Climate Drivers and Ancient History in Greenland Ice

从极地冰盖收集的冰芯包含了过去环境条件、气候和气候驱动因素的详细记录。例如，大型火山爆发的时间、规模，有时甚至是地点都可以在冰中检测到。在过去，这种火山爆发通常与强烈的降温和降水模式的变化有关，这些变化破坏了粮食生产，导致饥荒、人类迁徙、政治动荡和冲突。1816年的一次这样的喷发导致了“没有夏天的一年”，导致整个北半球严重的食物短缺。同样，冰芯包含了过去工业排放金属、酸和其他污染物的详细记录。例如，铅污染是过去开采和冶炼铅/银矿石的一个特别敏感的指标，因为许多古代铸币是用银制成的，北极铅污染可以用作过去白银生产和整体经济活动的代理或指标。事实上，用最新的分析仪器在高深度分辨率下分析格陵兰冰芯，得出了古代、中世纪和现代经济的精确年代（在一到两年内）代用物。与已知的历史事件（如瘟疫和战争）相比，历史学家、经济学家和考古学家可以通过对外部冲击（如瘟疫的到来或火山爆发导致的气候破坏）的反应来评估过去社会的复原力。这项研究的目标是开发准确的日期，高分辨率，广泛的元素和化学物种的冰芯记录，以扩展和扩展最近确定的因果关系，1)古代社会；(2)火山作用和水文气候；(3)战争、瘟疫、社会动荡和经济活动。这些工作的基础将是收集和分析格陵兰冰盖东北侧翼图努地区约440米的冰芯。沿着冰芯站点上游的冰流线向上游延伸40公里的穿冰雷达调查将支持对气溶胶和水同位素记录的解释，以及对上游沉积过程变化的任何可能影响的理解。研究人员将利用沙漠研究所的连续流分析系统对冰芯进行分析，以确定30多种化学物质在过去4000年里与火山活动、生物质燃烧、海盐、大陆尘埃和工业污染有关的准确年代记录。冰芯的年代将通过火山限制的年度层数来确定，并辅以来自已知太阳质子事件的宇宙核素的测量。对冰芯记录的解释将由一个包括环境和气候科学家、火山学家、历史学家和社会科学家在内的跨学科团队进行。一个实验室为基础的课程也将开发培训历史学家，经济学家，考古学家和研究人员从其他相关领域的冰芯分析和如何冰芯记录可以用来解决历史研究问题。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。

Ice cores collected from the polar ice sheets contain detailed records of past environmental conditions, climate, and climate drivers. For example, the timing, size, and sometimes even the locations of large volcanic eruptions can be detected in the ice. Such eruptions often were linked in the past to periods of strong cooling and changes in precipitation patterns that disrupted food production, leading to famines, human migrations, political unrest, and conflict. One such eruption led to the 'year without a summer' in 1816, which resulted in major food shortages across the Northern Hemisphere. Similarly, ice cores contain detailed records of past industrial emissions of metals, acids, and other pollutants. For example, lead pollution is an especially sensitive indicator of past mining and smelting of lead/silver ores, and because many ancient coinage was made of silver, Arctic lead pollution can be used as a proxy or indicator past silver production and so overall economic activity. Indeed, Greenland ice cores analyzed at high depth resolution with the latest analytical instruments have yielded precisely dated (within one to two years) proxies of ancient, medieval, and modern economies. When compared to known historical events such as plagues and wars, historians, economists, and archaeologists can assess the resilience of past societies through their response to external shocks such as the arrival of plagues or a climate disruptions resulting from volcanic eruptions. The goal of this research is to develop accurately dated, high-resolution, ice-core records of a broad range of elements and chemical species to expand and extend recently identified, causal linkages between (1) ancient societies; (2) volcanism and hydroclimate; and (3) wars, plagues, social unrest, and economic activity. Underpinning these efforts will be the collection and analysis of a ~440 m ice core from the Tunu region on the northeastern flank of the Greenland ice sheet. An ice-penetrating radar survey extending 40-km upstream along the ice-flow line upstream of the ice-core site will support interpretation of the aerosol and water isotope records, as well as understanding of any possible impacts from changes in deposition processes upstream. The ice core will be analyzed using the continuous flow analysis system at the Desert Research Institute to develop accurately-dated records of over 30 chemical species linked to volcanism, biomass burning, sea salts, continental dust, and industrial pollution during the past 4,000 years. The ice core will be dated using volcanically-constrained annual layer counting supplemented by measurements of cosmogenic nuclides from known solar proton events. Interpretation of the ice-core records will be conducted by an interdisciplinary team including environmental and climate scientists, volcanologists, historians, and social scientists. A laboratory-based course will also be developed to train historians, economists, archaeologists, and researchers from other related fields in ice-core analysis and how ice-core records can be used to address historical research questions.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.