Next-generation radiocarbon calibration: Incorporating information on calibration curve covariance

下一代放射性碳校准：纳入校准曲线协方差信息

• 批准号: NE/X009815/1
• 负责人: Timothy John Heaton
• 金额: $ 10.13万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX009815%2F1
• 关键词: Next; generation; radiocarbon; calibration; Incorporating

A 6-month project to investigate the effect on radiocarbon calibration of covariance information within the IntCal20 radiocarbon calibration curve. Radiocarbon (14C) provides the most common method for dating the last 55,000 years and underpins the breadth of the environmental and archaeological sciences. Due to fluctuations in past levels of 14C, radiocarbon dating requires calibration against the internationally-agreed IntCal calibration curves. Traditionally, these IntCal calibration curves provide pointwise estimates of past 14C levels that are treated as independent from one year to the next. This independence suggests the true 14C level could change from the bottom of the uncertainty envelope in one year, to the top of the interval in the next, and then back to the bottom again. This extreme variability is unrealistic. In reality, the curve estimate has covariance - we expect it to vary more slowly over time within its uncertainty envelope. When calibrating multiple 14C determinations, essential for much environmental modelling, this covariance matters. The novel approach to curve construction implemented for the recent IntCal20 curves enabled storage of individual calibration curve realisations (which were summarised for the published pointwise IntCal20 estimates). Each realisation represents an entire plausible 14C history from 55,000 - 0 cal yr BP and encodes the curve covariance. This project aims to explore the effect of using these realisations (and hence covariance information) rather than pointwise calibration. Our findings have the potential to rewrite the way we calibrate.

一个为期6个月的研究IntCal20放射性碳校准曲线内协方差信息对放射性碳校准的影响的项目。放射性碳（14C）为测定过去55000年的年代提供了最常用的方法，并巩固了环境和考古科学的广度。由于过去14C水平的波动，放射性碳测年需要根据国际公认的IntCal校准曲线进行校准。传统上，这些IntCal校准曲线提供了过去14C水平的逐点估计，这些估计被视为独立于一年到下一年。这种独立性表明，真正的14C水平可能会在某一年从不确定范围的底部变化到下一年的顶部，然后再次回到底部。这种极端的可变性是不现实的。实际上，曲线估计具有协方差——我们期望它在其不确定性范围内随时间的变化更慢。当校准多个14C测定时，对于许多环境建模至关重要，这种协方差很重要。为最近的IntCal20曲线实现的新曲线构建方法可以存储单个校准曲线实现（为已发布的IntCal20点估计进行了总结）。每个实现代表了从55,000 - 0 calyr BP的整个可信的14C历史，并编码曲线协方差。该项目旨在探索使用这些实现（因此协方差信息）而不是逐点校准的效果。我们的发现有可能改写我们的校准方式。

项目成果

MARINE RADIOCARBON CALIBRATION IN POLAR REGIONS: A SIMPLE APPROXIMATE APPROACH USING MARINE20

• DOI: 10.1017/rdc.2023.42
• 发表时间: 2023-08
• 期刊: Radiocarbon
• 影响因子: 8.3
• 作者: T. Heaton;M. Butzin;E. Bard;C. Bronk Ramsey;K. Hughen;P. Köhler;P. Reimer

Atmospheric radiocarbon levels were highly variable during the last deglaciation

• DOI: 10.1038/s43247-023-00929-9
• 发表时间: 2023-07
• 期刊: Communications Earth & Environment
• 作者: S. Talamo;M. Friedrich;F. Adolphi;B. Kromer;T. Heaton;Silvia Cercatillo;R. Muscheler;Dragana Paleček;Enrico Pelloni;Laura Tassoni;V. Toniello;L. Wacker