: College of Marine Science, University of South Florida, 140 Seventh Avenue South, MSL 119, St. Petersburg, FL 33701 United States
AU: Taylor, F W
EM: fred@utig.ig.utexas.edu
AF: Institute for Geophysics, The John A. and Katherine G. Jackson School of Geosciences, The Univ. of Texas at Austin, 4412 Spicewood Springs Rd., Austin, TX 78759-8500 United States
AU: Edwards, R
EM: edwar001@umn.edu
AF: Department of Geology and Geophysics, University of Minnesota, 310 Pillsbury Drive Southeast, Minneapolis, MN 55455 United States
AU: Burr, G
EM: burr@physics.arizona.edu
AF: NSF Accelerator Facility, Department of Physics, University of Arizona, 1118 E. 4th Street, PO Box 210081, Tucson, AZ 85721 United States
AU: Cheng, H
EM: cheng021@umn.edu
AF: Department of Geology and Geophysics, University of Minnesota, 310 Pillsbury Drive Southeast, Minneapolis, MN 55455 United States
AU: Chen, Y
EM: ygchen@ccms.ntu.edu.tw
AF: Dept. of Geosciences, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Tapei, 106 Taiwan
AB: The Western Pacific Warm Pool (WPWP) serves as a heat engine for Earth's climate and as a major moisture source for its hydrological cycle. Studies of the instrumental record document that variations in the thermal and hydrologic properties of the WPWP have global ocean and atmospheric ramifications. Coral-based climate records have been exploited in other regions of the tropical oceans, yet such records are rare from the WPWP despite the fact that proxy climate records from the WPWP are recognized as among the most critical targets for future paleoclimate research. We have begun to address this recognized need by generating monthly resolved proxy records of thermal and hydrologic variability in the WPWP via paired determinations of $\delta^{18}$O and Sr/Ca in fossil corals from Tetepare, Western Solomon Islands ($8\deg$ 43' S; $157\deg$ 33' E). Thirty-three of the 54 fossil coral cores that were drilled and recovered have been dated by AMS $^{14}$C and by TIMS U-series techniques, and these corals range in age from 250 to 12,000 years old. Post-depositional alteration of our Holocene coral samples is judged to be minimal based on mineralogic (XRD), petrographic (SEM) and geochemical criteria (preservation of modern marine initial $\delta^{234}$U values). We have initially chosen to generate short time series ($\sim$4-5 years) of monthly $\delta^{18}$O and Sr/Ca variations from eight of the fossil corals and one nearby modern coral, although some of the cores contain well over 100 annual density bands. Annual cyclicity is observed in both $\delta^{18}$O and Sr/Ca in all of the time series generated to this point. Coral $\delta^{18}$O data show a general decrease in values through the Holocene from more enriched values of $\sim$-4.65$\permil$ at $\sim$10 Ka to a value of $\sim$-5.25$\permil$ in the modern coral. Coral Sr/Ca data indicate $\sim$$2\deg$C cooler SST w/r to modern values at 10,254$\pm$35 yr BP and $\sim$$1\deg$C warmer SST w/r to modern values at 3336$\pm$18 yr BP. The suite of fossil coral samples from Tetepare will ultimately yield multidecadal to centennial length proxy climate time series having subannual resolution that will be used to 1) determine how changes in the mean climate state of the tropics in the WPWP influence the nature of tropical climate variability on interannual to centennial timescales during the Holocene; and 2) define the timing and magnitude of abrupt transitions and extremes in Holocene climate in the WPWP and determine how these abrupt changes in the tropics are related to previously defined intervals of abrupt change in the extra-tropics.
DE: 1620 Climate dynamics (3309)
DE: 3309 Climatology (1620)
DE: 3344 Paleoclimatology
DE: 4215 Climate and interannual variability (3309)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting