Kiritimati Isotope (delta 13C, delta 18O, Sr/Ca) Data for 1938 to 1993

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What does this data set describe?

Title:
Kiritimati Isotope (delta 13C, delta 18O, Sr/Ca) Data for 1938 to 1993
Abstract:
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
  1. How should this data set be cited?

    Evans, Michael, Fairbanks, Richard G. , and Rubenstone, James L. , 199810, Kiritimati Isotope (delta 13C, delta 18O, Sr/Ca) Data for 1938 to 1993: World Data Center for Paleoclimatology Data Contribution Series 1998-035, World Data Center for Paleoclimatology, Boulder, Boulder.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -157.3
    East_Bounding_Coordinate: -157.3
    North_Bounding_Coordinate: 2.0
    South_Bounding_Coordinate: 2.0

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 1938
    Ending_Date: 1993
    Currentness_Reference: Publication Date

  5. What is the general form of this data set?

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

    2. What coordinate system is used to represent geographic features?

  7. How does the data set describe geographic features?

    coral variable
    coral variable (Source: coral variable)

    del13C
    delta 13C (per mil) (Source: 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.)

    Range of values
    Minimum:unknown
    Maximum:unknown
    Units:per mil
    Resolution:0.01

    del18O
    delta 18O (per mil) relative to PDB (Source: Craig, H., 1957. Isotopic standards for mass spectrometric analysis of carbon dioxide. Geochimica Cosmochimica Acta, 12:113-140)

    Range of values
    Minimum:unknown
    Maximum:unknown
    Units:per mil
    Resolution:0.01

    d18OAnom
    delta 18O (per mil) anomaly relative to the 1981-1986 mean (Source: Evans, M.N., R.G. Fairbanks and J.L. Rubenstone, A Proxy Index of ENSO Teleconnections, Nature 394:732-733, 1998.)

    Range of values
    Minimum:unknown
    Maximum:unknown
    Units:per mil
    Resolution:.01

    SrCa
    Sr/Ca Ratio (Source: 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.)

    Range of values
    Minimum:unknown
    Maximum:unknown
    Units:mmol/mol
    Resolution:0.015

    SrCaAnom
    Sr/Ca Ratio anomaly relative to the 1981-1986 mean (Source: Evans, M.N., R.G. Fairbanks and J.L. Rubenstone, A Proxy Index of ENSO Teleconnections, Nature 394:732-733, 1998.)

    Range of values
    Minimum:unknown
    Maximum:unknown
    Units:mmol/mol
    Resolution:0.015


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    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/>

  3. To whom should users address questions about the data?


Why was the data set created?

Paleoclimatic Research


How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

  3. What similar or related data should the user be aware of?


How reliable are the data; what problems remain in the data set?


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints: Please cite original reference when using this data

  1. Who distributes the data set? (Distributor 1 of 1)

    NOAA Paleoclimatology Program
    Data Manager
    325 Broadway, Code E/CC23
    Boulder, Colorado 80305-3328
    U.S.A.

    (303) 497-6280 (voice)
    (303) 497-6513 (FAX)
    paleo@noaa.gov

    Hours_of_Service: 9-5 MST Monday-Friday
  2. What's the catalog number I need to order this data set?

    Other Documents

  3. What legal disclaimers am I supposed to read?

    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

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 01-Apr-2011
Last Reviewed: 01-Apr-2011
Metadata author:
NOAA Paleoclimatology Program
Data Manager
325 Broadway, Code E/CC23
Boulder, Colorado 80305-3328
U.S.A.

(303) 497-6280 (voice)
(303) 497-6513 (FAX)
paleo@noaa.gov

Hours_of_Service: 9-5 MST Monday-Friday
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)


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