Towards a Decadally-Resolved Radiocarbon Calibration for the Last Glacial Period (30,000-11,700 years ago) Using New Zealand Kauri (Agathis australis)

使用新西兰贝壳杉 (Agathis australis) 实现末次冰期（30,000-11,700 年前）的十年分辨率放射性碳校准

• 批准号: NE/H007865/1
• 负责人: Christopher Ramsey
• 金额: $ 14.51万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH007865%2F1
• 关键词: Towards; Decadally; Resolved; Radiocarbon; Calibration

Past climate change provides a critical baseline against which to compare present and future warming. Unfortunately, however, although numerous reconstructions spanning the last ice age have been made, most of the records cannot be precisely correlated to one another. The main problem is the vast majority of records have been radiocarbon dated for which no internationally-accepted calibration curve exists, precluding the placement of reconstructions on a calendar timescale and preventing robust comparisons with high-resolution and absolutely dated sequences (such as ice cores). This is a significant problem for the scientific community. 'Calibration' of radiocarbon-dated records can result in the conclusion that climate change led, lagged or was synchronous around the world depending on which conversion is used, preventing the scientific community from gaining a detailed understanding of mechanisms of change in the Earth system. An accurate and precise radiocarbon calibration curve should be based on an absolutely dated record that has carbon incorporated directly from the atmosphere at the time of formation. Tree rings have proven to be an excellent resource for this purpose. At the moment, the internationally-accepted absolutely-dated calibration curve based on North American and European tree-ring dated material only extends back to 12,410 years; the prospect of significantly extending the records in the northern hemisphere is not high due to destruction of material by past ice sheets. Buried in peat bogs across northern New Zealand are ancient conifer trees called kauri. We know of nowhere else in the world with such a rich resource of subfossil wood that is capable of capturing the complete range of radiocarbon. The time span preserved within these bogs is truly enormous; spanning more than 130,000 years. These trees are of vast proportions and almost perfectly preserved; individual trees can measure up to 4 metres across and live for up to 2000 years. Within this precious archive is an annual record of changing atmospheric radiocarbon levels and past climate. This is a unique resource. Unfortunately, however, the timber is also highly-prized for household furniture, arts and crafts. The result is the buried wood is being mined at an alarming rate and will be exhausted within ten years. In this project, we will collect and analyze the kauri before it is lost forever. We will focus on undertaking comprehensive dating of the tree rings to determine changing levels of radiocarbon in the atmosphere using ancient logs that have been collected within the period spanning 30,000 to 11,700 years ago. The results from this study will help to precisely calibrate radiocarbon-dated sequences of past climate, environmental and archaeological change, thereby helping us to improve our understanding the Earth system.

过去的气候变化提供了一个关键的基线，可以比较当前和未来的变暖。但是，不幸的是，尽管已经进行了最后的冰河时代的许多重建，但大多数记录都不能完全相互关联。主要的问题是，绝大多数记录是放射性碳的日期，不存在国际认可的校准曲线，从而排除了重建在日历时间表上的放置，并防止了与高分辨率和绝对约会序列（例如冰核）的强大比较。对于科学界来说，这是一个重要的问题。放射性碳年代记录的“校准”可以得出这样的结论：气候变化LED，滞后或在世界范围内同步，具体取决于使用哪种conversion依，从而阻止了科学界对地球系统变化机制的详细了解。准确，精确的放射性碳校准曲线应基于绝对日期的记录，该记录在形成时直接从大气中掺入碳。事实证明，树环是为此目的的绝佳资源。目前，基于北美和欧洲树木的材料的国际认可的绝对日期校准曲线仅延伸至12,410年。由于过去的冰盖破坏了材料，北半球记录的前景不高。埋葬在新西兰北部的泥炭沼泽中的是古老的针叶树，称为Kauri。我们知道世界上其他无处可去的亚物质木材资源，能够捕获完整的放射性碳。这些沼泽中保存的时间跨度确实是巨大的。超过130，000年。这些树的比例巨大，几乎完美保存；单个树木最多可以衡量4米，并寿命长达2000年。在这个宝贵的档案中，每年记录大气放射性碳含量和过去的气候。这是一个独特的资源。但是，不幸的是，木材也用于家具，手工艺品的高处。结果是埋藏的木材以惊人的速度开采，并在十年内耗尽。在这个项目中，我们将在丢失之前收集和分析kauri。我们将专注于对树环进行全面的约会，以确定大气中使用古老的原木在30,000至11,700年前收集的古老日志。这项研究的结果将有助于精确校准过去气候，环境和考古变化的放射性碳日期序列，从而帮助我们提高理解地球系统。

项目成果

Reanalysis of the Atmospheric Radiocarbon Calibration Record from Lake Suigetsu, Japan

• DOI: 10.1017/rdc.2020.18
• 发表时间: 2020-03
• 期刊: Radiocarbon
• 影响因子: 8.3
• 作者: C. Bronk Ramsey;T. Heaton;G. Schlolaut;R. Staff;C. Bryant;A. Brauer;H. Lamb;M. Marshall;T. Nakagawa

Punctuated Shutdown of Atlantic Meridional Overturning Circulation during Greenland Stadial 1.

• DOI: 10.1038/srep25902
• 发表时间: 2016-05-19
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Hogg A;Southon J;Turney C;Palmer J;Bronk Ramsey C;Fenwick P;Boswijk G;Friedrich M;Helle G;Hughen K;Jones R;Kromer B;Noronha A;Reynard L;Staff R;Wacker L
• 通讯作者: Wacker L

Statistical approaches and tools for IntCal20

IntCal20 的统计方法和工具

• DOI: 10.5194/egusphere-egu2020-9336
• 发表时间: 2020
• 作者: Bronk Ramsey C

New approaches to radiocarbon calibration arising from statistical developments in IntCal20

IntCal20 统计发展带来的放射性碳校准新方法

• DOI: 10.5194/egusphere-egu2020-9422
• 发表时间: 2020
• 作者: Bronk Ramsey C

Decadally Resolved Lateglacial Radiocarbon Evidence from New Zealand Kauri-CORRIGENDUM

来自新西兰贝壳杉的十年来解析的晚冰期放射性碳证据 - 勘误表

• DOI: 10.1017/rdc.2016.108
• 发表时间: 2016
• 期刊: Radiocarbon
• 影响因子: 8.3
• 作者: Hogg A