Early-concept grant for exploratory research (EAGER) proposal: Accessing the potential of clumped isotope thermometry to constrain temperatures in the Arctic during the Pliocene

探索性研究早期概念资助 (EAGER) 提案：利用聚集同位素测温技术限制上新世北极温度的潜力

• 批准号: 1215551
• 负责人: Aradhna Tripati
• 金额: $ 23.59万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1215551&HistoricalAwards=false
• 关键词: Early; concept; grant; exploratory; research

The specific goal of this research is to identify whether carbonate ?clumped isotope? thermometry can be applied to mollusks to accurately and precisely reconstruct temperatures in the Arctic. Previous work has shown that the occurrence of multiple rare isotope substitutions in carbonate minerals, also referred to as the ?clumping? of heavy isotopes into bonds with each other, is temperature dependent. This temperature proxy is also independent of the del-18O of water and the del-13C of dissolved inorganic carbon. Initial studies of biologically-precipitated calcite and aragonite by the PI and co-PI and collaborators indicate that the measurements of 13C-18O bond abundance should allow one to make a relatively assumption-free determination of the temperature at which a mineral formed. Although this new proxy looks promising, calibration of the clumped isotope thermometer at low temperatures (i.e., below 15°C) is limited. Therefore the utility of this proxy for climate reconstructions in the Arctic is unclear. This project will determine the accuracy and precision of the technique when applied to biological samples grown at Arctic temperatures and, consequently, the ability of this technique to assess paleo ocean temperatures in polar regions.The instrumental record of temperature only goes back in time a few hundred years, at most. In order to understand the natural variability of temperature, either locally or globally, we require much longer records. To develop such records, we rely on proxy measurements for temperature. Use of such proxies requires assumptions and often imposes large error bars on the estimated temperature. This project will determine the usefulness of a new proxy in the polar regions.

这项研究的具体目标是确定碳酸盐“聚集同位素”测温法是否可以应用于软体动物，以准确、精确地重建北极的温度。先前的研究表明，碳酸盐矿物中存在多种稀有同位素替代。由于重同位素彼此“聚集”成键，因此该温度代理也与水的 del-18O 和溶解的 del-13C 无关。通过 PI 和 co-PI 以及 co-PI 和 co-PI 和文石对生物沉淀方解石和霰石的初步研究表明，13C-18O 合作键丰度的测量应该允许人们做出相对无假设的结果。确定矿物形成的温度虽然这种新的替代物看起来很有前景，但在低温（即低于 15°C）下对结块同位素温度计的校准是有限的，因此这种替代物在气候重建中的效用受到限制。该项目将确定该技术应用于在北极温度下生长的生物样本时的准确性和精确度，从而确定该技术评估极地地区古海洋温度的能力。温度的仪器记录仅存在为了了解当地或全球温度的自然变化，我们需要更长的时间来记录，我们依赖于温度的替代测量。该项目经常对估计温度施加较大的误差线。将决定新代理在极地地区的有用性。