Open Access
September 2011 Flexible paleoclimate age-depth models using an autoregressive gamma process
Maarten Blaauw, J. Andrés Christen
Bayesian Anal. 6(3): 457-474 (September 2011). DOI: 10.1214/11-BA618


Radiocarbon dating is routinely used in paleoecology to build chronologies of lake and peat sediments, aiming at inferring a model that would relate the sediment depth with its age. We present a new approach for chronology building (called "Bacon") that has received enthusiastic attention by paleoecologists. Our methodology is based on controlling core accumulation rates using a gamma autoregressive semiparametric model with an arbitrary number of subdivisions along the sediment. Using prior knowledge about accumulation rates is crucial and informative priors are routinely used. Since many sediment cores are currently analyzed, using different data sets and prior distributions, a robust (adaptive) MCMC is very useful. We use the t-walk (Christen and Fox, 2010), a self adjusting, robust MCMC sampling algorithm, that works acceptably well in many situations. Outliers are also addressed using a recent approach that considers a Student-t model for radiocarbon data. Two examples are presented here, that of a peat core and a core from a lake, and our results are compared with other approaches.


Download Citation

Maarten Blaauw. J. Andrés Christen. "Flexible paleoclimate age-depth models using an autoregressive gamma process." Bayesian Anal. 6 (3) 457 - 474, September 2011.


Published: September 2011
First available in Project Euclid: 13 June 2012

zbMATH: 1330.62413
MathSciNet: MR2843540
Digital Object Identifier: 10.1214/11-BA618

Primary: 60K40
Secondary: 62F15 , 62M10 , 62P12 , 86A60

Keywords: Age-Depth models , AR Gamma process , Paleoecology , Radiocarbon

Rights: Copyright © 2011 International Society for Bayesian Analysis

Vol.6 • No. 3 • September 2011
Back to Top