Holocene Water Balance of the Northeastern Great Basin

该奖项支持生成稳定的同位素替代记录，以研究犹他州北部、爱达荷州东南部和怀俄明州西南部大盐湖(GSL)集水区的全新世水文气候学。该项目的样品来自DOSECC大陆钻探联盟钻探的岩心，并保存在国家LacCore储存库中。尽管在过去的5年里，对保存在这些岩心中的前全新世GSL沉积记录的研究取得了进展，但保存在全新世岩心中的古环境记录在很大程度上仍然没有被利用。该奖项支持对有机、矿物质和化合物特定稳定同位素比率的分析。从这些记录中得到的重建提供了美国西部这一地区跨越过去10,000年的全新世水循环的第一个高分辨率(近百年)记录。水文气候学重建被用来检验当地、区域和全球气候变化与该地区持续(十年至百年尺度)干旱时期之间的假想机制关系，并确定全新世期间全球和区域气候变化如何影响此类事件的频率和强度。除了提供气候假说的测试外，这些记录还为未来大盆地全新世环境变化的研究提供了基准。这项工作与地球系统历史计划所强调的“全新世气候可变性、强迫机制和影响”的研究领域特别相关。该项目的智力价值使人们更好地理解了美国西部的自然水文气候可变性。这些记录补充了内华达州和加利福尼亚州湖泊的相关数据集，揭示了水循环的时空变化。这些发现为正在进行的全新世植物群、动物群和考古学研究提供了重要的环境背景。这项工作为古气候模型者提供了数据目标，并使他们了解了驱动美国西部水循环变化的气候机制。它为拟议中的位于GSL盆地的水文观测站提供了史前背景。该项目还探索了稳定同位素古气候学的方法学进展，进一步利用蛋白质化石进行水文气候学研究，并利用多代理稳定同位素数据集重建过去的环境变化。广泛影响该奖项支持对一名女博士生的科学教育和培训，促进女性参与地球科学。在项目过程中，学生将在科学项目规划、分析和实验方法开发、稳定和放射性同位素分析、数据解释和建模以及研究成果的介绍和发布方面获得经验。该项目为本科生研究和普渡大学通过积极的少数民族参与方案招募的代表不足的群体的学生提供了参与的机会。研究结果通过出版、在主要科学学会年会上作介绍以及通过中央网络可访问门户网站(例如，编年史)分发数据，向科学界广泛传播。鉴于研究区水资源对未来气候变化的巨大潜在敏感性，这项研究具有社会相关性，预计将影响未来的水政策决策。通过普渡气候变化研究中心的活动，将知识从该项目转移到更广泛的科学和政策界。

This award supports the generation of stable isotope proxy records to study the Holocene hydroclimatology of the Great Salt Lake (GSL) catchment of northern Utah, southeastern Idaho, and southwestern Wyoming. Samples for this project are from cores drilled by the DOSECC continental drilling consortium and archived in the national LacCore core repository. Although study of the pre-Holocene GSL sedimentary record preserved in these cores has advanced during the last 5 years, the paleoenvironmental records preserved in the Holocene cores remain largely un-tapped. The award supports analyses of organic, mineralic, and compound-specific stable isotope ratios. Reconstructions derived from these records provides the first high-resolution (sub-centennial) records of the Holocene water cycle from this part of the western U.S. spanning the last 10,000 years. The hydroclimatological reconstructions are used to test hypothesized mechanistic relationships between local, regional, and global climatological change and periods of sustained (decadal to centennial scale) drought in this region, and to identify how global and regional climate change during the Holocene impacted the frequency and intensity of such events. In addition to providing tests of climate hypotheses, these records serve as a benchmark for future studies of Holocene environmental change in the Great Basin. The work is particularly relevant to the research area of "Holocene climatic variability, forcing mechanisms, and impacts" highlighted by the Earth Systems History program.Intellectual Merit The project generates improved understanding of natural hydroclimatological variability in the American West. The records generated complement related datasets from lakes in Nevada and California, revealing spatial and temporal changes in the water cycle. These findings benefit ongoing research on Holocene floras, faunas, and archaeology by providing important environmental context. The work provides data targets for paleoclimate modelers and informs their understanding of climate mechanisms driving water cycle change in the western U.S. It contributes pre-historical background for a proposed hydrological observatory to be located in the GSL Basin. The project also explores methodological advances in stable isotope paleoclimatology, furthering the use of proteinaceous fossils for hydroclimatological research and multi-proxy stable isotope datasets to reconstruct past environmental change.Broader ImpactsThis award supports the scientific education and training of a female Ph. D. student, advancing the participation of women in the Earth sciences. During the course of the project, the student will gain experience in scientific project planning, analytical and experimental methods development, stable and radiogenic isotope analysis, data interpretation and modeling, and presentation and publication of research results. The project presents opportunities for undergraduate research and for involvement of students from underrepresented groups recruited through active minority participation programs at Purdue. The results of the study are disseminated widely to the scientific community through publication, presentations at the annual meetings of major scientific societies, and data distribution via centralized web-accessible portals (e.g., CHRONOS). Given the great potential sensitivity of water resources in the study area to future climate change, the research is socially relevant and may be expected to impact future water policy decisions. Transfer of knowledge from this project to the broader scientific and policy communities is enhanced through the activities of the Purdue Climate Change Research Center.