Testing amino acid paleothermometry in radiocarbon-dated lake sediment

测试放射性碳测年湖泊沉积物中的氨基酸古温度测定法

• 批准号: 2317409
• 负责人: Darrell Kaufman
• 金额: $ 60.05万
• 依托单位: Northern Arizona University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317409&HistoricalAwards=false
• 关键词: Testing; amino; acid; paleothermometry; radiocarbon

Testing amino acid paleothermometry in radiocarbon-dated lake sedimentClimate change poses a major challenge for society. More information is needed to put recent climate changes into a long-term context of natural climate variability. This information helps to foresee possible future climate trends, especially those that involve slow-moving features of the climate system, which will continue to evolve over hundreds to thousands of years to come. A variety of geological evidence can be used to extend observations of temperature and other climate variables back in time. This project focuses on developing a new method of estimating temperature changes extending back thousands of years by using amino acids contained in lake sediment. The extent to which these molecules have been degraded depends largely on the temperature of the environment in which they have been stored and the length of time since they were formed. This project will use laboratory experiments to determine the temperature sensitivity of different degradation reactions coupled with radiocarbon dating to determine the age of the enclosing lake sediment. Funding will also be used to sustain the shared use of the Amino Acid Geochronology Laboratory at Northern Arizona University, which is the only one of its type in the United States. The project will also prepare undergraduate and graduate students for careers in the STEM workforce.Developing new methods to quantify past temperature is a high priority for climate science. The extent to which amino acids (AAs) in geologic settings have been chemically altered is primarily determined by the length of time elapsed since the molecules formed and by the ambient post-depositional temperature. Coupled with independent age control though radiocarbon (14C) dating, chemical reactions involving AAs can been used to quantify the timing and magnitude of past temperature changes. AAs are abundant in lake sediment, which has generally accumulated continuously in lakes over thousands of years, and thereby can be analyzed in detailed time series from widely distributed sites. This project will generate the first major AA dataset on 14C-dated and laboratory heated lake sediment. This project builds on a growing number of studies of AAs in lake sediment and it takes advantage of NSF-supported lake-core community resources. This award will sustain the Amino Acid Geochronology Laboratory as research infrastructure, enabling it to continue its long tradition of training users, offering pilot-study analyses, and assisting with data interpretation and curation. This project will also support STEM graduate and undergraduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在放射性碳定年湖泊沉积物中测定氨基酸古温度值气候变化是社会面临的重大挑战。需要更多的信息将最近的气候变化置于自然气候变率的长期背景下。这些信息有助于预测未来可能的气候趋势，特别是那些涉及气候系统缓慢移动特征的趋势，这些特征将在未来数百年至数千年继续演变。各种地质证据可以用来延长对温度和其他气候变量的观测时间。这个项目的重点是开发一种新的方法，通过使用湖泊沉积物中含有的氨基酸来估计几千年前的温度变化。这些分子被降解的程度在很大程度上取决于储存它们的环境的温度和它们形成后的时间长短。该项目将使用实验室实验来确定不同降解反应的温度敏感性，并结合放射性碳定年法来确定围湖沉积物的年龄。资金还将用于维持北亚利桑那大学氨基酸地质年代学实验室的共享使用，该实验室是美国同类实验室中唯一的一个。该项目还将为本科生和研究生在STEM领域的职业生涯做好准备。发展量化过去温度的新方法是气候科学的当务之急。氨基酸在地质环境中发生化学变化的程度主要取决于分子形成后经过的时间长度和沉积后的环境温度。再加上通过放射性碳（14C）测年的独立年龄控制，涉及原子吸收剂的化学反应可以用来量化过去温度变化的时间和幅度。湖泊沉积物中AAs含量丰富，湖泊沉积物通常是在数千年的时间里连续积累的，因此可以从广泛分布的地点进行详细的时间序列分析。该项目将生成第一个主要的14c测年和实验室加热湖泊沉积物的AA数据集。该项目建立在越来越多的湖泊沉积物中AAs研究的基础上，并利用了美国国家科学基金会支持的湖核群落资源。这笔奖金将维持氨基酸地质年代学实验室作为研究基础设施的地位，使其能够继续其培训用户的悠久传统，提供试点研究分析，并协助数据解释和管理。该项目也将支持STEM研究生和本科生。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。