Doctoral Dissertation Research: Using Ice-Core Data to Reconstruct Atmospheric Mercury Deposition Over the Past 17,000 Years.

这篇博士论文的目的是揭示北美西北部汞沉积的自然和人类控制。 人类的汞排放，主要来自采矿、冶炼和燃煤，目前正在上升，主要来自亚洲。 汞从亚洲向北美西北部的迁移可能会对生态和健康造成新的危害，导致河流和鱼类中汞含量已经很高。 然而，为了评估汞污染上升对生态系统的影响，还必须确定火山活动、风化和森林火灾产生的自然汞水平。 勘探者罗素山口（PRCol）冰芯，收集自山顶。2001年和2002年，加拿大育空地区的洛根是这项研究的理想选择，因为它位于亚洲污染源的下风处，而且它的记录跨越了过去17,000年。 这项研究将使用清洁取样技术和最先进的分析方法，以1至100年的时间尺度测量PRCol冰芯中的汞浓度。 冰芯中的汞浓度将与火山爆发、森林火灾、灰尘和气候的记录进行比较，以确定对汞水平自然变化的控制。 人类汞污染对这一地区的影响将通过比较20世纪沉积的汞浓度与大规模人类汞污染之前17，000年沉积的汞浓度来确定。 将通过比较20世纪世纪的气候参数和汞浓度来研究厄尔尼诺等气候模式对汞迁移和沉积的影响，确定近期汞污染的程度和趋势是解决全球环境汞污染问题的一个基本步骤。 研究结果将通过学术出版物和会议传播。将培训一名本科生研究助理，以协助这项研究并完成一个相关的分项目。 PI将在当地中学就他们的研究进行宣传，并将其与地球科学职业的讨论相结合。 国际合作将通过PI与加拿大研究人员之间的密切合作建立，这些研究人员收集并已经对冰芯数据进行了一些分析。作为博士论文研究改进奖，该项目将提供支持，使有前途的研究生建立一个独立的研究生涯。

The objective of this doctoral dissertation project is to reveal the natural and human controls on mercury deposition to northwestern North America. Human emissions of mercury, mostly from mining, smelting, and coal-burning, are currently rising, predominantly from Asia. The transport of mercury from Asia to northwestern North America may pose an emerging ecological and health hazard, contributing to already high levels of mercury in rivers and fish. However, in order to assess the impact of rising mercury pollution on the ecosystem, it is essential to also determine natural mercury levels through time, derived from volcanism, weathering, and forest fires. The Prospector Russell Col (PRCol) ice core, collected from the summit of Mt. Logan in the Yukon Territory of Canada in 2001 and 2002, is ideal for this study because of its location downwind from Asian pollution sources and its well-dated record spanning the past 17,000 years. This study will use clean sampling techniques and state-of-the-art analysis methods to measure mercury concentrations in the PRCol ice core at 1 to 100-year time scales. Mercury concentrations in this ice core will be compared to records of volcanic eruptions, forest fires, dust, and climate to determine the controls on natural changes in mercury levels. The impact of human mercury pollution on this region will be determined by comparing the concentrations of mercury deposited during the 20th century to concentrations deposited during the prior 17,000 years, before large-scale human mercury pollution. The influence of climate patterns such as El Nino on mercury transport and deposition will be investigated by comparing climate parameters and mercury concentrations during the 20th century.Determining the magnitude and trend of recent mercury contamination is a fundamental step in addressing the global issue of mercury pollution in the environment. Results of this research will be disseminated through academic publications and conferences. An undergraduate research assistant will be trained to assist in this research and to complete a related sub-project. The PIs will do outreach at local middle schools about their research, combining it with discussions of careers in the geosciences. International collaboration will be established through close work between the PIs and the Canadian researchers who collected and have already done some analysis of data derived from the ice core. As a Doctoral Dissertation Research Improvement award, this project will provide support to enable a promising graduate student to establish an independent researchcareer.