Collaborative Research: Investigating Geochemical Signatures in Greenland ice of a Possible Extraterrestrial Impact During the Younger Dryas Climate Event

合作研究：调查新仙女木气候事件期间可能受到外星影响的格陵兰冰的地球化学特征

• 批准号: 1417476
• 负责人: Paul Mayewski
• 金额: $ 3.36万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417476&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigating; Geochemical; Signatures

The primary objective of the proposed research is to obtain records of platinum, iridium, and osmium concentrations and osmium isotope ratios in the GISP2 Greenland ice core in order to investigate the hypothesis that there was a meteorite or comet impact at the onset of the Younger Dryas abrupt climate event 12,900 years ago. These analyses will be combined with high-resolution measurements of climate proxies obtained on the same samples. Osmium isotopes have the potential not only to conclusively confirm or refute the presence of an extraterrestrial impact, but also to provide information about the size and type of the impactor, should one be confirmed. High-resolution analyses of the atmospheric circulation proxies sodium, calcium, and iron represent a leap in ice core analysis resolution from one sample per three years to over 100 samples per year. The proposed research activities would contribute towards an understanding of what happened at the Younger Dryas, which will be of broad interest to geologists, geochemists, climatologists, archeologists, astronomers, and the general public. Following recent reports of a large anomaly in platinum concentration in the GISP2 ice core, four investigators propose a series of collaborative analyses at Dartmouth College and the University of Maine on GISP2 ice core samples of Younger Dryas age to: (1) evaluate the platinum spike at the Younger Dryas onset for potential contamination and contributions from volcanic and terrestrial sources, (2) measure osmium concentration and isotope composition to evaluate whether an impact occurred at the Younger Dryas onset and assess the nature of any impactor, and (3) assess the environmental change across this critical climate transition by measuring iron, sodium and calcium at storm-scale resolution using a new laser ablation mass-spectrometry system. The proposed research will provide students with opportunities for engaged learning in order to increase their interest and knowledge of how geochemical investigations provide insights to climate change affecting the Arctic. In particular, this study will constitute a major portion of a Ph.D. thesis and an undergraduate Senior Thesis. It will expose graduate and undergraduate students to cutting-edge geochemical and mass spectrometric techniques.

拟议的研究的主要目的是获得GISP2 Greenland Ice Core中铂，虹膜和oSmium浓度和同位素比的记录，以便研究以下假设：在年轻的Dryas Primatiate事件发生在12900年之前，在年轻的Dryas Primatiate事件开始时会产生陨石或彗星的影响。这些分析将与在同一样品上获得的气候代理的高分辨率测量结合。 osmium同位素不仅有可能确认或反驳地球外影响的存在，而且还可以确认有关影响器的大小和类型的信息。大气循环代理，钙和铁的高分辨率分析代表了冰芯分析的飞跃，从每三年的一个样本到每年100多个样本。拟议的研究活动将有助于了解年轻的Dryas发生的事情，这将是地质学家，地球化学家，气候学家，考古学家，天文学家和公众的广泛关注。在最近关于GISP2 ICE核心铂浓度大量异常的报道之后，四名研究人员在达特茅斯学院和缅因州大学对GISP2 ICE核心年龄的样本进行了一系列协作分析，以：（1）评估年轻的Dryas和Terranim inserial soility and sermious and sermious and serive and serive（2）（2）2（1）为了评估在年轻的Dryas发作中是否发生撞击并评估任何影响因素的性质，以及（3）使用新的激光消融质谱系统在暴风雨规范下测量铁，钠和钙来评估这种关键气候过渡的环境变化。拟议的研究将为学生提供参与学习的机会，以增加他们对地球化学调查如何为影响北极的气候变化提供见解的知识。特别是，这项研究将构成博士学位的重要部分。论文和本科高级论文。它将使毕业生和本科生接触到尖端的地球化学和质谱技术。