Doctoral Dissertation Research: Holocene Climate and Environmental Change in the Great Basin of the Western United States: A Paleolimnological Approach

博士论文研究：美国西部大盆地全新世气候与环境变化：古湖泊学方法

• 批准号: 1130340
• 负责人: David Porinchu
• 金额: $ 1.2万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1130340&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Holocene; Climate

Recent research in the Great Basin has demonstrated the need for quantitative, high-resolution temperature reconstructions that extend understanding of past thermal regimes further into the last 10,000 years. This doctoral dissertation research will assess recent environmental change and human-related influences on a suite of lakes in the central Great Basin, and it will develop high-resolution temperature reconstructions spanning the past 8,000 years, with an emphasis on the two most recent warm intervals, the Medieval Climate Anomaly and the Holocene Thermal Maximum. The doctoral student will gather data from a network of sites will be collected in the central Great Basin and analyze these materials in search of signals of past climatic changes. Lake sediments collected from this network will be measured for a variety of physical and biological indicators to include sub-fossil chironomids, sediment organic content, biogenic silica, mercury concentration, spheroidal carbonaceous particles, grain size, and macroscopic charcoal. These indicators will be used to characterize the recent temperature changes and pollution loadings along with long-term changes to productivity, temperatures, and fire histories in the region. Accurate chronological control will be ensured through lead-210 dating the recent sediment and accelerator mass spectrometer radiocarbon dates on sedimentary charcoal and identifiable plant remains. The results from the research will be compared with other paleoclimate reconstructions to gain a better understanding of the spatial and temporal climatic changes in the Great Basin.The results of this project will facilitate a more thorough examination of the influence of temperature on effective moisture and aridity in the Great Basin over the past 8,000 years. This will further contribute to basic understanding of the response of aquatic ecosystems to past and possibly future environmental change. Project results also should help identify how various human-related factors have influenced the structure and composition of these lakes during the most recent centuries. An ever-increasing supply of freshwater is required for the urban areas in the Great Basin, which have experienced dramatic population growth in recent decades. This research will help understand the long-term natural variability of thermal and moisture regimes for this region. The project also should help enhance decision making with regard to water policy and assist in adaptations to future climate variability and change. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

最近在大盆地的研究表明，需要进行定量的、高分辨率的温度重建，以进一步了解过去10,000年的热状况。 这项博士论文研究将评估最近的环境变化和人类对大盆地中部一系列湖泊的影响，并将开发跨越过去8,000年的高分辨率温度重建，重点是最近的两个温暖间隔，中世纪气候异常和全新世热最大值。 博士生将从中央大盆地收集的网站网络收集数据，并分析这些材料，以寻找过去气候变化的信号。 从这个网络收集的湖泊沉积物将测量各种物理和生物指标，包括亚化石摇蚊，沉积物有机含量，生物硅，汞浓度，球状碳质颗粒，粒度，宏观木炭。 这些指标将用于描述最近的温度变化和污染负荷沿着该区域生产力、温度和火灾历史的长期变化。 将通过铅-210测定最近沉积物的年代和加速器质谱仪测定沉积木炭和可识别植物遗骸的放射性碳年代，确保准确的年代控制。 研究结果将与其他古气候重建进行比较，以更好地了解大盆地的时空气候变化，该项目的结果将有助于更全面地研究过去8,000年来温度对大盆地有效湿度和干燥度的影响。 这将进一步有助于基本了解水生生态系统对过去和未来可能发生的环境变化的反应。 项目结果还应有助于确定近几个世纪以来各种与人类有关的因素如何影响这些湖泊的结构和组成。 大盆地的城市地区需要不断增加的淡水供应，近几十年来，大盆地的城市地区人口急剧增长。 这项研究将有助于了解该地区的长期自然变化的热和水分制度。 该项目还应有助于加强水政策方面的决策，并协助适应未来的气候多变性和变化。 作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。