IntCal09 and Marine09 calibration curves
IntCal09 Northern Hemisphere atmospheric radiocarbon calibration curve
Format: cal BP, 14C BP, ± Error, Δ14C (‰), σ14C
Δ is age-corrected as per Stuiver and Polach (1977). The model used for curve construction is presented in Heaton et al. (2009). Note that the data spacing changes from 5 years for the range from 0 to 11.2 to cal kBP, 10 yrs for 11.2–15 cal kBP, 20 yrs for 15–25 cal kBP, 50 yrs for 25–40 cal kBP, and 100 yrs for 40–50 cal kBP.
Marine radiocarbon calibration curve
Format: cal BP, 14C BP, ± Error, Δ14C (‰), σ14C
Δ is age-corrected as per Stuiver and Polach (1977). The model used for curve construction is presented in Heaton et al. (2009). The marine radiocarbon curve for the period of 0–12.5 cal kBP is taken from the Marine04 curve, which is calculated with the ocean-atmosphere box diffusion model (Oeschger et al. 1975; Stuiver and Braziunas 1993) as described in Hughen et al. (2004). The output of the box model is given in the file marmod09.csv and is decribed below. Note that the data spacing changes from 5 years for the range from 0 to 12.5 to cal kBP, 10 yrs for 11.2–15 cal kBP, 20 yrs for 15–25 cal kBP, 50 yrs for 25–40 cal kBP, and 100 yrs for 40–50 cal kBP
IntCal09 and Marine09 raw data sets
Files: IntCal09_atm_rawdata.csv (atmospheric data sets)
IntCal09_mar_rawdata.csv (marine data sets)
File format: Starting cal age BP, 14C age BP, total 14C error, cal year span, cal year uncertainty, wiggle-match error, varve Count Error, age model error, Lab ID, data set number, observation number, location or other info
The data used for IntCal09 and Marine09 construction is given in the files IntCal09_atm_rawdata.csv and IntCal09_mar_rawdata.csv. A summary of the data sets is given below with references to the original data sets. These are catalogued by the institute where the 14C measurements were made in some cases and in others by the first author on the publications. The data sets are also discussed in more detail in Reimer et al. (2009). The model used for data set construction is presented in Heaton et al. (2009).
Rather than giving midpoints, the cal ages are given as a starting year with a cal yr span. The cal year span is equivalent to the number of tree rings, coral rings or varves in a sample. The cal year span is an estimate for some of the coral data sets. The 14C age BP is the conventional radiocarbon age as defined by Stuiver and Polach (1977) and has been reservoir-corrected for marine samples as discussed in Reimer et al. (2009). The total 14C error is the standard measurement error multiplied by a lab error multiplier (between 1.0 and 2.0) with the uncertainty in the reservoir correction added in quadrature for marine samples. Lab IDs are given when provided by the investigators. Wiggle-match error and varve count error apply to the Cariaco Basin varved sediment record only. Age model error is given separately for the Cariaco Basin non-varved sediment record but included in the cal year uncertainty for the Iberian Margin data set. Data set numbers have no relationship to publication date but were assigned somewhat randomly in the database with tree-ring data sets numbering from 1–7 and marine data sets from 10–15, 20 and 21. Observation number is simply a count of the number of observations in a particular data set.
Data sets are described and fully referenced in the Appendix of Reimer et al. (2009). Lab codes for 14C measurements are given in parentheses.
Data set 1: University of Washington (QL) tree ring
Data set 2: Queen's University Belfast (UB) tree ring
Data set 3: University of Waikato (Wk) tree ring
Data set 4: University of Groningen (GrN) tree ring
Data set 5: Heidelberger Akademie der Wissenschaften (Hd) tree ring
Data set 6: CSIR, Pretoria (Pta) tree ring
Data set 7: Center for Accelerator Mass Spectrometry, LLNL (CAMS) tree ring
Data set 8-9: numbers not currently in use
Data set 10: E. Bard et al. (GifA) corals
Data set 11: R.G. Fairbanks et al. (CAMS, Gif and KIA) corals
Data set 12: R. L. Edwards et al. (AA, WHOI) corals
Data set 13: G.S. Burr et al. (AA) corals
Data set 14: K. B. Cutler et al. (AA) corals
Data set 15: Hughen et al. (CAMS) foraminifera
Data set 16: Marine box model
Data set 17-19: numbers not currently in use
Data set 20: Hughen et al. (CAMS, NSRL, and UCIAMS) foraminifera
Data set 21: E. Bard et al. (KIA, GifA, OS) foraminifera
Ocean-atmosphere box model output
Format: cal BP, atmospheric Δ14C (‰), 14C production rate (atoms/cm2/sec), mixed layer Δ14C (‰), thermocline Δ14C (‰), deep ocean Δ14C (‰)
Heaton TJ, Blackwell PG, Buck CE. 2009. A Bayesian approach to the estimation of radiocarbon calibration curves: the IntCal09 methodology. Radiocarbon 51(4):1151–64.
Oeschger H, Siegenthaler U, Schotterer U, Gugelmann A. 1975. A box diffusion model to study the carbon dioxide exhange in nature. Tellus 27:168–92.
Reimer PJ, Baillie MGL, Bard E, Bayliss A, Beck JW, Blackwell PG, Bronk Ramsey C, Buck CE, Burr GS, Edwards RL, Friedrich M, Grootes PM, Guilderson TP, Hajdas I, Heaton TJ, Hogg AG, Hughen KA, Kaiser KF, Kromer B, McCormac FG, Manning SW, Reimer RW, Richards DA, Southon JR, Talamo S, Turney CSM, van der Plicht J, Weyhenmeyer CE. 2009. IntCal09 and Marine09 radiocarbon age calibration curves, 0–50,000 years cal BP. Radiocarbon 51(4):1111–50.
Stuiver M, Braziunas TF. 1993. Modeling atmospheric 14C influences and 14C ages of marine samples to 10,000 BC. Radiocarbon 35(1):137–89.