Urvina Bay, Galapagos Coral Radiocarbon (delta 14C) Data for 1956 to 1982

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Frequently anticipated questions:


What does this data set describe?

Title:
Urvina Bay, Galapagos Coral Radiocarbon (delta 14C) Data for 1956 to 1982
Abstract:
Urvina Bay coral radiocarbon (14C) timeseries. (90 deg W, 0.5 deg S) Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per mil as documented by an in-house homogenized coral standard, and presented as AGE CORRECTED DELTA-14C [see Stuiver Polach, 1977]. The sample cores were made on a Porites lobata coral, in Urvina Bay, Isabella Island, Galapagos Archipelago by G. Wellington, and supplied by R. Dunbar. Cores were split and cleaned with distilled water. After identifying the major vertical growth axis, the coral was sequentially sampled at 2 mm increments with a low-speed drill. Splits (~1 mg) were reacted in vacuo in a modified autocarbonate device at 90 deg C and the purified CO2 analyzed on a gas source stable isotope ratio mass spectrometer. The remaining sample splits (~7-8 mg) were placed in individual reaction chambers, evacuated, heated, and then acidified with orthophosphoric acid at 90 deg C. The evolved CO2 was purified, trapped, and converted to graphite in the presence of cobalt catalyst in individual reactors [Vogel et al., 1987]. Graphite targets were measured at the Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory [Davis et al., 1990]. Radiocarbon results are reported as Delta-14C (") as defined by Stuiver and Polach [1977] and include the d13C correction obtained from the stable isotope results. Analytical precision and accuracy of the radiocarbon measurements is +/- 4" (1s) based on repeated analyses of an in-house homogenized near-modern coral and accepted secondary and tertiary radiocarbon standards. The coral died during the 1982/83 El Nino event. In keeping with the definition of "high-precision radiocarbon" ( less than 3 per mil, 1-sigma) data have been rounded to zero significant figures. The age model for these data was derived from a preliminary delta-13C age model which was then optimized by mapping the delta-18O data to a local instrumental SST record. A similar result was obtained using high-precision [Sr/Ca] analyses on aliquots of the same drilled powders used for d18O,d13C, and Delta-14C. Age model errors are estimated (brute force approach) at +/- 1 month.
  1. How should this data set be cited?

    Guilderson, T., and Schrag, D., 199909, Urvina Bay, Galapagos Coral Radiocarbon (delta 14C) Data for 1956 to 1982: World Data Center for Paleoclimatology Data Contribution Series 1999-051, World Data Center for Paleoclimatology, Boulder, Boulder.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -90
    East_Bounding_Coordinate: -90
    North_Bounding_Coordinate: -0.5
    South_Bounding_Coordinate: -0.5

  3. What does it look like?

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

    Beginning_Date: 1956
    Ending_Date: 1982
    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)

    del14C
    delta 14C (per mil) (Source: Druffel, E. M., 1981, Radiocarbon in annual coral rings from the eastern tropical Pacific Ocean: Geophysical Research Letters, v. 8, p. 59-62.)

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


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?

    Guilderson, T.P., and D.P. Schrag, Abrupt shift in subsurface temperatures in the Eastern Tropical Pacific associated with recent changes in El Nino, Science, 281, 240-243 1998.

  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 errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 31-Mar-2011
Last Reviewed: 31-Mar-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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