The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0-55 cal kBP)

Research output: Contribution to journalArticle

Abstract

Radiocarbon (C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.

Details

Authors
  • Paula J. Reimer
  • William E.N. Austin
  • Edouard Bard
  • Alex Bayliss
  • Paul G. Blackwell
  • Christopher Bronk Ramsey
  • Martin Butzin
  • Hai Cheng
  • R. Lawrence Edwards
  • Michael Friedrich
  • Pieter M. Grootes
  • Thomas P. Guilderson
  • Irka Hajdas
  • Timothy J. Heaton
  • Alan G. Hogg
  • Konrad A. Hughen
  • Bernd Kromer
  • Sturt W. Manning
  • Jonathan G. Palmer
  • Charlotte Pearson
  • Johannes Van Der Plicht
  • Ron W. Reimer
  • David A. Richards
  • E. Marian Scott
  • John R. Southon
  • Christian S.M. Turney
  • Lukas Wacker
  • Ulf Büntgen
  • Manuela Capano
  • Simon M. Fahrni
  • Ronny Friedrich
  • Peter Köhler
  • Sabrina Kudsk
  • Fusa Miyake
  • Jesper Olsen
  • Frederick Reinig
  • Minoru Sakamoto
  • Adam Sookdeo
  • Sahra Talamo
Organisations
External organisations
  • Queen's University Belfast
  • University of St Andrews
  • Scottish Association for Marine Science
  • Aix-Marseille University
  • University of Sheffield
  • University of Oxford
  • Alfred-Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven
  • Xi'an Jiaotong University
  • University of Minnesota
  • Nanjing Normal University
  • University of Hohenheim
  • University of Kiel
  • Lawrence Livermore National Laboratory
  • University of California, Santa Cruz
  • ETH Zürich
  • University of Waikato
  • Woods Hole Oceanographic Institution
  • Heidelberg University
  • Cornell University
  • University of New South Wales
  • University of Arizona
  • University of Groningen
  • University of Bristol
  • University of Glasgow
  • University of California, Irvine
  • University of Bern
  • University of Cambridge
  • Swiss Federal Institute for Forest, Snow and Landscape Research
  • Masaryk University
  • Aarhus University
  • Nagoya University
  • St. Orsola-Malpighi University Hospital
  • Curt-Engelhorn Center for Archaeometry gGmbH
  • National Museum of Japanese History
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Geology

Keywords

  • calibration curve, IntCal20, radiocarbon
Original languageEnglish
Pages (from-to)725-757
Number of pages33
JournalRadiocarbon
Volume62
Issue number4
Publication statusPublished - 2020
Publication categoryResearch
Peer-reviewedYes