Michael Evans Richard G. Fairbanks James L. Rubenstone 1998/10 World Data Center for Paleoclimatology Data Contribution Series 1998-035 Boulder World Data Center for Paleoclimatology, Boulder The following is excerpted from Evans et al., J.Geophys. Res., in review, 1998 (please see this paper for references made in this readme file): Proxy climate data derived from the isotopic composition and chemistry of aragonite formed by massive reef corals provide a supplementary data set for the study of the tropical near-surface climate [Cole et al., 1993; Dunbar et al., 1994; Linsley et al., 1994; Tudhope et al., 1995; Charles et al., 1997]. Given constant sea water o18 and biological processes, variability in the oxygen isotopic composition (o18) of coralline aragonite is a function of the sea surface temperature in which the coral secreted its skeleton [Epstein et al., 1953; Weber and Woodhead, 1972; McConnaughey, 1989]. However, coral o18 also records changes in the o18 of sea water [Cole et al., 1993; Linsley et al., 1994; McCulloch et al., 1994] if freshwater flux variance is significant. The Strontium:Calcium (Sr/Ca) ratio in corals has been shown to be a function of sea surface temperature as well, with minimal sea water Sr/Ca influence [Weber, 1973; Schneider and Smith, 1979; Beck et al., 1992; DeVilliers et al., 1994; Shen et al., 1996]. Application of these two proxy measurements in tandem has been used to distinguish sea water o18 and sea surface temperature anomalies recorded on the Great Barrier Reef during the 1982-3 El Nino-Southern Oscillation (ENSO) event [McCulloch et al., 1994]. We made measurements of stable isotopic composition (o18 and c13) and Sr/Ca on a coral collected live from Kiritimati (Christmas) Island (157.3 W, 2 N), in the Republic of Kiribati. Kiritimati lies at the eastern edge of the western Pacific warm pool and just west of the NINO3 box (Fig. 1). The seasonal range of sea surface temperature (SST) is less than 1.2 degrees C. Because the seasonal cycle is modest, ENSO-induced warm and cold phase sea surface temperature anomalies of +/-3 degrees C are prominent [Bjerknes, 1969; Wyrtki, 1975; Wyrtki, 1985; Philander, 1990]. By contrast, ENSO-driven precipitation anomalies are moderate in magnitude and brief in duration, creating a minor change in sea water o18 due to enhanced rainfall [Ropelewski and Halpert, 1987] and eastward advection of lower salinity water [Picaut et al., 1996]. Thus, Kiritimati is an ideal location from which to monitor the thermal signal associated with the full ENSO cycle and should record features similar to those in the NINO3 region. Data and Methods: Stable isotope data Coral PP7-3 was collected live and cored at South West Point, Kiritimati Island, at 9 meters depth in March 1994. The coral has been identified as Porites sp., probably P. australiensis, possibly P. lobata [D. Potts, UCSC, pers. comm.]. The core was slabbed along the growth axis and X-radiographed for densitometry study; slabs were then ultrasonically cleaned in de-ionized water and dried at 50 degrees C prior to sampling. Samples for oxygen and carbon isotope analyses were drilled from the slab at 0.5 mm intervals starting from just below the most recent growth and extending to a maximum depth of 1004 mm. A precise age model was recoverable for the upper 839.5 mm. Samples were drilled from lines chosen parallel to the axis of maximum growth to avoid non-temporal (i.e. potential differential growth-related) isotopic effects [McConnaughey, 1989]. X-ray diffraction analyses of drilled and chipped coral aragonite verify that samples were 100% aragonite after drilling. Sequential isotopic analyses were made using a Finnigan MAT-251 gas source mass spectrometer coupled to a Carousel-48 automated sample preparation device. Measurement precisions (1-sigma) were +/-0.06 per mil and +/- 0.04 per mil for o18 and c13 analyses, based on analysis of a lab standard; sample replication over the 1981-1987 period (see section on Sr/Ca data below) gives an external precision of +/- 0.09 per mil in the o18 time series shown in Fig. 2. All stable isotope measurements are reported Paleoclimatic Research G2069 World Data Center for Paleoclimatology, Boulder http://www.ngdc.noaa.gov/paleo/corals.html 1 1938 1993 Publication Date Complete None Planned -157.3 -157.3 2.0 2.0 CoRIS Theme Keywords Version 1.0 EARTH SCIENCE > Paleoclimate > Coral Records > delta 18O EARTH SCIENCE > Paleoclimate > Coral Records > delta 13C EARTH SCIENCE > Paleoclimate > Coral Records > Sr/Ca EARTH SCIENCE > Paleoclimate > Coral Records > temperature Numeric Data Sets > Paleoclimatology EARTH SCIENCE > Atmosphere > Atmospheric Phenomena > El Nino (ENSO) CoRIS Place Keywords Version 1.0 OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Line Islands > Kiritimati ( Christmas Island ) (02N157W0001) COUNTRY/TERRITORY > Kiribati > Kiritimati > Kiritimati ( Christmas Island ) (02N157W0001) CoRIS Temporal Keywords Version 1.0 Holocene, Modern None Please cite original reference when using this data Evans, M.N., R.G. Fairbanks and J.L. Rubenstone, A Proxy Index of ENSO Teleconnections, Nature 394:732-733, 1998. and Evans, M.N., R.G. Fairbanks and J.L. Rubenstone, The Thermal Oceanographic Signal of ENSO Constructed from a Kiritimati Island Coral, J. Geophys. Res., 1998, in review; preprint available at http://rainbow.ldeo.columbia.edu/~mevans/preprints/thermal_signal/ coral variable coral variable coral variable del13C delta 13C (per mil) Craig, H., 1957. Isotopic standards for mass spectrometric analysis of carbon dioxide. Geochimica Cosmochimica Acta, 12:113-140; Fairbanks, R.G., and R.E. Dodge, Annual periodicity of the O-18/O-16 and C-13/C-12 ratios in the coral Montastrea annularis, Geochimica et Cosmochimica Acta, 43, 1979. unknown unknown per mil 0.01 del18O delta 18O (per mil) relative to PDB Craig, H., 1957. Isotopic standards for mass spectrometric analysis of carbon dioxide. Geochimica Cosmochimica Acta, 12:113-140 unknown unknown per mil 0.01 d18OAnom delta 18O (per mil) anomaly relative to the 1981-1986 mean Evans, M.N., R.G. Fairbanks and J.L. Rubenstone, A Proxy Index of ENSO Teleconnections, Nature 394:732-733, 1998. unknown unknown per mil .01 SrCa Sr/Ca Ratio Beck, J. W., R. L. Edwards, E. Ito, F. Taylor, J. Recy, F. Rougerie, P. Joannot, and C. Henin, 1992, Sea surface temperature from coral strotium/calcium ratios: Science, v. 257, p. 644-647; DeVilliers, S., G. T. Shen, and B. K. Nelson, 1994, Sr/Ca paleothermometry in corals: method calibration and evaluation of Sr/Ca (seawater) and interspecies variability: Geochimica Cosmochimica Acta, v. 58, p. 197-208. unknown unknown mmol/mol 0.015 SrCaAnom Sr/Ca Ratio anomaly relative to the 1981-1986 mean Evans, M.N., R.G. Fairbanks and J.L. Rubenstone, A Proxy Index of ENSO Teleconnections, Nature 394:732-733, 1998. unknown unknown mmol/mol 0.015 NOAA Paleoclimatology Program Bruce Bauer Data Manager Mailing Address

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Boulder CO 80305-3328 U.S.A. (303) 497-6160 (303) 497-6958 (303) 497-6513 paleo@ngdc.noaa.gov 9-5 MST Monday-Friday Disclaimer- While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any erro ASCII ftp://ftp.ngdc.noaa.gov/paleo/coral/east_pacific/kiritimati_1998.txt ftp://ftp.ngdc.noaa.gov/paleo/coral/east_pacific/kiritimati_1998.xml Data can be obtained from http://www.ngdc.noaa.gov/paleo/data.html and via anonymous ftp to ftp.ngdc.noaa.gov. Diskette and paper copies may be obtained by mail. Diskette cpio On-line data are available free of charge, other forms are available for the cost of reproduction Contact the data center to order paper copies of the data 4 days 20011003 NOAA Paleoclimatology Program Carissa Carter c/o Data Manager Mailing Address

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Boulder CO 80305-3328 U.S.A. (303) 497-6160 (303) 497-6958 (303) 497-6513 carissa.l.carter@noaa.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 No Constraints No Constraints 3811 162 1000000161 20011113 20011220