Recent Developments in Calibration for Archaeological and Environmental Samples
Open accessAbstract
The curves recommended for calibrating radiocarbon (14 C) dates into absolute dates have been updated. For calibrating atmospheric samples from the Northern Hemisphere, the new curve is called IntCal20. This is accompanied by associated curves SHCal20 for the Southern Hemisphere, and Marine20 for marine samples. In this “companion article” we discuss advances and developments that have led to improvements in the updated curves and highlight some issues of relevance for the general readership. In particular the dendrochronological based part of the curve has seen a significant increase in data, with single-year resolution for certain time ranges, extending back to 13,910 calBP. Beyond the tree rings, the new curve is based upon an updated combination of marine corals, speleothems, macrofossils, and varved sediments and now reaches back to 55,000 calBP. Alongside these data advances, we have developed a new, bespoke statistical curve construction methodology to allow better incorporation of the diverse constituent records and produce a more robust curve with uncertainties. Combined, these data and methodological advances offer the potential for significant new insight into our past. We discuss some implications for the user, such as the dating of the Santorini eruption and also some consequences of the new curve for Paleolithic archaeology.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The impact of these 14C offsets can be substantial for Mediterranean and Near Eastern archaeology because of intricate and densely integrated timeframes and small margins of tolerance.
“While small, the impact of these 14C offsets can be substantial for Mediterranean and Near Eastern archaeology because of the intricate and densely integrated timeframes involved and the small margins of tolerance2,7,8,10,12.”
From Radiocarbon offsets and old world chronology as relevant to Mesopotamia, Egypt, Anatolia and Thera (Santorini) (2020) · cites this paper as [2]
The Regional and Seasonal Effects section (p. 1110) says small systematic ¹⁴C offsets matter when complex models seek decadal precision, particularly across large datasets. The Conclusions call a roughly 20-year calibration shift crucial to dating the Santorini eruption. These passages support the potential for substantial archaeological impact, but do not establish the claim’s broader scope across Mediterranean and Near Eastern archaeology or its stated explanation of densely integrated timeframes. (LLM, conf=0.82)
Experimental — accuracy not yet measuredThe circumstances of fluctuating offsets complicate the hypothesis of a single Northern Hemisphere calibration curve, with any variation assumed as effectively comparable with or incorporated within error terms.
“These circumstances complicate the elegant hypothesis of a single NH calibration curve, with any variation assumed as effectively comparable with (or incorporated within) error terms2.”
From Radiocarbon offsets and old world chronology as relevant to Mesopotamia, Egypt, Anatolia and Thera (Santorini) (2020) · cites this paper as [2]
The ‘Regional and Seasonal Effects’ section (p. 1110) describes offsets from the hemispherical average and says most regional or seasonal effects are likely comparable to measurement precision. ‘Construction of the IntCal20 Curve’ explains that additional variation relative to a single hemispheric curve is incorporated into predictive intervals. The claim overgeneralizes this to any variation: the paper excepts major carbon-reservoir effects and cautions that offsets may be correlated across a dataset rather than captured by laboratory error terms. (LLM, conf=0.82)
Experimental — accuracy not yet measuredAnalysis with IntCal20 using (1) weighted average 14C ages, (2) a published dataset and alternative appropriate method, or (3) the series of 14C dates on an olive branch found buried by the Santorini/Thera eruption, all indicate a most likely late seventeenth century BCE date, but include varying probability in the earlier-mid sixteenth century BCE.
“Analysis with IntCal20 using (1) weighted average 14C ages2, (2) a published dataset and alternative appropriate method52,53, or (3) the series of 14C dates on an olive branch found buried by the Santorini/Thera eruption2,53,55, all indicate a most likely late seventeenth century BCE date, but include varying probability in the earlier-mid sixteenth century BCE (Supplementary Figs. S10a,b, S11a,b,”
From Radiocarbon offsets and old world chronology as relevant to Mesopotamia, Egypt, Anatolia and Thera (Santorini) (2020) · cites this paper as [2]
Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.
Experimental — accuracy not yet measuredWhen jointly calibrating multiple 14C samples affected by a systematic offset, it is necessary to model that shared offset explicitly during calibration.
“However, when jointly calibrating multiple 14C samples which are all affected by a systematic offset, for example in an ordered sequence or a wiggle match, it is necessary to model that shared offset explicitly during calibration13.”
From Olive shrub buried on Therasia supports a mid-16th century BCE date for the Thera eruption (2023) · cites this paper as [13]
The Regional and Seasonal Effects section (p. 1110) recommends explicitly allowing for a shared offset in complex Bayesian models and wiggle matches, and notes that offsets can be correlated across a dataset. It calls this approach “prudent,” however, rather than saying it is necessary in every joint calibration affected by an offset. (LLM, conf=0.85)
Experimental — accuracy not yet measuredCalibrated age distributions based on radiocarbon determinations of materials buried by eruption deposits place the Thera eruption around 1600 BCE.
“persistent differences between the calibrated age distributions based on radiocarbon (14C) determinations of materials buried by eruption deposits9–13, placing the eruption around 1600 BCE”
From Olive shrub buried on Therasia supports a mid-16th century BCE date for the Thera eruption (2023) · cites this paper as [13]
In “The Minoan Santorini (Thera) Eruption” (pp. 1102–1104), the paper reports radiocarbon dates from key sites and calibrated dates near 1600 BCE. But it does not identify those dated materials as buried by eruption deposits, and its IntCal20 analysis gives several possible age ranges, with the largest probability around 1625 BCE rather than a single date around 1600 BCE. (LLM, conf=0.84)
Experimental — accuracy not yet measured
IntCal20 employs a single 14C calibration curve as an approximation for different regions across the Northern Hemisphere mid-latitudes.
“The new IntCal20 radiocarbon record continues decades of successful practice by employing one calibration curve as an approximation for different regions across the hemisphere.”
From Radiocarbon offsets and old world chronology as relevant to Mesopotamia, Egypt, Anatolia and Thera (Santorini) (2020) · cites this paper as [2]
In several instances including this one, detailed new measurements of time intervals with AMS 14C have indicated slightly older 14C ages.
“As noted, in several instances including this one, detailed new measurements of time intervals with AMS 14C have indicated slightly older 14C ages1,2,10,38,39,43–48.”
From Radiocarbon offsets and old world chronology as relevant to Mesopotamia, Egypt, Anatolia and Thera (Santorini) (2020) · cites this paper as [2]
The IntCal20 calibration curve includes several hundred recent 14C measurements on known-age tree-rings for the calendar interval 1700-1500 BCE, making this two-century interval by far the best-defined portion of the IntCal20 14C calibration curve in the BCE era.
“The IntCal20 calibration curve includes several hundred recent 14 C measurements on known-age tree-rings for the calendar interval 1700-1500 BCE, due to the widespread recent interest in trying to define this period and the Thera eruption date (since [12]), making this two-century interval by far the best-defined portion of the IntCal20 14 C calibration curve in the BCE era [41,43] (Fig 1).”
From Second Intermediate Period date for the Thera (Santorini) eruption and historical implications (2022) · cites this paper as [43]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
Reimer, P. J., Austin, W. E. N., Bard, E., Bayliss, A., Blackwell, P. G., Bronk Ramsey, C., Butzin, M., Cheng, H., Edwards, R. L., Friedrich, M., et al. (2020) · Radiocarbon · doi:10.1017/rdc.2020.41 · Cited by 7,900 · see citing works
Self-citation<sup>14</sup> C Activity and Global Carbon Cycle Changes over the Past 50,000 Years
Hughen, K., Lehman, S., Southon, J., Overpeck, J., Marchal, O., Herring, C., & Turnbull, J. (2004) · Science · doi:10.1126/science.1090300 · Cited by 492 · see citing works
Santorini Eruption Radiocarbon Dated to 1627-1600 B.C.
Friedrich, W. L., Kromer, B., Friedrich, M., Heinemeier, J., Pfeiffer, T., & Talamo, S. (2006) · Science · doi:10.1126/science.1125087 · Cited by 377 · see citing works
Self-citationSeasonal variation of mass transport across the tropopause
Appenzeller, C., Holton, J. R., & Rosenlof, K. H. (1996) · Journal of Geophysical Research: Atmospheres · doi:10.1029/96jd00821 · Cited by 352 · see citing works
Radiocarbon-Based Chronology for Dynastic Egypt
Ramsey, C. B., Dee, M. W., Rowland, J. M., Higham, T. F. G., Harris, S. A., Brock, F., Quiles, A., Wild, E. M., Marcus, E. S., & Shortland, A. J. (2010) · Science · doi:10.1126/science.1189395 · Cited by 246 · see citing works
Self-citationBruins, H. J., MacGillivray, J. A., Synolakis, C. E., Benjamini, C., Keller, J., Kisch, H. J., Klügel, A., & van der Plicht, J. (2008) · Journal of Archaeological Science · doi:10.1016/j.jas.2007.08.017 · Cited by 193 · see citing works
A high-resolution record of atmospheric 14C based on Hulu Cave speleothem H82
Southon, J., Noronha, A. L., Cheng, H., Edwards, R. L., & Wang, Y. (2012) · Quaternary Science Reviews · doi:10.1016/j.quascirev.2011.11.022 · Cited by 175 · see citing works
Atmospheric <sup>14</sup> C/ <sup>12</sup> C changes during the last glacial period from Hulu Cave
Cheng, H., Edwards, R. L., Southon, J., Matsumoto, K., Feinberg, J. M., Sinha, A., Zhou, W., Li, H., Li, X., Xu, Y., et al. (2018) · Science · doi:10.1126/science.aau0747 · Cited by 135 · see citing works
Annual radiocarbon record indicates 16th century BCE date for the Thera eruption
Pearson, C. L., Brewer, P. W., Brown, D., Heaton, T. J., Hodgins, G. W. L., Jull, A. J. T., Lange, T., & Salzer, M. W. (2018) · Science Advances · doi:10.1126/sciadv.aar8241 · Cited by 120 · see citing works
Self-citationA short note on marine reservoir age simulations used in IntCal20
Butzin, M., Heaton, T. J., Köhler, P., & Lohmann, G. (2020) · Radiocarbon · doi:10.1017/rdc.2020.9 · Cited by 67 · see citing works
Self-citationKutschera, W., Bietak, M., Wild, E. M., Ramsey, C. B., Dee, M., Golser, R., Kopetzky, K., Stadler, P., Steier, P., Thanheiser, U., et al. (2012) · Radiocarbon · doi:10.1017/s0033822200047172 · Cited by 58 · see citing works
Self-citationKaiser, K. F., Friedrich, M., Miramont, C., Kromer, B., Sgier, M., Schaub, M., Boeren, I., Remmele, S., Talamo, S., Guibal, F., et al. (2012) · Quaternary Science Reviews · doi:10.1016/j.quascirev.2010.07.009 · Cited by 56 · see citing works
Self-citationAnnual Variation in Atmospheric <sup>14</sup>C Between 1700 BC and 1480 BC
Pearson, C., Wacker, L., Bayliss, A., Brown, D., Salzer, M., Brewer, P., Bollhalder, S., Boswijk, G., & Hodgins, G. (2020) · Radiocarbon · doi:10.1017/rdc.2020.14 · Cited by 40 · see citing works
The Date of the Minoan Santorini Eruption: Quantifying the “Offset”
Höflmayer, F. (2012) · Radiocarbon · doi:10.1017/s0033822200047196 · Cited by 39 · cited 1× · see citing works
“This number (the 14C date) is confirmed by other analyses (Höflmayer 2012) and consistent with other records like tsunami deposits on Crete (Bruins et al. 2008).”
ResultDecadally resolved Lateglacial radiocarbon evidence from New Zealand kauri
Hogg, A., Southon, J., Turney, C., Palmer, J., Ramsey, C. B., Fenwick, P., Boswijk, G., Büntgen, U., Friedrich, M., Helle, G., et al. (2016) · Radiocarbon · doi:10.1017/rdc.2016.86 · Cited by 33 · see citing works
Self-citationMcAneney, J., & Baillie, M. (2019) · Antiquity · doi:10.15184/aqy.2018.165 · Cited by 33 · see citing works
Testing and Improving the IntCal20 Calibration Curve with Independent Records
Muscheler, R., Adolphi, F., Heaton, T. J., Bronk Ramsey, C., Svensson, A., van der Plicht, J., & Reimer, P. J. (2020) · Radiocarbon · doi:10.1017/rdc.2020.54 · Cited by 30 · see citing works
Self-citationA New Annual<sup>14</sup>C Dataset for Calibrating the Thera Eruption
Friedrich, R., Kromer, B., Wacker, L., Olsen, J., Remmele, S., Lindauer, S., Land, A., & Pearson, C. (2020) · Radiocarbon · doi:10.1017/rdc.2020.33 · Cited by 20 · see citing works
Ehrlich, Y., Regev, L., & Boaretto, E. (2018) · Scientific Reports · doi:10.1038/s41598-018-29392-9 · Cited by 19 · see citing works
Illuminating IntCal during the Younger Dryas
Reinig, F., Sookdeo, A., Esper, J., Friedrich, M., Guidobaldi, G., Helle, G., Kromer, B., Nievergelt, D., Pauly, M., Tegel, W., et al. (2020) · Radiocarbon · doi:10.1017/rdc.2020.15 · Cited by 18 · cited 1× · see citing works
“As put forward by Renfrew (1999), the first revolution was that samples could be dated by a scientific method at all; the second revolution was that calibration turned 14C dates into absolute (calendar) dates.”
Background
Flagged first, then by citations
Research works printed but not linked: 18
- Butzin M, Köhler P, Lohmann G. 2017. Marine radiocarbon reservoir age simulations for the past 50,000 years. Geophysical Research Letters 44:8473-8480.
- David F, Connet N, Girard M, Lhomme V, Miskovsky JC, Roblin-Jouve A. 2001. Le Châtelperronien de la grotte du Renne à Arcy- sur-Cure (Yonne). Données sédimentologiques et chronostratigraphiques. Bulletin de la Société Préhistoire Francaise 98:207-230.
- Fu Q, Li H, Moorjani P, Jay F, Slepchenko SM, Bondarev AA, Johnson PLF, Aximu-Petri A, 1114 J van der Plicht et al. https://doi.org/10.1017/RDC.2020.22 Published online by Cambridge University Press
- Hoffman DL, Beck JW, Richards DA, Smart PL, Singarayer JS, Ketchmak T, Hawkesworth CJ. 2010. Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas. Earth and Planetary Science Letters 289:1-10.
- Hublin JJ, Talamo S, Julien M, David F, Connet N, Bodu P, Vandermeersch B, Richards MP. 2012. Radiocarbon dates from the Grotte du Renne and Saint-Césaire support a Neandertal origin for the Châtelperronian. Proceedings of the National Academy of Sciences 109:18743-18748.
- Köhler P, Fischer H, Munhoven G, Zeebe RE. 2005. Quantitative interpretation of atmospheric carbon records over the last glacial termination. Global Biogeochem. Cycles 19, GB4020. doi: 10.1029/2004GB002345. · DOI
- Köhler P, Muscheler R, Fischer H. 2006. A model- based interpretation of low-frequency changes in the carbon cycle during the last 120,000 years and its implications for the reconstruction of atmospheric Δ 14 C. Geochem. Geophys. Geosyst. 7, Q11N06. doi: 10.1029/2005GC001228. · DOI
- Köhler P, Fischer H. 2004. Simulating changes in the terrestrial biosphere during the last glacial/ interglacial transition. Global Planetary Change 43: 33-55. doi: 10.1016/j.gloplacha.2004.02.005. · DOI
- Köhler P, Fischer H. 2006. Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years. Climate of the Past 2:57-78. doi: 10.5194/cp-2-57-2006. · DOI
- Kromer B, Ambers J, Baillie MGL, Damon PE, Hesshaimer V, Hofmann J, Jöris O, Levin I, Manning SW, McCormac FG, et al. 1996. Report: Summary of the workshop "Aspects of high-precision radiocarbon calibration". Radiocarbon 38:607-610.
- Manning S. 2014. A test of time and a test of time revisited: The volcano of Thera and the chronology and history of the Aegean and East IntCal20 Companion: Archaeological & Environmental Samples 1115 https://doi.org/10.1017/RDC.2020.22 Published online by Cambridge University Press Mediterranean in the mid-second millennium BC. Oxford/Philadelphia: Oxbow. 494 p. ISBN 9781782972198.
- Miyake F, Masuda K, Nakamura T. 2013. Another rapid event in the carbon-14 content of tree rings. Nature Communications 4. doi: 10.1038/ ncomms2783. · DOI
- Pearson GW, Stuiver M. 1986. High-precision cali- bration of the radiocarbon timescale 500-2500 BC. Radiocarbon 28:839-862.
- Stohl A, Bonasoni P, Cristofanelli P, Collins W, Feichter J, Frank A, Forster C, Gerasopoulos E, Gäggeler H, James P, et al. 2003. Stratosphere- troposphere exchange: A review, and what we have learned from STACCATO. Journal of Geophysical Research Atmospheres 108(D12). doi: 10.1029/2002/JD002490. · DOI
- Stuiver M, Pearson GW. 1986. High-precision calibration of the radiocarbon timescale AD 1950-500 BC. Radiocarbon 28:805-838.
- Trinkaus E, Moldovan O, Milota S, Bîlgar A, Sarcina L, Athreya S, Bailey SE, Rodrigo R, Mircea G, Higham T, et al. 2003. An early modern human from the Pestera cu Oase, Romania. Proceedings of the National Academy of Sciences 100:11231-11236.
- Welker F, Hajdinjak M, Talamo S, Jaouen K, Dannemann M, David F, Julien M, Meyer M, Kelso J, Barnes I, et al. 2016. Palaeoproteomic evidence identifies archaic hominins associated with the Châtelperronian at the Grotte du Renne. Proceedings of the National Academy of Sciences 113:11162-11167.
- Weninger B, Jöris O. 2004. Glacial radiocarbon age calibration: The CalPal program. In: Higham T, Bronk Ramsey C, Owen C, editors. Radiocarbon and Archaeology, Volume Monograph 62. Oxford: St Catherine's College, Oxford University School of Archaeology. p. 9-15. IntCal20 Companion: Archaeological & Environmental Samples 1117 https://doi.org/10.1017/RDC.2020.22 Published online by Cambridge University Press
Cited by
Sorted by citations
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
Reimer, P. J., Austin, W. E. N., Bard, E., Bayliss, A., Blackwell, P. G., Bronk Ramsey, C., Butzin, M., Cheng, H., Edwards, R. L., Friedrich, M., et al. (2020) · Radiocarbon · doi:10.1017/rdc.2020.41 · Cited by 7,900 · see citing works
Self-citationHeaton, T. J., Blaauw, M., Blackwell, P. G., Bronk Ramsey, C., Reimer, P. J., & Scott, E. M. (2020) · Radiocarbon · doi:10.1017/rdc.2020.46 · Cited by 124 · see citing works
Self-citationManning, S. W., Wacker, L., Büntgen, U., Bronk Ramsey, C., Dee, M. W., Kromer, B., Lorentzen, B., & Tegel, W. (2020) · Scientific Reports · doi:10.1038/s41598-020-69287-2 · Cited by 35 · see citing works
“Analysis with IntCal20 using (1) weighted average 14C ages2, (2) a published dataset and alternative appropriate method52,53, or (3) the series of 14C dates on an olive branch found buried by the Santorini/Thera eruption2,53,55, all indicate a most likely late seventeenth century BCE date, but include varying probabil…”
BackgroundMethodResultInfluentialSecond Intermediate Period date for the Thera (Santorini) eruption and historical implications
Manning, S. W. (2022) · PLOS ONE · doi:10.1371/journal.pone.0274835 · Cited by 13 · see citing works
Olive shrub buried on Therasia supports a mid-16th century BCE date for the Thera eruption
Pearson, C., Sbonias, K., Tzachili, I., & Heaton, T. J. (2023) · Scientific Reports · doi:10.1038/s41598-023-33696-w · Cited by 13 · see citing works
Self-citationManning, S. W. (2024) · Radiocarbon · doi:10.1017/rdc.2024.44 · Cited by 9 · see citing works
“…ca. 1628 BC — made before revision/improvement of the radiocarbon calibration curve 1700 – 1500 BC (e.g. Pearson et al. 2020; Reimer et al. 2020; van der Plicht et al. 2020) with this 1628 BC volcanic signal subsequently identified as associated with Aniakchak II (V2 in Pearson et al. 2022) — a…”
BackgroundBruins, H. J., & van der Plicht, J. (2025) · PLOS One · doi:10.1371/journal.pone.0330702 · Cited by 1 · see citing works
“Since IntCal98 [56], hundreds of additional dendrochrono-logical 14 C dates have been measured with high precision [58], which have become incorporated in the present IntCal20 calibration curve [59], available since 2020.”
- Authors
- van der Plicht, J., Bronk Ramsey, C., Heaton, T. J., Scott, E. M., & Talamo, S.
- Affiliations
- University of Sheffield (GB)
- University of Glasgow (GB)
- University of Bologna (IT)
- Venue
- Radiocarbon
- Publisher
- Cambridge University Press (CUP)
- Published
- 2020-04-21
- Volume
- 62
- Issue
- 4
- Pages
- 1095-1117
- ISSN
- 0033-8222 (ISSN-L)
- 1945-5755
- OpenAlex
- W3020226260
- Cited by
- 62
- References
- 20
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 7 · 2023: 18 · 2022: 14 · 2021: 9 · 2020: 10
- FWCI
- 7.29
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Locations
- Radiocarbon (publishedVersion, cc-by)
- University of Groningen research database (University of Groningen / Centre for Information Technology) (publishedVersion, cc-by)
- ENLIGHTEN (Jurnal Bimbingan dan Konseling Islam) (acceptedVersion, cc-by-sa)
- White Rose Research Online (University of Leeds, The University of Sheffield, University of York) (acceptedVersion)
- Archivio istituzionale della ricerca (Alma Mater Studiorum Università di Bologna) (submittedVersion, cc-by)
- University of Groningen research database (University of Groningen / Centre for Information Technology) (submittedVersion, cc-by)
- Funders
- Leverhulme Trust (RF-2019-140\9)
- University of Cambridge
- European Commission (2020 ‘, HORIZON2020)
- Natural Environment Research Council (NE/H007865/1, NRCF010002)
- H2020 European Research Council (803147)
- Topics
- Physical Sciences › Earth and Planetary Sciences › Paleontology › Archaeology and ancient environmental studies
- Physical Sciences › Earth and Planetary Sciences › Atmospheric Science › Geology and Paleoclimatology Research
- Physical Sciences › Earth and Planetary Sciences › Atmospheric Science › Tree-ring climate responses
- Keywords
- radiocarbon calibration, IntCal20, calibration curve, dendrochronology, marine corals, speleothems, macrofossils, varved sediments, calibration uncertainty, Santorini eruption, Palaeolithic archaeology, environmental samples
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
