Abrupt Climate Change During the Last Interglacial: Testing a New Approach to U-Series Coral Dating and Sea-Level Reconstruction

末次间冰期期间气候突变：测试 U 系列珊瑚测年和海平面重建的新方法

• 批准号: 0602383
• 负责人: William Thompson
• 金额: --
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0602383&HistoricalAwards=false
• 关键词: Abrupt; Climate; Change; During; Last

Abrupt Climate change during the Last Interglacial: Testing a new approach to U-series coral dating and sea level reconstruction.AbstractThe objectives of this project are twofold: First, we will test a promising new approach to U/Th coral dating and sea level reconstruction. Second, we will test an emerging hypothesis that sea level during the last interglacial was quite variable. The most pressing problem in U/Th dating of older fossil corals is a well-documented disturbance of the U-series isotopes that are used for dating, thereby creating a paucity of specimens for analysis. Recent advances in U/Th dating of corals suggest that it is possible to correct for these disturbances, thereby producing coherent and reproducible results. Sea level reconstructions using corrected ages suggest that last interglacial sea level was more variable that previously thought. If these implied sea-level oscillations are in fact real, it has serious implications regarding the stability of our present climate and requires a rethinking of proposed mechanisms for rapid climate change. In this proposal, we will conduct high-resolution sampling of outcrops of last interglacial fossil reefs at Barbados, the Bahamas, and Western Australia in order to analyze the age reproducibility of corals within and between samples. Agreement of ages within stratigraphic layers will provide strong support for their accuracy and differences will help define the limits and precision of the method. Discrepancies within and between individual records will guide future efforts in sea-level reconstruction. If this new approach proves robust, it will lead to significant improvements in sea level chronologies for the past 600,000 years and will provide a more complete database for future research on the mechanisms and ice sheet response to rapid climate change. This project will fund a new PI and will involve undergraduates from Smith College and Wooster College of Ohio in sampling and mapping fieldwork.

在末次间冰期的突然气候变化：测试一种新的方法，以U-系列珊瑚定年和海平面reconstruction.AbstractThe的目标，这个项目是双重的：首先，我们将测试一个有前途的新方法，以U/Th珊瑚定年和海平面重建。其次，我们将测试一个新兴的假设，即海平面在最后一次间冰期是相当可变的。 在U/Th年代测定老化石珊瑚的最紧迫的问题是一个有据可查的干扰的U系列同位素，用于定年，从而创建一个缺乏标本的分析。 珊瑚的U/Th测年的最新进展表明，有可能纠正这些干扰，从而产生连贯和可重复的结果。 海平面重建使用校正的年龄表明，最后一次间冰期海平面是更可变的，以前认为。 如果这些隐含的海平面振荡事实上是真实的，它对我们目前气候的稳定性有严重的影响，需要重新思考快速气候变化的拟议机制。 在本提案中，我们将对巴巴多斯、巴哈马和西澳大利亚的末次间冰期化石礁露头进行高分辨率采样，以分析样本内和样本之间珊瑚的年龄再现性。 地层内年龄的一致性将为其准确性提供强有力的支持，差异将有助于确定该方法的限度和精度。 个别记录内部和之间的差异将指导未来的海平面重建工作。如果这一新方法被证明是可靠的，它将导致过去60万年海平面年表的重大改进，并将为未来研究快速气候变化的机制和冰盖反应提供更完整的数据库。 该项目将资助一个新的PI，并将涉及来自史密斯学院和俄亥俄州的伍斯特学院的本科生在采样和测绘实地工作。